LOCK-IN AMPLIFIER MODULE

LI5501 / LI5502
INSTRUCTION MANUALNF Corporation

DA00098273-003

LOCK-IN AMPLIFIER MODULE

LI5501 / LI5502
INSTRUCTION MANUAL

Registered Trademarks
National Instruments and LabVIEW are registered trademarks of National
Instruments Corporation in the United States.
Other company names and product names used in this instruction manual may be
trademarks or registered trademarks of their respective companies.

Preface――― Preface ―――
Thank you for purchasing the “LI5501 / LI5502 LOCK-IN AMPLIFIER MODULE”.
For safe and correct use of this instrument, please read the “Safety Precautions”
section that follows before attempting to use the instrument.
⚫ Marks and Symbols
For safe operation by the user and to prevent damage to the instrument, please
give attention to the following marks and symbols that are used in this manual.
！ WARNING

This mark indicates information for preventing the possibility of death or serious
personal injury from electrical shock or other hazards in the use or handling of
this instrument.

！ CAUTION

This mark indicates information for preventing the possibility of injury to the user
or damage to the instrument in the use or handling of this instrument.

i

LI5501 / LI5502

Preface⚫ The chapters of this manual are described below.
If you are using this instrument for the first time, begin reading from Chapter 1.
1. Introduction
This chapter describes a general description of the instrument, including its
features, applications, functions, and basic operating principles.
2. Preparation before use
This chapter describes important preparation that must be done before operating
the instrument.
3. Names of each part
This chapter describes names and functions of each part.
4. Basic settings
This chapter describes basic settings of the “LI5501 / LI5502”.
5. Remote control
This chapter describes remote control commands of the “LI5501 / LI5502”.
6. Advanced settings
This chapter describes advanced settings of the “LI5501 / LI5502”.
7. TroubleshootingThis chapter describes how to deal with error messages and cases in which you
think the instrument is malfunctioning.
8. MaintenanceThis chapter describes storage, repacking, transportation, and performance
testing methods.
9. Specifications
This chapter describes the instruments specifications (functions andperformance).

ii

LI5501 / LI5502

Safety Precautions――― Safety Precautions ―――
For safe use of this product, give full attention to the following warnings and cautions.
The NF Corporation shall not be held liable for damages that arise from failure to observe
these warnings and cautions.
⚫ Be sure to observe the contents of instruction manual.
This instruction manual contains information for the safe operation and use of this
instrument.
Be sure to read this instruction before using this instrument.
All of the warning items contained in this instruction are intended to avoid risks that
may lead to serious accidents. Follow the warnings and instructions carefully.
⚫ Check the power supply voltage.
This instrument operates on the power source voltage described in “2.3 Grounding andpower connections”.
Before supplying power to this instrument, confirm that the supply voltage conforms to
the rated power supply of this instrument.
⚫ If you think something is wrong, …
If smoke or an unusual odor or sound comes from this instrument, immediately remove
the power cord of the power supply from the outlet and cease use of this instrument.
If any such abnormality occurs, take measures to prevent the use of this instrument
until repairs have been completed and promptly contact the NF Corporation or its
authorized agent.
⚫ Do not use this instrument in explosive atmosphere.
An explosion or other hazards may occur.
⚫ Do not open the instrument cover.
Because there are precision electronic components inside this instrument, never remove
the instrument cover.
Only technicians certified by the NF Corporation are authorized to inspect and touchanything inside the instrument cover.
⚫ Do not modify this instrument.
Never modify this instrument in any way. Modification might create new risks. The NF
Corporation may refuse to service an instrument that has an unauthorized modification.

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LI5501 / LI5502

Safety Precautions⚫ Do not expose this product to water.
Use of this instrument when it is wet may result in malfunction. If this instrument
becomes wet, immediately unplug the power cord of the power supply and contact the
NF Corporation or its authorized agent.
⚫ If lightning occurs nearby, unplug the power cord.
A lightning strike may cause electrical shock, fire, or malfunction.
Immediately turn off the power supply and unplug the power cord of it.
⚫ Safety-related symbols
The marks and symbols defined below are used in this manual or on the instrument
itself to indicate safety information or instructions.
Instruction Manual Reference SymbolThis symbol notifies the user of a potential hazard andindicates that the user must refer to the instruction manual.

WARNING

Warning SymbolThis mark indicates information for preventing the possibility

WARNINGof death or serious personal injury from electrical shock or otherhazards in the use or handling of this instrument.

CAUTION

Caution SymbolThis mark indicates information for preventing the possibility

CAUTIONof injury to the user or damage to the instrument in the use or
handling of this instrument.

⚫ Other Symbols
This symbol indicates that connected to the instrument case.
This symbol indicates that the outer conductor of the connector isisolated from the instrument enclosure.
However, safe operation of the instrument requires that thepotential difference from the grounding potential is restricted to 42
Vpk or less.
This instrument must be grounded when in use, so the power
supply must be grounded.

iv

LI5501 / LI5502

Safety Precautions⚫ Electromagnetic compatibility
Applied EMC standard: EN 61326-1, EN 61326-2-1
Intended electromagnetic environment: Industrial
Emissions, which exceed the levels required by that standard, can occur when thisproduct is connected to a test object.
This product is a CISPR 11 Group 1 Class A equipment.
This product may cause interference if used in residential areas. Such use must be
avoided unless the user takes special measures to reduce electromagnetic emissions toprevent interference to the reception of radio broadcasts.
！ CAUTION

This product is not intended for use in residential environments and may not provide
adequate protection to radio reception in such environments.

⚫ Disposal of this instrument
To protect the environment, follow the guidelines described below for the disposal of this
instrument.
a) This instrument does not use batteries.
b) Use the services of an industrial waste disposal contractor for disposal of this
instrument.

v

LI5501 / LI5502

Table of contents
Page

1． Introduction .................................................................................................1-1
1.1 Features ..................................................................................................................... 1-2
1.2 Applications................................................................................................................ 1-3
1.3 Operating principle..................................................................................................... 1-4

2． Preparation before use ...............................................................................2-1
2.1 Inspection................................................................................................................... 2-2
2.2 Installation .................................................................................................................. 2-3
2.3 Grounding and power connections ............................................................................ 2-6
2.4 Firmware update ........................................................................................................ 2-7
2.5 Calibration .................................................................................................................. 2-7

3． Names of each part.....................................................................................3-1
3.1 Names and functions of each part ............................................................................. 3-2
3.2 I/O connectors............................................................................................................ 3-4
3.3 Power-on.................................................................................................................... 3-9

4． Basic settings ..............................................................................................4-1
4.1 Setting items .............................................................................................................. 4-2
4.2 Initial settings ........................................................................................................... 4-15

5． Remote control ...........................................................................................5-1
5.1 Preparation before use .............................................................................................. 5-2
5.2 List of commands and command tree ....................................................................... 5-5
5.3 Commands............................................................................................................... 5-10
5.4 Status system .......................................................................................................... 5-39
5.5 Error messages ....................................................................................................... 5-49

6． Advanced settings.......................................................................................6-1
6.1 Measurement data buffer........................................................................................... 6-2
6.2 Configuration memory ............................................................................................... 6-8
6.3 FAN control ................................................................................................................ 6-9

7． Troubleshooting ..........................................................................................7-1
7.1 Error messages ......................................................................................................... 7-2
7.2 Abnormalities during measurement ........................................................................... 7-3

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LI5501 / LI5502

Table of contents

8． Maintenance ...............................................................................................8-1
8.1 Introduction ................................................................................................................ 8-2
8.2 Daily maintenance ..................................................................................................... 8-3
8.3 Storage, repacking, and transport ............................................................................. 8-3
8.4 Checking the version number .................................................................................... 8-3
8.5 Performance tests...................................................................................................... 8-4
8.6 Calibration ................................................................................................................ 8-12

9． Specifications ..............................................................................................9-1
9.1 Input section............................................................................................................... 9-2
9.2 Output section ............................................................................................................ 9-4
9.3 Analysis function ........................................................................................................ 9-5
9.4 Digital data output .................................................................................................... 9-10
9.5 Remote control interface.......................................................................................... 9-10
9.6 Miscellaneous specifications ................................................................................... 9-11
9.7 External dimensions ................................................................................................ 9-13vii

LI5501 / LI5502

Figures and Tables
Page
Figure 1-1 Basic principle of Lock-in Amplifier...................................................................... 1-4
Figure 1-2 Block diagram of the LI5501 / LI5502 ................................................................. 1-6
Figure 3-1 Top side ............................................................................................................... 3-2
Figure 3-2 Rear side ............................................................................................................. 3-3
Figure 5-1 Common command syntax................................................................................ 5-10
Figure 5-2 Subsystem command syntax ............................................................................ 5-11
Figure 5-3 Numerical parameter syntax (<NRf>) ............................................................... 5-13
Figure 5-4 Numerical parameter syntax (<NR1>) .............................................................. 5-13
Figure 5-5 Numerical parameter syntax (<NR2>) .............................................................. 5-13
Figure 5-6 Numerical parameter syntax (<NR3>) .............................................................. 5-14
Figure 5-7 Mantissa syntax ................................................................................................. 5-14
Figure 5-8 Exponent syntax ................................................................................................ 5-14
Figure 5-9 Discrete parameter syntax (<DISC>) ................................................................ 5-15
Figure 5-10 Boolean parameter syntax (<BOL>) ............................................................... 5-15
Figure 5-11 Text string parameters (<STR>) ...................................................................... 5-16
Figure 5-12 Suffix syntax .................................................................................................... 5-16
Figure 5-13 Program message syntax................................................................................ 5-17
Figure 5-14 Response message syntax ............................................................................. 5-17
Figure 5-15 Integer response data syntax (<NR1>) ........................................................... 5-18
Figure 5-16 NR2 numerical response data syntax (<NR2>) .............................................. 5-18
Figure 5-17 NR3 numerical response data syntax (<NR3>) .............................................. 5-18
Figure 5-18 Discrete response data syntax (<DISC>) ....................................................... 5-19
Figure 5-19 Numerical Boolean response data syntax (<NBOL>) ..................................... 5-19
Figure 5-20 Text string response data syntax (<STR>) ...................................................... 5-19
Figure 5-21 Defined-length arbitrary block response data syntax (<DBLK>) .................... 5-20
Figure 5-22 Status system .................................................................................................. 5-39
Figure 5-23 Structure of the standard event status ............................................................ 5-41
Figure 5-24 Structure of the operation status ..................................................................... 5-43
Figure 5-25 Structure of the questionable status................................................................ 5-46
Figure 9-1 External dimensions of the LI5501 .................................................................... 9-13
Figure 9-2 External dimensions of the LI5502 .................................................................... 9-14

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LI5501 / LI5502

Figures and Tables

Table 2-1 Packing list ............................................................................................................ 2-2
Table 4-1 Setting items and initial values............................................................................ 4-15
Table 5-1 Common commands ............................................................................................. 5-5
Table 5-2 Subsystem commands .......................................................................................... 5-5
Table 5-3 Keywords that can be interpreted or not ............................................................. 5-12
Table 5-4 Definitions of the status byte register.................................................................. 5-40
Table 5-5 Contents of the standard event status register ................................................... 5-42
Table 5-6 Contents of the operation status condition register ............................................ 5-44
Table 5-7 Transition filter settings and the event register transitions ................................. 5-45
Table 5-8 Contents of the questionable condition register ................................................. 5-47
Table 5-9 Transition filter settings and the event register transitions ................................. 5-48
Table 5-10 Error messages ................................................................................................. 5-49
Table 6-1 Measurement data parameters ............................................................................. 6-2

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(Blank)x

LI5501 / LI5502

1． Introduction

1.1 Features ...............................................................1-2
1.2 Applications ..........................................................1-3
1.3 Operating principle ...............................................1-4
1.3.1 Basic principle of Lock-in Amplifier ............................. 1-4
1.3.2 Block diagram ............................................................. 1-6

1-1

LI5501 / LI5502

1.1 Features

Features

1.1

The “LI5501 / LI5502 LOCK-IN AMPLIFIER MODULE” is a dual-phase lock-in amplifier
module with a frequency range of 10 mHz to 1 MHz.
They can be widely used to measure amplitude and a phase of small AC signal buried innoise taking advantage of the following features. The LI5502 can measure amplitude ratio
and phase difference between two channels.
• Wideband
A signal from 10 mHz to 1 MHz can be measured.
• Dual-phase lock-in amplifier
Because phase detection and subsequent processing are performed digitally, an output
zero drift and orthogonal error are much smaller than an analog method.
By mounting two of these phase detectors, amplitude (R = √(X2+Y2)) and a phase (θ =−tan 1 (Y / X)) of a signal can be measured.
The two-channel model LI5502 is equipped with the two dual-phase detectors (samereference frequency), so amplitude ratio and phase difference between two channels canbe measured.
• Fractional harmonic measurement
In addition to harmonic measurement, a frequency of submultiple of fundamental wave
(x 1 / 1 to 63 / 64) can be used as reference frequency.
• Variety of filters
This instrument is equipped with the time constant filter and moving average filter.
a)Time constant filter
The attenuation slope of the filter can be set to 6, 12, 18, or 24 dB/oct.
The minimum time constant of 1 μs enables fast response.

b)Moving average filter
This instrument is equipped with the moving average filter after the time constantfilter. This filter can be set the averaging time from 1 μs to 100 s.
Fast response can be obtained in low frequency measurement when this filter is
combined with the time constant filter in appropriate setting.

• Smooth output response
The maximum update rate is approximately 300 k Samples/s, and the amplituderesolution is 16 bits.
• External synchronization
This instrument can be synchronized with reference frequency of another instrument byusing the 10 MHz IN terminal.

1-2

LI5501 / LI5502

1.2 Applications• Remote control
Setting changes and measurement data reception are performed via USB or LAN
communication. The maximum transfer rate of measurement value is 300k words/s.
• Small size
200 mm (W)×25 mm (H)×150 mm (D), approximately A5 size
It is easy to mount the instrument on equipment by using the attached metal fittings.

1.2

Applications

The LI5501 / LI5502 can be used in the following fields, taking advantage of its features.
• Signal detection in scanning probe microscope• Thermal diffusivity measurement of thin film materials• Spectroscopic analysis(material science using Auger electron spectroscopy and Raman spectroscopy)• Analyses of mechanical vibration• Noise measurement of electronic components◼ Application example using the LI5502
The following measurement can be performed using functions of the LI5502.
⚫ Low-impedance measurement
In impedance measurement of samples whose characteristics change or that aredamaged by several mA current, a method of increasing an applied voltage cannot be
used because the current value increases with the voltage.
Alternatively, a small current is applied to the sample, and the voltage and current
applied to the sample are amplified by a low-noise voltage amplifier and current
amplifier, respectively.
The impedance equivalent value can be obtained by measuring the respective output
voltages of the amplifiers and calculating with the LI5502.
Voltage preamplifier

a

CH-A

z

v

RATIO = a / b

Current preamplifier

DUT

DATA
OUT

PHASE = a − b
CH-B

b

i
Resistor
Voltage / current conversion

1-3

OSC
OUT

INT OSC

LI5502LI5501 / LI5502

1.3 Operating principle

Operating principle

1.3

1.3.1 Basic principle of Lock-in Amplifier
A lock-in amplifier is a device that uses difference of frequencies to separate an signal andnoise and amplify the signal. It works equivalently as a tuned amplifier or narrow band
pass filter where the center frequency follows the signal.
PSD

LPF

R = √(X2 + Y2)
θ = tan-1(Y / X)

DC AmpY OUT

Signal
+
Noise

R

f0

+90° Phase Shifter
ADC

Phase
shift
er

θ

X OUT

θ

SIG INR cos θX

Equivalent

Phase Shifter

REF IN
f0

LPF± 180°SIG IN
SignalDC

OUT

Saturation levelfC

Amplitude

DC + 2 f 0+ Noisesin(2πf 0t + θ) sin(2πf 0t)= ((cos θ - cos(4πf 0t + θ)) / 2

Amplitude

SignalvectorY

R sin θ

0
(DC)

Noise

BPF
2fC

f0
Signal2 f0
RippleFrequency conversion
LPF

SIG IN ×

DC Gain

Signal gain
Noise gain

(No LPF)

DR = DC Gain

Figure 1-1 Basic principle of Lock-in Amplifier
Firstly, a signal including noise is converted to a DC voltage using a Phase Sensitive
Detector (PSD). At this point, noise in the vicinity of the signal frequency is also converted
to the vicinity of DC. Then, the noise and ripples caused by the detection are removed
using a low pass filter (LPF) to obtain the DC component. When this is returned to theoriginal frequency, the equivalent bandwidth is equal to the band pass filter that is double
the cutoff frequency of the LPF. Increasing the time constant (response time) andattenuation slope of the LPF decreases the cutoff frequency, so more noise can be removed.
After the noise is removed using the LPF, the DC signal can be amplified without being
saturated by the noise. In short, the original signal can be measured even though the noise
is greater than the signal. DC gain after the PSD are determined by the sensitivity (fullscale of signal voltage) and dynamic reserve (DR) setting.
(DR value = Allowable maximum noise level / Voltage sensitivity)

1-4

LI5501 / LI5502

1.3 Operating principle

A lock-in amplifier needs a reference signal as reference of frequency and phase. The PSD
is a multiplier of a measured signal and reference signal (both are sine waves and thesame frequency). The PSD output is dependent on the amplitude of the measured value (R)and the phase (θ) difference from the reference signal. The amplitude of the reference
signal applied to the PSD is constant, and the phase of it can be shifted.
A dual-phase lock-in amplifier is equipped with the two PSDs, and works as a vector
voltmeter that can obtain two orthogonal components X and Y (in other words, R and θ)
simultaneously.
The LI5502 is equipped with two dual-phase PSDs, so two signals can be measured
simultaneously using a single reference signal.
The internal oscillator is usually synchronized with an external reference signal by PLL
and supplies a reference signal to the PSD. Its frequency can be set numerically and it can
supply its harmonic to the PSD as a reference signal.

1-5

LI5501 / LI5502

1.3 Operating principle

1.3.2 Block diagram
The block diagram of the LI5501 / LI5502 is presented and its main functions are
explained.

A IN

AC GAIN
Buf

A/D

Buf

A/D

B IN is LI5502 only

B IN
POWER
REGULATOR
1Vrms± 15 VDCDC GAINTC, SLOPE
PSD

OFFSET

MOV
EXPAND

DATA1

X
D/A

Buf

Y

X

CALCULATE

+90 ﾟ

DATA2
D/A

Buf
± 10 V

USB
Y
CPU
+90 ﾟ

FREQUENCYINT OSCREF IN

PHASE
xn

PHASE
SHIFTER 1

xn

PHASE
SHIFTER 2

xn

PHASE
SHIFTER 3

PLL

Cmp

10MHz IN

1/m

ISOLATION

LAN

n/m

D/A

DC BIASOSC OUTD/A[ FPGA ]

1Vrms
TTL

Figure 1-2 Block diagram of the LI5501 / LI5502

1-6

LI5501 / LI5502

1.3 Operating principlea) Signal input section
Input connector selection (A IN, B IN*)
Two input signal channels are provided*. Two input signals can be detected to samereference signal.
*LI5502 only
Signal amplification (AC GAIN)
A signal with noise is amplified in the frequency band. The dynamic reserve affects
AC GAIN and DC GAIN.
This instrument can be used in combination with our low-noise amplifiers, etc.
Sampling (A/D)
An input signal is converted to a 16-bit digital signal at a sampling rate of
2.5 M Samples/s.
b)Detector (DETECTOR CKT)
Phase sensitive detection (PSD)
A frequency of signal is converted to a DC voltage using a Phase Sensitive Detector(PSD).
The amplitude and phase of a signal can be obtained by detecting it using two
orthogonal phases. Phase sensitive detection is accomplished by multiplexing an
input signal and internal reference signal. Since a reference signal applied to the
PSD is a sine wave, there is no influence of harmonics of input signal, whichbecomes a problem when a simple square wave is used as reference signal. A ripple
doubling a signal frequency occurs in the product of a measured signal andreference signal, and another ripple that equals to signal frequency occurs in the
product of an input DC offset and reference signal, but they are removed by the time
constant filter in the next stage. A lock-in amplifier only measures AC signals so it
has the advantage that it is not affected by the thermal electromotive force that is a
DC signal.
Time constant filter (TC, SLOPE)
A time constant filter removes noise and ripples caused by the detection. Normally,
the time constant filter consists of a 1st order low pass filter (LPF) and 1 to 4 of it
are cascade-connected (equivalent to 6 / 12 / 18 / 24 dB/oct attenuation slope).
Increasing the time constant (TC) and attenuation slope (SLOPE) narrows the
bandwidth and removes more noise, but slows an output response.

1-7

LI5501 / LI5502

1.3 Operating principle

Amplification (DC GAIN)
It is equivalent to sensitivity of this instrument.
After noise is removed by the time constant filter, a signal can be amplified without
being saturated by noise. The phase sensitive detector, time constant filter, and DC
signal amplification are performed in digital operations, so there is no limit to
dynamic reserve caused by DC drift, which becomes a problem in analog method.
Moving average filter (MOV)This filter removes noise by moving average of averaging time. It can be used as asynchronous filter by setting an averaging time to a reference signal period. A rippleof detection output can be significantly reduced, so it is easy to obtain a fast
response by setting a small time constant.
Amplification (EXPAND)
The EXPAND function can amplify an output signal of the moving average filter.
This function is equivalent to EXPAND function of our conventional lock-in
amplifiers.
c) Calculate section (CALCULATE)
Measured values X and Y of a lock-in amplifier are an RMS value of orthogonalphase components.
By operating X and Y, an RMS value and phase of signal can be obtained.
Amplitude ratio and phase difference between two channels can also be obtained*.
*LI5502 only

1-8

LI5501 / LI5502

1.3 Operating principled)Reference signal system (REFERENCE CKT)An internal reference signal that is a sine wave and constant amplitude used by the
PSD is supplied by the internal oscillator.
External reference signal
In principle, a lock-in amplifier performs measurement using an external reference
signal as the reference of the frequency and phase. If the reference signal source isexternal reference, the internal oscillator generates the sine wave synchronizedwith the external reference signal using a Phase Locked Loop (PLL).
Internal oscillator
If the reference signal source is internal reference, the internal oscillator oscillates asignal at a designated frequency. The internal oscillator uses a direct digitalsynthesis method so the frequency is stabilized immediately. A signal of the internal
oscillator is output as a sine wave or TTL-level square wave.
Also, a signal synchronized with external reference signal can be output.
If the amplitude of the internal oscillator is set to zero, interference from reference
signal to measured signal can be reduced, which is often a problem in especially athigh frequencies.
The internal oscillator has a function to generate a harmonic (harmonic,
subharmonic, and fractional harmonic) signal. For example, this function can
generate reference signals of two different frequencies, which enables measurementof a fundamental and a harmonic wave.
External 10 MHz synchronization
If a reference frequency for frequency synthesis is applied to the 10MHz IN terminalfrom an external source, the internal oscillator generates the reference signal
synchronized with that external 10 MHz frequency. Therefore, measurement can be
performed without applying an external reference signal. Not only the reference
signal frequency but also the signal sampling rate, output update rate, and rate forrecording to the data memory by the internal timer are also synchronized with theexternal 10MHz frequency.

1-9

LI5501 / LI5502

1.3 Operating principle(Blank)1-10

LI5501 / LI5502

2． Preparation before use

2.1 Inspection .............................................................2-2
2.2 Installation ............................................................2-3
2.2.1 General cautions ......................................................... 2-3
2.2.2 Installation environment .............................................. 2-3
2.2.3 Mounting ..................................................................... 2-5

2.3 Grounding and power connections .......................2-6
2.4 Firmware update ..................................................2-7
2.5 Calibration ............................................................2-7

2-1

LI5501 / LI5502

2.1 Inspection

2.1

Inspection◼ Safety check
Before using the LI5501 / LI5502, read the “Safety Precautions” section at the beginningof this manual and perform the safety checks described there.
Before connecting the instrument to a power supply, read “2.3 Grounding and power
connections” and perform all safety checks fully.
◼ Unpacking
Firstly, check for any damage that may have occurred during transportation.
After unpacking, make sure that the contents listed in “Table 2-1 Packing list” aresupplied.
Table 2-1 Packing list
Main unit (including the metal fittings) ··································· 1！ WARNING

Precision electronic components are mounted in this instrument. Do not remove thecover.
The interior of this instrument should not be inspected by anyone other than service
technicians who are trained to avoid hazards.

◼ Related documents
The following documents are available on our web site(https://www.nfcorp.co.jp/index.html).
⚫ LI5501 / LI5502 Instruction manualThis instruction manual⚫ Sample programs
Programs written in LabVIEW that can control the LI5501 / LI5502

2-2

LI5501 / LI5502

2.2 Installation

2.2

Installation

2.2.1 General cautions！ CAUTION

Attention should be given to the following item to reduce the possibility of damage
to the LI5501 / LI5502.
 Because the instrument is small and lightweight, if it is moved while connected toother devices by cables, it may fall.
It must be placed on a flat and wide table or the like, being careful of theconnections.

2.2.2 Installation environment Place the instrument in a location that satisfies the following conditions.
Operation:

0 to +50 °C, 5 to 85 %RH(absolute humidity is 1 to 25g/m3, non-condensing)
Altitude of 2000 m or less

Storage:−10 to +60 °C, 5 to 95 %RH(absolute humidity is 1 to 29g/m3, non-condensing)
Altitude of 2000 m or less

 Avoid using the instrument in environments where there is strong radio-frequency
electromagnetic radiation. Using the instrument in such environments may result in
temporary fluctuations in measured values.
！ CAUTION

Avoid installation in the following locations.
 Where there is flammable gases
There is a risk of explosioin. Never install or use it in such a location.
 Outdoors, where exposed to direct sunlight, or near fire or a heat source
The performance may not be satisfied, or a failure may occur.
 Where there are corrosive gases and vapor, a lot of dust and particles, salty air
and oily smoke, and metal powder, etc.
Corrosion, a malfunction or failure may occur.
 Where there is a lot of vibration
A malfunction or failiure may occur.
 Near an electromagnetic field source, high-voltage equipment, power line, or
pulse noise source
A malfunction may occur.

2-3

LI5501 / LI5502

2.2 Installation

Signal cables should be placed away from power cords of other equipment that may
produce inductive noise. Failure to do so may result in instrument malfunction or ameasurement error.
Warm up the instrument for at least 20 minutes before use for accurate measurement.

2-4

LI5501 / LI5502

2.2 Installation

2.2.3 Mounting
Removable metal fittings are provided for this instrument.
When the fittings are removed, rubber feet on the bottom are available.
When installing this instrument in your equipment, it is recommended to screw thefittings to it.
For instrument dimensions → Refer to “9.7 External dimensions”
Metal fittings

Symmetric shape withrespect to the other side
(excluding intake holes)

Rubberfoot

Four M4 x 8mm
screws！ CAUTION Use 8 mm long screws to attach the metal fittings to the instrument.
The internal structure may be damaged if screws longer than 8 mm are used.
 The equipment to be installed in this instrument should have sufficient ventilation
holes or be air-cooled with cooling fans.
If the ambient temperature exceeds the specification or the intake and exhaustholes are blocked when the equipped FAN is used, the performance of the
instrument may decrease or it may be damaged.

2-5

LI5501 / LI5502

2.3 Grounding and power connections

2.3

Grounding and power connections◼ Grounding！ WARNINGThe USB and LAN connector shells are connected to the instrument enclosure.
Applying a voltage of 42 Vpk (DC + ACpeak) or more to the terminals may damage
the instrument.
When using the instrument, ground a power supply and take your own precautions
against electric shock.

◼ Power supply specifications
Power supply voltage range:± 14 to 16 VDC

Current consumption:+400 mA / −110 mA (LI5501)+480 mA / −120 mA (LI5502)
initial settings, no input siganls, and no loads
It is recommended to use a power supply with about
twice the current capacity considering at power-on
and overload conditions.

Power connector:

Equivalent to DELC-J9PAF-20L9 (JAE)Pin assignment:

See below.
−15V

+15V

1

5

2
1
6

9

COM

！ CAUTION• Connect to a power supply paying attention to the voltage range and polarity of it.
• The positive and negative power supplies must start up at approximately thesame time. It is recommended to use a dual tracking power supply.
• The instrument does not work with a single power supply (+30 V / GND).
Be sure to use a dual power supply (+15 V / GND / −15 V).
• Do not supply power to any pins other than the power supply pins.

2-6

LI5501 / LI5502

2.4 Firmware update◼ Recommended power supply
Fluctuations in power supply voltage may affect measured values.
For accurate measurement of minute signals, use a DC power supply with excellent
stability and noise performance.
The recommended DC power supplies are shown below.
・NND30-1515 (TDK Lambda)
・TC-15 (Japan Stabilizer Industry)

2.4

Firmware update

How to check the firmware version → Refer to “8.4 Checking the version number”.
For the latest firmware version and firmware update procedure, please contact the NF
Corporation or its authorized agent or visit our web site(https://www.nfcorp.co.jp/index.html).
Please check the contents of the update and if necessary, update the firmware version.

2.5

Calibration

This instrument is designed to be installed in equipment. It is recmmended to calibrate theinstrument while it is installed in the equipment.
However, perform the unit test described in “8.6 Calibration” at least once a year although
the appropriate calibration interval depends on how often the instrument is used and theconditions under which it is used.
Also, when the instrument is used for important measurement or tests, it is recommended
that the same performance test be performed immediately before the measurement or
tests.
If the instrument fails to satisfy the specifications in the performance test, the NF
Corporation will make adjustments or calibrate the instrument to restore performance.
If an adjustment or calibration is required, please contact the NF Corporation or its
authorized agent. This adjustment and calibration is available for a fee.

2-7

LI5501 / LI5502

2.5 Calibration(Blank)2-8LI5501 / LI5502

3． Names of each part3.1 Names and functions of each part ........................3-2
3.1.1 Top side....................................................................... 3-2
3.1.2 Rear side..................................................................... 3-3

3.2 I/O connectors ......................................................3-4
3.2.1 Signal input connectors .............................................. 3-5
3.2.2 Reference signal I/O connectors ................................ 3-6
3.2.3 Analog data output connectors ................................... 3-7
3.2.4 The other input connector ........................................... 3-7
3.2.5 Power supply connector ............................................. 3-8

3.3 Power-on ..............................................................3-9
3.3.1 Confirmation before power-on .................................... 3-9
3.3.2 Power-on..................................................................... 3-9

3-1

LI5501 / LI5502

3.1 Names and functions of each part

3.1

Names and functions of each part

This section describes the names and functions of each part of the LI5502.

3.1.1 Top side
10MHz Input Connector
To synchronize the frequency of theinternal oscillator with other instruments,
give them the same 10 MHz reference
signal.

USB Connector

LAN Connector

For remote control

For remote control

Power supply
connector
Connector for power
supply± 15 VDC

Signal Input Connectors

Reference signal system

Data output connectors

A IN and B IN
(B IN is only LI5502.)
DC to 1.05 MHz
Zin: 1 MΩ

REF IN
External reference signal input connector
DC (9.5 mHz) to 1.05 MHz
Sine wave 0.4 to 6 Vp-p or TTL
OSC OUT Internal oscillator output connector
9.5 mHz to 1.05 MHz
Sine wave 0 to 1 Vrms or TTL

DATA1 and DATA2
Voltage output corresponding
to the measured value

Figure 3-1 Top side

3-2

LI5501 / LI5502

3.1 Names and functions of each part3.1.2 Rear side

SEL Switch

MODE Switch

Select USB or LAN interface
for remote control.

Settings can be saved.

STATUS
LEDs indicate status of the instrument
UNLOCK
CONDITION

A AC OVLDB AC OVLDEXT CLKCOMM ERRB DC OVLDA DC OVLD

Figure 3-2 Rear side
◼ Status indication
The table below describes the contents of the status LEDs.
Status LED

Color

CONDITION

Green

EXT-CLKGreenUNLOCK

OrangeCOMM ERR

OrangeA AC OVLD

OrangeA DC OVLD

OrangeB AC OVLD(only LI5502)
B DC OVLD(only LI5502)

OrangeOrangeDescription
Lights up when normal operation
Blinks when the calibration information is lost and the specifications
cannot be maintained due to some trouble
When it blinks, please contact the NF Corporation or its authorized
agent as it is malfunction.
The followings applies only when the external 10 MHz
synchronization is enabled.
Lights up when synchronized with an external reference signal
Blinks when not synchronized with an external reference signal
Out of synchronization
There are possibilities that a reference signal is not input, thereference signal settings are not appropriate, the signal level is low,or the frequency of it is out of range.
A communication error
Overflowed the FIFO buffer when transmitting data
Saturates a signal on A IN side before the PSD
Confirm the input signal amplitude.
Saturates a signal on A IN side after the PSD
Adjusts the time constant filter settings and voltage sensitivity.
Saturates a signal on B IN side before the PSD
Confirms the input signal amplitude.
Saturates a signal on B IN side after the PSD
Adjusts the time constant filter settings and voltage sensitivity.

3-3

LI5501 / LI5502

3.2 I/O connectors

3.2

I/O connectors！ WARNING

To avoid an electric shock, ensure that a voltage exceeding 42 Vpk (DC + AC peak)must not be applied between the outer or inner conductor of the BNC connectors
and the enclosure.
Similarly, a voltage exceeding 42 Vpk (DC + AC peak) must not be applied between
the 10 MHz input connector and other BNC connectors.
If doing so, the internal voltage limiters will become active and try to limit thatvoltage. However, if that voltage is too large, there is a risk of electrical shock.

！ CAUTION

Do not apply a voltage exceeding the maximum input range to the input
connectors. Doing so may damage the instrument.

！ CAUTION

Do not apply a voltage to the output connectors. Doing so may damage theinstrument.

3-4

LI5501 / LI5502

3.2 I/O connectors

3.2.1 Signal input connectors
1) Signal input (A IN and B IN*)
The signal input connectors A IN and B IN* are described below.
*LI5502 only
⚫ Input impedance

1 MΩ (nominal value)
20 pF in parallel (supplementary value)⚫ Maximum input voltage (linear operating range)±5V⚫ Non-destructive maximum input voltage± 10 V+10V-10V

A IN, B IN

1M

+

－
-10V

+10V

2) Signal ground
The resistor is inserted between the signal ground and the internal ground (reference
signal input ground, etc.).
The voltage between them is limited to ±1 V.
⚫ Floating voltage (allowable voltage to enclosure)± 1 Vpk (DC＋AC)⚫ Impedance between signal ground and enclosure
22 Ω (nominal value)
22

Internal ground

Signal ground± 1Vpk！ CAUTION

If a voltage exceeding 1.0 V is applied between the signal ground and the internal
ground, a large current will flow and damage an internal circuit.

3-5

LI5501 / LI5502

3.2 I/O connectors

3.2.2 Reference signal I/O connectors
1) Reference signal input (REF IN)
The reference signal input connectors REF IN are described below.
⚫ Input impedance

1 MΩ (nominal value)
20 pF in parallel (supplementary value)⚫ Input voltage range

SINE

0.4 V to 6 Vp-p

TTL

0 to 5 V (low level 0.8 V or less,high level 2.6 V or more)⚫ Non-destructive maximum input voltage± 10 V+10V+

1M

REF IN-10V

2) Oscillator output (OSC OUT)
A sine wave or a TTL-level square wave synchronized with the internal oscillator is
output from the OSC OUT connector.
When the reference signal source is external, the output signal is synchronized with theexternal reference signal.
⚫ Output voltage range

SINE

1 Vrms ± 5 VDC

TTL

0 to 3 V (nominal value)⚫ Maximum output current± 15 mA⚫ Output impedance

53 Ω (nominal value)

+15V
28

-15V

25

OSC OUTOVER Voltage
Detector！ CAUTION

Do not apply a voltage exceeding the maximum input voltage range to REF IN.
There is a limit of output current at the OSC OUT terminal.
If an exceeding voltage is applied to the OSC OUT terminal, an overvoltage will be
detected and an internal circuit will be disconnected.
After the overvoltage is removed, the disconnection will be restored automatically.
The non-destructive maximum input voltage of the OSC OUT terminal is ± 15 V
(noiminal value).

3-6

LI5501 / LI5502

3.2 I/O connectors

3.2.3 Analog data output connectors
1) Measured value output (DATA1 and DATA2)
The voltage proportional to the measured value such as R, X, and Y is output.
⚫ Output voltage range± 12 V (no load)⚫ Maximum output current± 10 mA⚫ Output impedance

440 Ω (nominal value)

+15V

+15V
220

220

DATA1 / 2

-15V

-15V

3.2.4 The other input connector
1) External 10MHz synchronization (10MHz IN)⚫ Input impedanceApproximately 500 Ω, AC-coupling⚫ Signal level

0.5 to 5 Vp-p

⚫ Non-destructive maximum input voltage
10 Vp-p⚫ Withstand voltage (allowable voltage to enclosure)± 42 Vpk (DC + ACpeak)
2000p
10MHz IN

± 42Vpk

1M

100k

EXT
REF
CKT

3-7

LI5501 / LI5502

3.2 I/O connectors

3.2.5 Power supply connector
1) Power supply input (POWER)
The power supply connector is equivalent to DELC-J9PAF-20L9 (JAE).
It is recommended to use a power supply with about twice the current capacity
considering at power-on and overload conditions.
⚫ Voltage range± 14 to 16 VDC⚫ Current consumption

Approximately +400 mA / -110 mA (LI5501)
Approximately +480 mA / -120 mA (LI5502)
initial settings, no input signals, and no loads

-15V

+15V

TRG

+15V
5

2
1
6

COM

± 42Vpk
COM−15V (internal circuit)

-15V

9

1M

1

+15V (internal circuit)

SHELL

TGRT

2) External trigger inputThis input is to start recording measurement data to the internal data buffer.
⚫ Input impedance

10 kΩ (nominal value)⚫ Signal level

TTL (low level 0.8 V or less, high level 2.6 V or more)⚫ Non-destructive maximum input voltage± 15 V
+3.3V

10k

+3.3V

TRG

CMOS
LOGIC

10k

TGRT
G

！ CAUTION

Applying a voltage exceeding the specified voltage range, incorrect polarity of thepower supply, or wrong connection to terminals may result in failure.

3-8LI5501 / LI5502

3.3 Power-on

3.3

Power-on

3.3.1 Confirmation before power-on
Check the power supply voltage and the pin assignments of the power connector before
power-on.
Refer to “2.3 Grounding and power connections”.

3.3.2 Power-on
The LI5501 / LI5502 have no power switch.
Supply power to the instrument from an external power supply.
A typical connection diagram is shown below.
When the power is turned on, the settings of the configuration memory number
corresponding to the MODE switch number are recalled.
For details → Refer to “6.2 Configuration memory”.

LINE

INPUT

OUTPUTPower supply unit

PC
Typical connection diagram

3-9

LI5501 / LI5502

3.3 Power-on(Blank)3-10

LI5501 / LI5502

4． Basic settings

4.1 Setting items ........................................................4-2
4.1.1 Reference signal settings ........................................... 4-2
4.1.2 Phase shift and harmonics measurement .................. 4-4
4.1.3 Oscillator output .......................................................... 4-6
4.1.4 Analog data outputs .................................................... 4-7
4.1.5 Sensitivity and dynamic reserve ................................. 4-8
4.1.6 Filters ........................................................................4-10
4.1.7 PSD input offset adjustment .....................................4-14

4.2 Initial settings ..................................................... 4-15

4-1

LI5501 / LI5502

4.1 Setting items

4.1

Setting items

This section describes setting items of the LI5501 / LI5502.

4.1.1 Reference signal settings
A reference signal serves as frequency and phase reference.
This section describes how to select reference signal settings.
1) Reference signal source
Select a reference signal source from below to synchronize with the instrument.
⚫ Reference signal source: RINP (External reference signal)
Input a reference signal to the REF IN terminal.
IOSC (Internal oscillator)
The internal oscillator generates a designated frequency.
2) Waveform of external reference signal
When using an external reference signal, select a edge from below according to the input
waveform.
⚫ Edge:SIN (sine wave, 0.4 to 6 Vp-p,
point where signal crosses 0 V from below to above)
TPOS (square wave, rising edge of TTL-level)
TNEG (square wave, falling edge of TTL-level)

REF IN waveform

SINE

TTL POSVth
0V

0V

TTL NEGHigh level: 2.6V or more
Low level: 0.8V or less

Vth
0V

0°

0°

0°

◼ UNLOCK state
When the reference signal source is set for the external reference signal (RINP) andthe reference signal is not synchronized with the instrument, the LED on the rear
panel will light up and a flag is set in the status register.
In the UNLOCK state, a measured frequency and values do not correspond to those of
the actual signal and fluctuate.
When the instrument cannot synchronize with a reference signal, the frequency,
amplitude, or waveform of the signal may be different from the reference signal
settings. Also, if a reference signal contains a lot of noise or frequency/amplitude
variations, the instrument may be the UNLOCK state.

4-2

LI5501 / LI5502

4.1 Setting items

3) Internal oscillator
The internal oscillator frequency can be set.
This is available when the reference signal source is IOSC (internal oscillator).
⚫ Frequency:

9.5 mHz to 1.05 MHz, 0.1 mHz resolution4) 10MHz IN
The frequency reference source of the instrument can be synchronized with other
instruments (such as function generators) that operate with a 10 MHz frequency
reference source.
However, since the phase do not match, the phase adjustment is required every time theinternal oscillator frequency is changed. Generally, once a signal (oscillation) stops, thephase is shifted, so the phase adjustment is required again.
LI5501 / LI5502
EXT OSC
Frequency

System
Under
Test

A IN

PSD

OSC
OUT
10MHz IN

10MHz
Frequency
source

DATA
OUT

10MHz
REF OUTINT OSC
Frequency(Numerical value)

As a result, by matching the frequency setting of other devices with the internal
oscillator frequency of the instrument, it can be synchronized with other devices even
without inputting a reference signal to the REF IN terminal.
⚫ 10MHz IN:

ON (enabled), OFF (disabled)◼ EXT CLK LED
The table below shows the status of the LED corresponding to the 10 MHz IN setting
and a signal to 10 MHz IN terminal.
10MHz IN setting
ON
ON
OFF

Signal to 10MHz IN terminal
10MHz signal
Signal other than 10MHz or no
signal―――4-3

LED (EXT CLK)ON
Blinking
OFF

LI5501 / LI5502

4.1 Setting items◼ φSYNC function
When the instrument is connected to the 10 MHz REF OUT terminal of our function
generators (WF1973 / 74, WF1947 / 48, WF1967 / 68), the reference phase of theinternal oscillator can be initialized by the φSYNC function of the function generators.
For detials, refer to the instruction manual of the function generators.

4.1.2 Phase shift and harmonics measurement
The phase can be shifted with respect to the reference signal.
A fundamental wave (F), harmonic (n × F), subharmonic (F / m), and fractional harmonic(n × F / m) can be measured with a reference signal frequency “F” as the reference.
1) Phase shift
The phase shift amounts of A/B IN can be set with respect to the reference signal.
⚫ Phase shift amount:−180.000° to +179.999°, 1m° resolution

Basic usage of a lock-in amplifier is to adjust the phase of the reference signal to be
applied to the PSD so that Y output is equal to zero (θ = 0), and then measure theamplitude of the signal at the X output and the phase shift of the signal at the Y output.
PSD
reference signal

SignalPSD
reference
signalY
R

SignalX' = RRθθX

REF IN= PSD reference signal

Y' = 0θ' = 0REF IN

Phase shift amount = 0

Phase shift amount = −θ◼ Automatic phase shift adjustment
By executing this adjustment, the reference signal phase shift amount is set so that
the Y and θ outputs are equal to zero. However, it cannot be executed during the
UNLOCK state.

4-4LI5501 / LI5502

4.1 Setting items

2) Harmonic
The reference signal frequencies of A IN and B IN can be multiplied by “n”.
⚫ Harmonic:

1 to 63 or 0 (integer)

Set “n” to 1 when measuring a fundamental wave. When measuring a fractional
harmonic, the “n” is the numerator.
When the “n” is set to zero, the input signal passes through the PSD.
3) Subharmonic
When the reference signal source is the external reference signal (RINP), the externalreference signal can be divided by “m”.
⚫ Subharmonic:

1 to 64 (integer)

When measuring a fractional harmonic, the “m” is the denominator. This “m” is common
to each PSD and the oscillator output.
The response to the frequency query command (:FREQ?) is the frequency input to the
REF IN terminal diveded by the “m”.
4) Multiplication and phase shift of oscillator output
The output frequency of the OSC OUT terminal can be multiplied by that of thereference signal source. The phase can also be shifted with respect to the reference
signal source.
⚫ Multiplication:

1 to 63 (integer)⚫ Phase:−180.000° to +179.999°, 1m° resolution◼ Note
The frequency range of harmonic, subharmonic, fractional harmonic, and multiplieroscillation output need to be within the synchronizable frequency range.

4-5

LI5501 / LI5502

4.1 Setting items

4.1.3 Oscillator output
The frequency synchronized with the reference signal can be output to the OSC OUT
terminal.
1) Oscillator output state
When the oscillator output is turned on, the AC voltage is output from the OSC OUT
terminal.
When the oscillator output is turned off, the D/A converter for the oscillator output is
stopped and the output amplitude is set to zero.
However, DC offset is always output.
⚫ Output state:

ON (enabled), OFF (disabled)◼ Crosstalk reduction
Crosstalk from the reference signal to the measured signal can be reduced bydisabling the oscillator output.
2) Output waveform selection
The output waveform can be selected from a sine wave or TTL-level square wave.
⚫ Output wave form:

SIN (sine wave), TTL

3) Output amplitude and DC offset
The output amplitude and DC offset can be set only when the output waveform is SIN(sine wave).
⚫ Amplitude:

0 to 1 Vrms, 1 mVrms resolution⚫ DC offset:

0 to ± 5 V, 5 mV resolution

DC offset
Sine wave

0V
Amplitude
1 Vrms max

TTL

3 Vp-p (nominal value)
0V

4-6

LI5501 / LI5502

4.1 Setting items

4.1.4 Analog data outputs
Parameters shown in the table below can be obtained.
ParameterX
YRθDescription
In-phase component (= R cos θ)Quadrature component (= R sin θ)
Signal amplitude (= X2 + Y 2 )Signal phase (= tan −1 Y / X )SignalYRθX
PSD Reference signal

The voltage corresponding to the measured value of designated parameter can be output tothe DATA1 or DATA2 terminal.
⚫ DATA1:

See the below table.

⚫ DATA2:

See the below table.

Parameter
Description
XA
X value on A IN side (Rcosθ)YA
Y value on A IN side (Rsinθ)RA
R value on A IN side (RMS amplitude)θAθ value on A IN side (phase value)
XB
X value on B IN side (Rcosθ)YB
Y value on B IN side (Rsinθ)RB
R value on B IN side (RMS amplitude)θBθ value on B IN side (phase value)
RATIO
Amplitude ratio (RA / RB)
PHASE
Phase difference (θA − θB)
Parameters related to B IN are available only for the LI5502.
◼ Disabling analog data outputs
The DATA1 and DATA2 output terminals can be disabled. Doing so stops the clock signal
to the D/A converter, which reduces noise and is resistant to interference whenmeasuring minute signals.

4-7

LI5501 / LI5502

4.1 Setting items

4.1.5 Sensitivity and dynamic reserve
The dynamic reserve value depends on saturation signal level inside the instrument at a
specific sensitivity (full scale of signal) and noise rejection characteristics of the time
constant filter. In other words, it depends on frequency.
Set the value to the minimum. The higher the DR setting (lower AC GAIN) is set, thelarger the input-referred noise and the drift of measured value will be.
◼ Dynamic reserve for random noise

Sensitivity(full scale ofsignal)Dynamic reserve

Time constantfilterRandom noise (wideband noise) is acceptable until
Signal frequency

Saturation
signallevel

its peak value reaches the saturation signal level
inside the instrument. Even if the RMS values ofsine wave and random noise are equal, the peakvalue of noise is several times larger than that ofsine wave. Set the dynamic reserve considering that0Frequency
deviation

peak value.

1) Dynamic reserve setting
The DR setting corresponds to the gain of the analog circuit before the PSD. This setting
restricts the range of the voltage sensitivity.
⚫ DR setting:

LOW1, LOW2, MED, HIGH

2) Voltage sensitivity
The voltage sensitivity is the DC gain after the time constant filter.
⚫ Voltage sensitivity:
DR
LOW1
LOW2
MED
HIGH

See below (1-2-5 sequence).
AC GAIN
100x
10x
1x
0.2x

Range
10 nVrms to
10 mVrms
100 nVrms to 100 mVrms
1 μVrms to
1 Vrms
5 μVrms to
1 Vrms◼ NoteIf the DR setting is changed and the voltage sensitivity is out of range, the sensitivity
may be changed corresponding to the DR setting after the change.

4-8

LI5501 / LI5502

4.1 Setting items◼ Dynamic reserve
The actual dynamic reserve value depends on dynamic reserve setting, voltage
sensitivity, frequency difference between signal and noise, and settings of the time
constant filter.
The values in the table below are nominal values when noise is sufficiently removed by
the time constant filter.
Setting a dynamic reserve greater than 100 dB requires a large time constant setting
and may result in large error in measured value.
DR setting
Voltagesensitivity(A/B IN)
1V
500 mV
200 mV
100 mV
50 mV
20 mV
10 mV
5 mV
2 mV
1 mV
500 μV
200 μV
100 μV
50 μV
20 μV
10 μV
5 μV
2 μV
1 μV
500 nV
200 nV
100 nV
50 nV
20 nV
10 nV

LOW1
AC
DR
gain
dB
dB
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
40
6
40
12
40
20
40
26
40
32
40
40
40
46
40
52
40
60
40
66
40
72
40
80
40
86
40
92
40
100
106
40
112
40
120
40
126
40

LOW2
AC
DR
gain
dB
dB
―――
―――
―――
―――
―――
―――
20
6
20
12
20
20
20
26
20
32
20
40
20
46
20
52
20
60
20
66
20
72
20
80
20
86
20
92
20
100
106
20
112
20
120
20
126
20
―――
―――
―――
―――
―――
―――

4-9

MED
AC
DR
gain
dB
dB
0
6
0
12
0
20
0
26
0
32
0
40
0
46
0
52
0
60
0
66
0
72
0
80
0
86
0
92
0
100
106
0
112
0
120
0
126
0
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――

HIGH
AC
DR
gain
dB
dB
-14
20
-14
26
-14
32
-14
40
-14
46
-14
52
-14
60
-14
66
-14
72
-14
80
-14
86
-14
92
-14
100
106
-14
112
-14
120
-14
126
-14
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――
―――

LI5501 / LI5502

4.1 Setting items

4.1.6 Filters
This section describes the time constant filter, DC offset, moving average filter, andEXPAND function.
1) Time constant filter
The time constant of the time constant filter can be set.
⚫ Time constant:

1 μs to 1 ks, 1-2-5 sequence2) Attenuation slope
The attenuation slope of the time constant filter can be set.
⚫ Attenuation slope:

6 / 12 / 18 / 24 dB/oct◼ Time constant filter
The characteristics of the time constant filter (TC) are those of cascade-connected
first-order lowpass filter (cutoff frequency: fc). The attenuation slope per stage is 6
dB/oct (20 dB/dec). This means that in the transition band, doubling the frequency
results in half attenuation (a ten-fold increase in frequency results in one-tenthattenuation).
By cascade-connecting 1 to 4 stages of this filter, the attenuation slope of 6 to 24
dB/oct (20 to 80 dB/dec) can be obtained.
6dB/oct
PSD

First-order low pass filter

12dB/oct
18dB/oct

Reference
signal24dB/octCascade-connected filters

4-10

LI5501 / LI5502

4.1 Setting itemsa) Frequency response
Normalized frequency =|Frequency difference from reference signal| / cutoff frequency (fc)
fc = 1 / (2πT)
Here, T indicates a time constant.
6dB/oct

-20
-30
-40
-50
-60
-70
-80

Gain, Amplitude[dB] dB
Gain 利得

0-1024dB/oct
0.1

1

10

Normalized
frequency
正規化周波数

TC
Small
TC
Large

0
(Signal)

Noise
1F
2F
Ripples
F: Signal frequencyb) Equivalent noise bandwidth BN
3dB bandwidth
Equivalent noise bandwidth

Sensitivity to white noise is represented by equivalentnoise bandwidth. The bandwidth of an ideal filter
where sensitivity to noise (in other words, an RMS
value of output noise) is equal to that of an actual
filter is called the equivalent noise bandwidth of thatfilter.
Actual filter

Ideal filter

The equivalent noise bandwidth of this instrument BN
is twice that of a low pass filter determined by thetime constant T and attenuation slope. BN isrepresented by the following expression.

BN6 =

1
3
5
1
， B N 12 =， BN 18 =， BN 24 =
2T
16T
32T
4T

corresponding to 6, 12, 18, and 24 dB/oct respectively
The RMS noise value Vm included in the output (measured value) can be obtainedusing the following expression.

Vm = Vn  BN
Here, Vn indicates the noise density of the input and BN indicates the equivalent noise
bandwidth.

4-11

LI5501 / LI5502

4.1 Setting itemsc) -3dB bandwidth B3dB

B3dB =

m

2 − 1 ( T )Here, T indicates the time constant, and m is equal to 1, 2, 3, or 4 (corresponding to 6,
12, 18, or 24 dB/oct respectively).
d) Step response time
A response y(t) to applying a step signal to low pass filter after phase sensitive
detection is represented by the following expression.

m − Tt
t n−1
e
 n−1
 n=1 T (n − 1)!y (0 ) = 0 , y(t ) = 1 − However, t is greater than 0.

Here, T indicates the time constant, and m is equal to 1, 2, 3, or 4 (corresponding to 6,
12, 18, or 24 dB/oct respectively).
Step response time

90 %
99 %
99.9 %

6
2.3 T
4.6 T
6.9 T

SLOPE (dB/oct)
12
18
24
3.9 T
5.3 T
6.7 T
10.0 T
6.6 T
8.4 T
9.2 T 11.2 T 13.1 T

This is the case of analog filter. Since the

6dB/oct

1.0

正規化振幅
amplitude
Normalized

Response

Step response waveform

0.8
24dB/oct

0.6
0.4
0.2
0.0
0

instrument realizes this filter by digital

2

4
6
8
10
Time
(multipleof T)
時間(Tの倍数)

12

processing, the filter characteristics when
the time constant is small differ slightly from the above.

4-12

LI5501 / LI5502

4.1 Setting items

3) Offset function
An offset can be set in the X-axis and Y-axis for signal amplified by the voltage
sensitivity (DC GAIN).
By moving a measured value near zero using the offset function, changes in the value
can be magnified and small changes of it can be read.
⚫ X-axis offset:± 120 % (relative to full scale)⚫ Y-axis offset:± 120 % (relative to full scale)

ExpandY OFFSET

Signal

Y
R
θ

Y'
R'

R

θ'

θ
X

X'

X OFFSETPSD reference signal

4) Moving average filter
The averaging time of the moving average filter can be set.
⚫ Averaging time:

1 μs to 100 s, 1-2-5 sequence
AUTO (Inverse of reference signal frequency is set.)
OFF (Disabled)

When the time constant is reduced in the TC filter, integer multiple ripples of thereference signal frequency are difficult to attenuate. In this case, the output response
will slow at low frequency because the time constant must be large even if noise is small.
In such case, if the moving average filter is enabled, the ripple generated at integer
multiples of the reference signal frequency can be attenuated.
The moving average filter is connected after the TC filter.
Frequency response of moving average filter

Diagram of filters

Gain, Amplitude(Averaging interval equals to 1 cycle)
PSD

Reference
signal

1F
2F
RippleF: Signal frequency

4-13

Moving average filter

Cascade-connected
time constant filters

LI5501 / LI5502

4.1 Setting items

5) EXPAND function
The EXPAND value can be set to expand a signal after the MOV filter.
X, Y, and R values are commonly expanded. θ value is not affected.
⚫ EXPAND:

1 to 1000 [times], 1-2-5 sequence recommended

4.1.7 PSD input offset adjustment
The instrument has a function to cancel a DC offset of the PSD input.
If a DC component is included in the PSD input, a 1F ripple that is equal to themeasurement frequency F occurs in the PSD output. A large time constant is required toremove the 1F ripple and an output response slows.
If a fast response is needed at high frequencies, it is recommended to perform the PSD
input offset adjustment.
At low frequencies, it is effective to use the MOV filter simultaneously.
DC

PSD

TC Filter

IN

REF
0

1F

2F

Frequency

Before the adjustment, short-circuit input terminals (A/B IN).
Execute the PSD input offset adjustment command to start the adjustment.
The adjustment takes about 10 seconds. After adjustment, release short-circuit on the
input terminals.
Executing the command to initialize the PSD input offset will return it to the factory
default settings.
◼ Preparation
The following preparation is needed to execute the PSD input offset adjustment.
• Set the actual operating conditions. When measurement parameters such as the
dynamic reserve are changed after this adjustment, a re-adjustment is required.
• Set input signals to zero.
• Warm up the instrument sufficiently so that a temperature drift after the
adjustment can be reduced.
• Keep the power supply voltage and ambient temperature as constant as possible.

4-14

LI5501 / LI5502

4.2 Initial settings

4.2

Initial settings

The LI5501 / LI5502 will be initialized at the following conditions below.
• When shipped from a factory and the MODE switch is set to “F”
All of the settings are the factory default settings.
• When the system initialization is executed
Settings other than the LAN interface are initialized.
Use the “:SYSTem:RST” command.
• When the initialization is executedContents of the resume memory are initialized.
Use the “*RST” command.
• When there is an abnormality in the resume memory
When the power is on, if there is an abnormality in the resume memory, abnormalparts will be initialized.
The details of the setting items and initial values are shown in “Table 4-1 Setting items
and initial values”.

:SYST:RST*RST

Configuration
memoryResumeTable 4-1 Setting items and initial values

REF IN, INT OSC
SIN+, TTL+, TTL-REF IN
SIN+







Y
Y

Y
Y

9.5 mHz to 1.05000 MHz
OFF, ON

1.00000 kHz
OFF







Y
Y

Y
Y

1 to 64
1 to 63
1 to 63
1 to 63

1
1
1
1











Y
Y
Y
Y

Y
Y
Y
Y

-180.000° to +179.999°-180.000° to +179.999°-180° to +179.999°

0°
0°
0°









Y
Y
Y

Y
Y
Y

OFF, ON
SINE, TTL
0.0 to 1.000 Vrms
0 to ± 5.000 V

OFF
SINE
0.000 Vrms
0 mV











Y
Y
Y
Y

Y
Y
Y
Y

Setting item

Parameter range

Initial value<Reference signal>
Reference signal source
Waveform (EDGE)<Internal oscillator>
Frequency
10MHz IN

<Harmonics>
Common subharmonic
A IN harmonic
B IN harmonic
Oscillator multiplication<Phase adjustment>
A IN phase shift
B IN phase shift
Oscillator phase shift<Oscillator output>
Output state
Waveform
Amplitude
DC offset

4-15

LI5501 / LI5502

4.2 Initial settings*RST

Configuration
memoryResumeSetting item

:SYST:RST

Table 4-1 Setting items and initial values





RA





Y

Y

θA





Y

Y

LOW1 / LOW2 / MED / HIGH
LOW1 / LOW2 / MED / HIGH

MED
MED







Y
Y

Y
Y

10 nV to 1 V
10 nV to 1 V

1V
1V







Y
Y

Y
Y

1 μs to 10 ks (1-2-5)
1 μs to 10 ks (1-2-5)
6 / 12 / 18 / 24 dB/oct
6 / 12 / 18 / 24 dB/oct

100 ms
100 ms











Y
Y
Y
Y

Y
Y
Y
Y

± 120.000 %± 120.000 %0%0%± 120.000 %± 120.000 %

0%
0%











Y
Y
Y
Y

Y
Y
Y
Y

1 μs to 100 s (1-2-5), AUTO, OFF
1 μs to 100 s (1-2-5), AUTO, OFF

OFF
OFF







Y
Y

Y
Y

1 to 1000
1 to 1000

1
1







Y
Y

Y
Y

Default, Automatic adjustment

Default





Y

Y

STATUS, FREQ-H, FREQ-L,
XA, YA, RA, θA,
XB, YB, RB, θB,
RATIO, PHASE
up to 7 words from aboveRA, θAYYParameter range

Initial value<Analog data output>
XA, YA, RA, θA,
XB, YB, RB, θB,
G, P
XA, YA, RA, θA,
XB, YB, RB, θB,
G, P

DATA1
DATA2

<Dynamic reserve>
A IN DR
B IN DR<Voltage sensitivity>
A IN sensitivity
B IN sensitivity<Time constant filter>
A IN time constant
B IN time constant
A IN attenuation slope
B IN attenuation slope

24 dB/oct
24 dB/oct<DC offset>
A IN X offset range
A IN Y offset range
B IN X offset range
B IN Y offset range<Moving average filter>
A IN averaging time
B IN averaging time

<EXPAND multiplier>
A IN EXPAND multiplier
B IN EXPAND multiplier<PSD input offset >Offset amount<Communication>
Measurement data
parameters

4-16

LI5501 / LI5502

4.2 Initial settings:SYST:RST*RST

Configuration
memoryResumeTable 4-1 Setting items and initial values

0.4 μs to 26.2 ms
1 to 65536
BUS, EXT
0 to 1.67 s

0.8 μs65536
BUS
104 ms











Y
Y
Y
Y

Y
Y
Y
Y

0.0.0.0 to 255.255.255.255
0.0.0.0 to 255.255.255.255
0.0.0.0 to 255.255.255.255

192.168.0.2
255.255.255.0
0.0.0.0

N
N
N

N
N
N

Y
Y
Y

Y
Y
Y

ON, OFF, AUTO

AUTO





Y

Y

－

Initial values



N

－

－

Setting item

Parameter range

Initial value<Measurement data buffer>
Sampling interval
Buffer size
Trigger source
Trigger delay time

<Interface>
LAN IP address
LAN subnet mask
LAN default gateway<FAN control>
FAN control<Configuration memory>
Contents◼ Notes
Initial values

Factory default settings:SYST:RST

When the :SYSTem:RST command is executed*RST

When the *RST command is executedSame as left (initial value)N

Has no function (not changed)

Y

Has a function (setting stored)－

Not applicable

The followings are not stored in the resume memory.
・Measurement data stored in the measurement data buffer・Latest measurement data
The commands with respect to B IN and the measurement data parameters (XB, YB, RB,
θB, RATIO, and PHASE) are only applicable to the LI5502.

4-17

LI5501 / LI5502

4.2 Initial settings(Blank)4-18

LI5501 / LI5502

5． Remote control

5.1 Preparation before use .........................................5-2
5.1.1 Selection of the remote control interface .................... 5-2
5.1.2 USB overview ............................................................. 5-2
5.1.3 LAN overview .............................................................. 5-3
5.1.4 Precautions of communication ................................... 5-4

5.2 List of commands and command tree ..................5-5
5.2.1 List of commands........................................................ 5-5
5.2.2 Command tree ............................................................ 5-8

5.3 Commands ......................................................... 5-10
5.3.1 Overview ...................................................................5-10
5.3.2 Sequential commands ..............................................5-20
5.3.3 Commands description .............................................5-21

5.4 Status system ..................................................... 5-39
5.4.1 Overview of status system ........................................5-39
5.4.2 Status byte ................................................................ 5-40
5.4.3 Standard event status ...............................................5-41
5.4.4 Operation status .......................................................5-43
5.4.5 Questionable status ..................................................5-46

5.5 Error messages .................................................. 5-49

5-1

LI5501 / LI5502

5.1 Preparation before use

5.1

Preparation before use

The LI5501 / LI5502 can be controlled remotely via USB or LAN interface.
By sending messages from a controller (personal computer for control), it is possible tochange settings, check current settings, and obtain measurement data.

5.1.1 Selection of the remote control interface
Select the USB or LAN interface by flipping the SEL switch on the rear panel.
The interface connectors are located on the rear panel of the LI5501 / LI5502.
It is not possible to use both of the two interfaces at the same time.

5.1.2 USB overview
5.1.2.1 Preparation of controller
To use the USB interface, prepare a controller equipped with a USB interface.
Install the USBCDC (Universal Serial Bus Communication Device Class) driver on thecontroller.
◼ USBCDC driver
The USBCDC driver is required before Windows10.
It is available on our web site (https://www.nfcorp.co.jp).
5.1.2.2 Connections and cautions
The LI5501 / LI5502 should be connected directly to the USB connector of the computer by
a commercial USB cable. The instrument may not operate correctly if the connection ismade via a USB hub.
5.1.2.3 Confirmation of connection
If the instrument-specific information can be obtained, the connection has been madecorrectly.
Vendor ID = 0D4A (hexadecimal notation): The number indicates the NF Corporation.
Product ID = 0078 (hexadecimal notation): The number indicates the product number for
LI5501.
Product ID = 0079 (hexadecimal notation): The number indicates the product number for
LI5502.
Serial Number = 1234567 (example): A 7-digit serial number is specific to the instrument.

5-2

LI5501 / LI5502

5.1 Preparation before use◼ Message terminator
A set of commands and responses must end with a terminator that indicates the end of
the message.
The response message terminator sent by the LI5501 / LI5502 is always LF.
The program message terminator received by the LI5501 / LI5502 is always LF.

5.1.3 LAN overview
5.1.3.1 Preparation of controller
To use the LAN interface, prepare a controller equipped with a LAN interface (a personal
computer for control). The LI5501 / LI5502 can communicate by using the TCP/IP protocol.
5.1.3.2 Connections
The LI5501 / LI5502 can distinguish a straight and a crossover cable, so either type of cable
can be used.
5.1.3.3 Settings of the LI5501 / LI5502
Configure the following settings when the instrument is connected via the USB interface.
◼ IP address
In the IP (Internet Protocol), an address that identifies an instrument is set (logicaladdress). The range of addresses from 192.168.0.0 to 192.168.255.255 is for private IP
addresses that can be used freely within a small-scale local network (class C).
◼ Subnet mask
A subnet mask is set to separate the IP addresses of a higher-level network and those oflower-level network.
◼ Default gateway
When an instrument accesses an external network, the IP address of the gateway(repeater) to be used will be set implicitly.
◼ Port number
The specific port number is used when the LI5501 / LI5502 communicates using the TCP
protocol.
The number is 5025 (decimal notation) and cannot be changed.
◼ MAC addressThis indicates an instrument-specific address (physical address). It cannot be changed.
For example, when a serial number is 1234567, the MAC addressis ”00:14:CE:12:D6:87”.
”00:14:CE” is fixed.
1234567 (decimal notation) → 12D687 (hexadecimal notation)

5-3

LI5501 / LI5502

5.1 Preparation before use◼ Message terminator
A set of commands and responses must end with a terminator that indicates the end of
the message.
The response message terminator sent by the LI5501 / LI5502 is always LF.
The program message terminator received by the LI5501 / LI5502 is always LF.

5.1.4 Precautions of communication◼ Input buffer Commands that have been sent are temporarily stored in the input buffer and thenthey are interpreted and executed in sequence. The input buffer capacity is 1024
bytes. Even if program messages exceed that size, these messages will be interpreted
and executed in sequence.
 If an invalid command is encountered during interpretation and execution, an error
will occur and none of the subsequent commands up to the program message
terminator will be executed.
◼ Output buffer The output buffer capacity is 1024 bytes.
 If the maximum capacity is exceeded, the output buffer will be cleared and the query
error bit of the standard event status register is set to “1”. Subsequently, commandinterpretation and execution proceeds in the normal manner, but all generated
response messages are discarded up to the program message terminator.
◼ Error queue The queue can hold up to 16 error messages.
 If there are more than 17 error messages, the 16th message will return “Queue
overflow” and subsequent error messages will be discarded. The error messages up to
the 15th message will be retained.
◼ Program message terminator• When commands are sent from the controller, be sure to append the program message
terminator, which is either LF (Line Feed, 0x0A hex) or CRLF (Carriage Return, 0x0D
hex + Line Feed, 0x0A hex) to the end of the message.

5-4

LI5501 / LI5502

5.2 List of commands and command tree

5.2

List of commands and command tree

5.2.1 List of commands
The remote control commands and subsystem commands for the LI5501 / LI5502 are listed
in the “Table 5-1 Common commands” and “Table 5-2 Subsystem commands”.
The descriptions here are in short-form format, which omits all optional keywords. For the
long-form format and the parameter format of the commands, refer to pages listed in thecolumn of “Details”.
Supplement: Commands that perform a query end with a question mark (?). In thesetables, the queries are omitted for commands that can both set and query aparameter.
The rows of “R/W” in the tables indicate whether there are functions forquerying (R) and setting (W). The rows of “*RST” indicate whether thefunction can be initialized by the “*RST” command.
Table 5-1 Common commands
Command
*CLS
*ESE
*ESR?
*IDN?
*OPC
*RCL
*RST
*SAV
*SRE
*STB?
*TST?
*WAI

Function

R/W

*RST

Details

Clears status register and error queueStandard event status enable register
Queries standard event status register
Queries instrument-specific information
Notification that all previous commands have ended
Reads from the configuration memory
Initializes configuration
Saves to the configuration memory
Service request enable register
Queries status byte register
Queries results of the self-diagnostic test
Waits for execution of commands and queries

W
R/W
R
R
R/W
W
W
W
R/W
R
R
W

－
－
－
－
－
－
－
－
－
－
－
－

P5-21
P5-21
P5-21
P5-21
P5-21
P5-22
P5-22
P5-22
P5-22
P5-22
P5-22
P5-22

R/W

*RST

Details

W

－

P5-23

Sets DATA1 output parameter
Sets A IN EXPAND multiplier
Sets A IN offset value for X output

R/W
R/W
R/W

✓
✓
✓

P5-23
P5-23
P5-23

Sets DATA2 output parameter
Sets A IN offset value for Y output

R/W
R/W

✓
✓

P5-24
P5-24

Sets B IN EXPAND multiplier
Sets B IN offset value for X output

R/W
R/W

✓
✓

P5-24
P5-24

Sets B IN offset value for Y output

R/W

✓

P5-25

Table 5-2 Subsystem commands
Command
ABORt subsystem:ABORtCALCulate subsystem:CALC:FORM:CALC:MULT:CALC:OFFS
CALCulate2 subsystem:CALC2:FORM:CALC2:OFFS
CALCulate3 subsystem:CALC3:MULT:CALC3:OFFS
CALCulate4 subsystem:CALC4:OFFS

Function
Aborts recording of measurement data

5-5LI5501 / LI5502

5.2 List of commands and command tree

Command
DATA subsystem:DATA:COUN?
:DATA:DATA?
:DATA:DEL:DATA:FEED:DATA:FEED:CONT:DATA:POIN:DATA:PER
FETCh subsystem:FETC?
INITiate subsystem:INIT
INPut1 subsystem:INP:OFFS:AUTO:ONCE:INP:OFFS:RST
INPut2 subsystem:INP2:OFFS:AUTO:ONCE:INP2:OFFS:RST
INPut3 subsystem:INP3:TYPE
MEMory subsystem:MEM:STAT:DEL
OUTPut subsystem:OUTP
OUTPut2 subsystem:OUTP2
ROUTe subsystem:ROUT
SENSe subsystem:DRES:DRES2:FREQ?
:FREQ:MULT:FREQ:SMUL:FREQ2:MULT:FILT:SLOP:FILT:TCON:FILT:MOV:FILT2:SLOP:FILT2:TCON:FILT2:MOV:PHAS:PHAS:AUTO:ONCE:PHAS2:PHAS2:AUTO:ONCE:ROSC:SOUR:VOLT:AC:RANG:VOLT2:AC:RANG

Function

R/W

*RST

Details

Queries the number of data sampling points
Queries measurement values
Clears measurement data buffer
Sets data parameters to record
Whether to record measurement data
Sets measurement data buffer size
Sets recording interval

R
R
W
R/W
R/W
R/W
R/W

✓
✓
✓
✓
✓
✓
✓

P5-25
P5-25
P5-25
P5-26
P5-26
P5-26
P5-27

Queries latest measurement data

R

✓

P5-27

Starts triggering system

W

✓

P5-27

Executes PSD input offset adjustment (A IN)
Disables PSD input offset adjustment (A IN)

W
W

✓
✓

P5-27
P5-27

Executes PSD input offset adjustment (B IN)
Disables PSD input offset adjustment (B IN)

W
W

✓
✓

P5-27
P5-27

R/W

✓

P5-28

Clears contents of designated memory

W

－

P5-28

Sets output state of DATA1 terminal

R/W

✓

P5-28

Sets output state of DATA2 terminal

R/W

✓

P5-28

Selects reference signal source

R/W

✓

P5-28

Sets A IN dynamic reserve
Sets B IN dynamic reserve
Queries frequency
Sets harmonic order “n” (A IN)
Sets subharmonic order “m” (A/B IN)
Sets harmonic order “n” (B IN)
Sets attenuation slope of TC filter (A IN)
Sets time constant of TC filter (A IN)
Sets averaging time of MOV filter (A IN)
Sets attenuation slope of TC filter (B IN)
Sets time constant of TC filter (B IN)
Sets averaging time of MOV filter (B IN)
Sets phase shift amount (A IN)
Automatic phase adjustment (A IN)
Sets phase shift amount (B IN)
Automatic phase adjustment (B IN)
Selects reference frequency source
Sets voltage sensitivity (A IN)
Sets voltage sensitivity (B IN)

R/W
R/W
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
W
R/W
W
R/W
R/W
R/W

✓
✓
－
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓

P5-29
P5-29
P5-30
P5-31
P5-31
P5-31
P5-29
P5-30
P5-29
P5-30
P5-30
P5-30
P5-31
P5-31
P5-32
P5-32
P5-32
P5-32
P5-33

Selects reference signal waveform

5-6

LI5501 / LI5502

5.2 List of commands and command tree

Command
SOURce subsystem:SOUR:FREQ:SOUR:FREQ:MULT:SOUR:VOLT:SOUR:VOLT:OFFS:SOUR:OUTP:SOUR:PHAS::SOUR:PHAS:INIT:SOUR:TYPE
STATus subsystem:STAT:OPER?
:STAT:OPER:COND?
:STAT:OPER:ENAB:STAT:OPER:NTR:STAT:OPER:PTR:STAT:QUES?
:STAT:QUES:COND?
:STAT:QUES:ENAB:STAT:QUES:NTR:STAT:QUES:PTR
SYSTem subsystem:SYST:ERR?
:SYST:FAN:CONT:SYST:REM:LAN:IPAD:SYST:REM:LAN:MASK:SYST:REM:LAN:GATE:SYST:RST
TRIGger subsystem:TRIG:DEL:TRIG:TRIG:SOUR

Function

R/W

*RST

Details

Sets internal oscillator frequency
Sets harmonic order “n” of oscillator output
Sets amplitude of internal oscillator
Sets DC offset of internal oscillator
Sets output state of internal oscillator
Sets phase shift amount of internal oscillator
Initializes phase reference of internal oscillator
Selects internal oscillator waveform

R/W
R/W
R/W
R/W
R/W
R/W
W
R/W

✓
✓
✓
✓
✓
✓
－
✓

P5-33
P5-33
P5-34
P5-34
P5-33
P5-34
P5-34
P5-34

Queries operation status event register
Queries operation status condition register
Operation status event enable register
Negative operation status transition filter
Positive operation status transition filter
Queries questionable event register
Queries questionable condition register
Questionable event enable register
Questionable status negative transition filter
Questionable status positive transition filter

R
R
R/W
R/W
R/W
R
R
R/W
R/W
R/W

－
－
－
－
－
－
－
－
－
－

P5-35
P5-35
P5-35
P5-35
P5-35
P5-36
P5-36
P5-36
P5-36
P5-36

Queries error messages
FAN control
Sets IP address
Sets subnet mask
Sets default gateway
Initialize settings and the configuration memory

R
R/W
R/W
R/W
R/W
W

－
－
－
－
－
－

P5-37
P5-37
P5-37
P5-37
P5-38
P5-38

Sets trigger delay time
Executes trigger (starts recording)
Sets trigger source

R/W
W
R/W

－
－
－

P5-38
P5-38
P5-38

Note: The commands with respect to B IN are only applicable to the LI5502.

5-7

LI5501 / LI5502

5.2 List of commands and command tree

5.2.2 Command tree
The subsystem command tree for the LI5501 / LI5502 is shown below.
Brackets ([ ]) in the tree indicate optional keywords.
<Root>ABORt
CALCulate[1]CALCulate2
CALCulate3
CALCulate4
DATA

Command tree 1/2
OFFSet
MULTiplier
FORMatOFFSetFORMatOFFSet
MULTiplier
OFFSet
COUNt?
DATA?
DELeteFEEDCONTrol
POINtsPERiodFETCh?
INITiate
INPut[1][IMMediate]
OFFSetINPut2

OFFSetINPut3
MEMoryOUTPut[1]
OUTPut2
ROUTe[SENSe]TYPE
STATe[STATe][STATe][TERMinals]
DREServe[1]DREServe2
FREQuency[1]

AUTO
RST
AUTO
RST

ONCE
ONCE

DELeteFREQuency2
FILTer[1]

MULTiplier
SMULtiplier
MULTiplier[LPASs]FILTer2[LPASs]SLOPe
TCONstant
MOV
SLOPe
TCONstant
MOV

PHASe[1]
AUTO

ONCE

AUTO
SOURceAC
AC

ONCE

PHASe2
ROSCillator
VOLTage[1]VOLTage2

5-8

RANGe
RANGe

[UPPer][UPPer]LI5501 / LI5502

5.2 List of commands and command tree

Command tree 2/2
SOURceFREQuency
VOLTate[CW]
MULTiplier[LEVel][IMMediate][AMPLitude]
OFFSET

OUTPutPHASe
INITiate
STATusTYPE
OPERation

QUEStionable

SYSTemTRIGer

ERRor?
FAN
REMote[EVENt]CONDition
ENABleNTRansition
PTRansition[EVENt]CONDition
ENABleNTRansition
PTRansition
CONTrolLAN

IPADdress
MASK
GATE

RST
DELay
[IMMediate]
SOURce5-9LI5501 / LI5502

5.3 Commands

5.3

Commands

5.3.1 Overview
Commands of the LI5501 / LI5502 are classified into common commands compliant with
the IEEE488.2 standard and subsystem commands corresponding to device-specificfunctions.
5.3.1.1 Notation
For convenience, the following notations are used in this manual.
<>Parameters or parameter formats are enclosed in angle brackets (< >).

[]Brackets ([ ]) are used to enclose options, which can be omitted.

{abc|xyz}
A vertical bar (|) indicates that either “abc” or “xyz” can be used.
[abc|xyz]
Square brackets indicate that either “abc” or “xyz” can be used, which canbe omitted.
Uppercase and lowercase letters
Keywords written in uppercase and lowercase letters are long-form
expressions; keywords written in uppercase letters only are short-form
expressions.
5.3.1.2 SCPI commands
The program messages of the LI5501 / LI5502 consist of the common commands andsubsystem commands. Here, these command formats and the subsystem command tree are
explained.
◼ Common commands
The common commands are for control of the general instrument functions.
The command syntax is illustrated in “Figure 5-1”.
*

SP

KeywordParameter?

Figure 5-1 Common command syntax

5-10

LI5501 / LI5502

5.3 Commands

The keyword in “Figure 5-1” are composed of three alphabetic characters. In this figure,SP represents a space (ASCII code 32).
◼ Subsystem commands
The subsystem commands are for executing specific instrument functions. They consistof a root keyword, one or more lower-level keywords, a parameter, and a suffix.
Examples of a command and query are shown below.
:OUTPut:STATe ON:OUTPut:STATe?
“OUTPut” is a root-level keyword that is concatenated with a second-level keyword and“ON” is a parameter.
◼ Subsystem command syntax
The subsystem command syntax is illustrated in “Figure 5-2”.

:

:

,

SP

KeywordParameter

Suffix?

Figure 5-2 Subsystem command syntax[Keywords]
The keyword in “Figure 5-2” is a text strings of up to 12 characters that begins with aletter of the alphabet. The remaining characters are uppercase or lowercase alphabetic
characters, underscore characters, or numerals.
Most of the keywords shown in “5.3.3 Commands description” are composed of a
mixture of uppercase and lowercase characters. Here, uppercase characters indicate
short-form expressions and the mixture of uppercase and lowercase characters
indicates long-form keywords. For convenience and explanation, uppercase andlowercase characters are used in keywords, but actual commands are case insensitive.
The “Table 5-3” shows an example for the keyword “OUTPut”.

5-11

LI5501 / LI5502

5.3 Commands

KeywordOUTPUT
OUTP
OutpUt
oUTP
OUTPU
OU

Table 5-3 Keywords that can be interpreted or not
Description
Can be used as the long form
Can be used as the short form
Keywords are case insensitive.
This can be used as the long form.
Keywords are case insensitive.
This can be used as the short form.
This cannot be used, because it does not correspond to either thelong form or short form.
This cannot be used, because it does not correspond to either thelong form or short form.

[Keyword separators]
The colons that appear in “Figure 5-2” are interpreted as keyword separators. The
keyword separator serves to separate upper-level keyword and lower-level keyword in
the command tree.
The colon that appears at the beginning of the subsystem commands is interpreted asa root specifier. The root specifier sets the current path as the root.
[Keyword omission]
For the commands shown in “5.3.3 Commands description”, a keyword enclosed insquare brackets ([ ]) can be omitted. When the keyword is omitted, the instrument
assumes that it has been received and analyzed.
Taking the “:OUTPut[:STATe]” command for example, either the following commands
can be used.
:OUTPut:STATe:OUTPut

5-12

LI5501 / LI5502

5.3 Commands[Parameters]
The parameter formats are described below.
(1) Numerical parameters (<NRf>, <NR1>, <NR2>, and <NR3>)
The numerical parameter formats include integer (<NR1>), real number (floatingpoint) (<NR2>), and real umber (exponent) (<NR3>). <NRf> is a generic expressionthat includes <NR1>, <NR2>, and <NR3>. The syntax for numerical parameters is
illustrated below.

<NR1>
<NR2>
<NR3>

Figure 5-3 Numerical parameter syntax (<NRf>)

Digit

+

−

Figure 5-4 Numerical parameter syntax (<NR1>)

Digit

.

Digit

+

−

Figure 5-5 Numerical parameter syntax (<NR2>)

5-13

LI5501 / LI5502

5.3 Commands

Exponent

Mantissa

Figure 5-6 Numerical parameter syntax (<NR3>)
Here, the syntax for the mantissa and the exponent of “Figure 5-6” is illustrated
below.

Digit
Digit

.
+
Digit
−

.
Digit

Figure 5-7 Mantissa syntax

Digit

E/e
+

−

Figure 5-8 Exponent syntax

5-14

LI5501 / LI5502

5.3 Commands(2) Discrete parameters (<DISC>)
The syntax for discrete parameters is illustrated below.

Selection 1

Selection 2

Selection 3

Selection N

Figure 5-9 Discrete parameter syntax (<DISC>)(3) Boolean parameters (<BOL>)
The syntax for Boolean parameters is illustrated below.
The Boolean parameter value of “0” is interpreted as “false” (OFF) and all the othervalues are interpreted as “true” (ON).

<NBOL>
ON
OFF

Figure 5-10 Boolean parameter syntax (<BOL>)

5-15

LI5501 / LI5502

5.3 Commands(4) Text string parameters (<STR>)
The syntax for text string parameters is illustrated below.

‘‘‘(character)‘

Characterother than ‘“““(character)“

Characterother than “Figure 5-11 Text string parameters (<STR>)[Parameter separators]
The parameter separator will be used between two parameters when two or moreparameters are used in command.
[Query parameters]
Query parameters are specified after the “?” of a query.
[Suffixes]
In some commands, it is possible to set a value by specifying an SI suffix and unit.
The syntax for suffixes is illustrated below.

SP

SI suffix

Unit

Figure 5-12 Suffix syntax

5-16

LI5501 / LI5502

5.3 Commands◼ Program message syntax
The controller can send a combination of two or more common commands andsubsystem commands to the instrument in a single program message. The
program message syntax is illustrated below.

;
Commoncommand

Subsystem
commandNL

Figure 5-13 Program message syntax
Commands are separated by a semicolon.
◼ Response message syntax
Response messages are used by the instrument to send data in response to aquery.
[Response message syntax]
The syntax for response messages is illustrated below.

;,
Response
data

NL

Figure 5-14 Response message syntax
In response messages, commas and semicolons are used as separators. Whenmultiple values are returned by a single command, a response message will bedelineated by commas. When a single program message contains multiple queries,
a response message will be delineated semicolons.

5-17

LI5501 / LI5502

5.3 Commands[Response message data]
The response message data types are described below.
(1) Numerical response data (<NR1>, <NR2>, and <NR3>)The syntax for numerical response data is illustrated below.

Digit
+

−

Figure 5-15 Integer response data syntax (<NR1>)

Digit

.

Digit

+

−

Figure 5-16 NR2 numerical response data syntax (<NR2>)

Digit

.

Digit

+

−

E

Digit
+

−

Figure 5-17 NR3 numerical response data syntax (<NR3>)

5-18

LI5501 / LI5502

5.3 Commands(2) Discrete response data (<DISC>)
The syntax for discrete response data is illustrated below.

Selection 1

Selection 2

Selection 3

Selection N

Figure 5-18 Discrete response data syntax (<DISC>)(3) Numerical Boolean response data (<NBOL>)
The syntax for numerical Boolean response data is illustrated below.

0

1

Figure 5-19 Numerical Boolean response data syntax (<NBOL>)(4) Text string response data (<STR>)
The syntax for text string response data is illustrated below.

”“”(character)”

Characterother than “Figure 5-20 Text string response data syntax (<STR>)

5-19

LI5501 / LI5502

5.3 Commands(5) Defined-length arbitrary block response data (<DBLK>)
The syntax for defined-length arbitrary block response data is illustrated below.

#

Characterother than 0

Digit

Byte
data

Figure 5-21 Defined-length arbitrary block response data syntax (<DBLK>)

5.3.2 Sequential commands
The commands of the LI5501 / LI5502 are all sequential commands. After execution of acommand is completed, the next command will be executed. There are no overlapping
commands.

5-20

LI5501 / LI5502

5.3 Commands

5.3.3 Commands description
This section describes the commands in detail.
Supplement:“4 digits (1 p (10−12) when <10 n (10−9))” in the resolution of the tables
means that the resolution is usually 4 digits, but 1 p (10−12) when a setting
value is less than 10 n (10−9).

5.3.3.1*CLS

Explanation
Comments

5.3.3.2

Clears the event register and error queue
Targets for the clear operation:• Status byte register• Standard event status register• Operation status event register• Error queue*ESE <value>*ESE?

Explanation
Parameter

Response
formatComments

5.3.3.3

Queries the standard event status register<NR1>
The standard event status register will be cleared when the *ESR? query or the *CLS commandis received.

*IDN?

Explanation
Response
formatComments

5.3.3.5

It is initialized when the power is turned on. Not initialized by the “*RST” command*ESR?

Explanation
Response
formatComments

5.3.3.4

Sets and queries the standard event status enable register<value><NRf>Standard event status enable register
Range:
0 to 255
Resolution:
1
Default:
0<NR1>

Queries the instrument-specific information<corporation>,<model>,<serial>,<ver><corporation> <STR>
Company name (NF Corporation)<model><STR>
Model name (LI5501 / LI5502)<serial><STR>
Serial number
<ver>
<STR>
Firmware version
The response is returned without including double quotation marks.
NF Corporation,LI5501 / LI5502,1234567,Ver1.00

*OPC
*OPC?

Explanation
Response
formatComments*OPC:*OPC?:<NR1>

Sets the OPC bit to “1” when all previous commands have ended
Sets “1” to the output buffer when all previous commands have ended

―

5-21

LI5501 / LI5502

5.3 Commands

5.3.3.6*RCL <value>

Explanation
Parameter

Comments

5.3.3.7*RST

Explanation
Comments

5.3.3.8

Initializes settings
Refer to “Table 4-1 Setting items and initial values” what contents to be initialized.

*SAV <value>

Explanation
Parameter

Comments

5.3.3.9

Executes a read from the configuration memory (internal memory)<value><NRf>
Configuration memory number
Range:
0 to 15
Resolution:
1
The No.0 memory is resume memory and settings are not changed.
Contents of the No.15 memory is the factory default setting.

Executes a save to the configuration memory (internal memory)<value><NRf>
Configuration memory number
Range:
1 to 14
Resolution:
1
Refer to “Table 4-1 Setting items and initial values” what contents to be saved.

*SRE <value>*SRE?

Explanation
Parameter

Response
formatComments

5.3.3.10

Queries the status byte register<NR1>
Refer to “5.4.2 Status byte” about status bytes.

*TST?

Explanation
Response
formatComments

5.3.3.12

It is initialized when the power is turned on. Not initialized by the “*RST” command*STB?

Explanation
Response
formatComments

5.3.3.11

Sets and queries the service request enable register<value><NRf>
Service request enable register
Range:
0 to 255
Resolution:
1
Default:
0<NR1>

Executes the self-diagnostic test and queries its results<NR1>
It is the SCPI command. “0” is always returned.

*WAI

Explanation
Comments

Standby for end of overlapping command execution
There are no overlapping commands for the LI5501 / LI5502.

5-22

LI5501 / LI5502

5.3 Commands

5.3.3.13:ABORtExplanation
Comments

5.3.3.14

Stops recording to the measurement data buffer and makes the triggering system idle―

:CALCulate1:FORMat <value>:CALCulate1:FORMat?

Explanation
Parameter

Response
formatComments

5.3.3.15

Sets and queries the measurement parameter to be output to the DATA1<value><DISC> Measurement parameters
REAL:
XA (= RA cos θA)
MLINear:
RA (= X A 2 + YA 2 )IMAGinary:
PHASe:
REAL2:
MLINear2:

YA (= RA sin θA)θAXB (= RB cos θB)
RB (= XB2 + YB2 )IMAGinary2:
PHASe2:MLINear3:
PHASe3:

YB (= RB sin θB)θBRA / RB (amplitude ratio of A IN to B IN)
θA - θB (phase difference between A IN and B IN)<DISC>
Example) When setting parameter to XA, enter “:CALCulate1:FORMat REAL”.

:CALCulate1:MULTiplier <value>:CALCulate1:MULTiplier?

Explanation
Parameter

Response
formatComments

5.3.3.16

Sets and queries EXPAND multiplier on the A IN side<value><NRf>
Multiplier [times]
Range:
1 to 1000
Resolution:
1<NR1>
The EXPAND multiplier only affects X, Y, and R parameters.
It does not affect the other parameters.
1-2-5 sequence is recommended.

:CALCulate1:OFFSet <value>:CALCulate1:OFFSet?

Explanation
Parameter

Response
formatComments

Sets and queries the offset value for the X output on the A IN side<value><NRf>
Offset [%]Range:-120.00 to +120.00
Resolution:
0.01
<NR2>
―

5-23

LI5501 / LI5502

5.3 Commands

5.3.3.17:CALCulate2:FORMat <value>:CALCulate2:FORMat?

Explanation
Parameter

Response
formatComments

5.3.3.18

Sets and queries the measurement parameter to be output to the DATA2<value><DISC> Measurement parameters
REAL:
XA (= RA cos θA)
MLINear:
RA (= X A 2 + YA 2 )IMAGinary:
PHASe:
REAL2:
MLINear2:

YA (= RA sin θA)θAXB (= RB cos θB)
RB (= XB2 + YB2 )IMAGinary2:
PHASe2:MLINear3:
PHASe3:

YB (= RB sin θB)θBRA / RB (amplitude ratio of A IN to B IN)
θA - θB (phase difference between A IN and B IN)<DISC>―:CALCulate2:OFFSet <value>:CALCulate2:OFFSet?

Explanation
Parameter

Sets and queries the offset value for the Y output on the A IN side<value><NRf>
Offset [%]Range:-120.00 to +120.00
Resolution:
0.01

Response
formatComments<NR2>

5.3.3.19―:CALCulate3:MULTiplier <value>:CALCulate3:MULTiplier?

Explanation
Parameter

Sets and queries EXPAND multiplier on the B IN side<value><NRf>
Multiplier [times]
Range:
1 to 1000
Resolution:
1

Response
formatComments<NR1>

5.3.3.20

The EXPAND multiplier only affects X, Y, and R parameters.
It does not affect the other parameters.
1-2-5 sequence is recommended.

:CALCulate3:OFFSet <value>:CALCulate3:OFFSet?

Explanation
Parameter

Sets and queries the offset value for the X output on the B IN side<value><NRf>
Offset [%]Range:-120.00 to +120.00
Resolution:
0.01

Response
formatComments

<NR2>
―

5-24

LI5501 / LI5502

5.3 Commands

5.3.3.21:CALCulate4:OFFSet <value>:CALCulate4:OFFSet?

Explanation
Parameter

Response
formatComments

5.3.3.22

Queries the number of data sampling points recorded in the measurement data buffer<NR1>―:DATA:DATA? <value>

Explanation
Parameter
Response
formatComments

5.3.3.24―:DATA:COUNt?

Explanation
Response
formatComments

5.3.3.23

Sets and queries the offset value for the Y output on the B IN side<value><NRf>
Offset [%]Range:-120.00 to +120.00
Resolution:
0.01
<NR2>

Queries the contents of the measurement data buffer (measurement values)<value><DISC> Size [points]
Range:
1 to 65536<NR1> | <DISC>:DATA:DELete

Explanation
Comments

Clears the measurement data buffer―

5-25

LI5501 / LI5502

5.3 Commands

5.3.3.25:DATA:FEED <value>:DATA:FEED?

Explanation
Parameter

Sets and queries measurement data parameters recorded in the measurement data buffer<value><NRf>
Measurement data parameters
Weight:1: STATUS
2: FREQ-H (upper bits of reference signal frequency)
4: FREQ-L (lower bits of reference signal frequency)
8: XA (X value on A IN side)
16: YA (Y value on A IN side)
32: RA (R value on A IN side)
64: θA (θ value on A IN side)
128: XB (X value on B IN side)
256: YB (Y value on B IN side)
512: RB (R value on B IN side)
1024: θB (θ value on B IN side)
2048: RATIO (amplitude ratio of A IN to B IN)
4096: PHASE (phase difference between A IN and B IN)

Response
formatComments<NR1>

5.3.3.26

Example) When selecting RA and θA, enter “:DATA:FEED 96”.
Refer to “6.1.1 Setting of measurement data parameters” about STATUS.

:DATA:FEED:CONTrol <value>:DATA:FEED:CONTrol?

Explanation
Parameter

Response
formatComments

5.3.3.27

Sets and queries whether or not to be recorded in the measurement data buffer<value><DISC> Whether recording or not
ALWays: Records measurement data
NEVer:
Does not record measurement data
<DISC>―:DATA:POINts <value>:DATA:POINts?

Explanation
Parameter

Sets and queries the measurement data buffer size
<value><DISC> Size [points]
Range: 1 to 65536 or INFinity

Response
formatComments<NR1> or <DISC>“INFinity” indicates that recording continues until the measurement buffer is full.

5-26

LI5501 / LI5502

5.3 Commands

5.3.3.28:DATA:PERiod <value>:DATA:PERiod?

Explanation
Parameter

Sets and queries recording interval to the measurement data buffer<value><NRf>
Recording interval [s]Range:
0.4 μs to 26.2 ms
Resolution:
0.4 μsSuffix “U” (10−6) and “M” (10−3) and unit “S” are available.

Response
formatComments<NR2>

5.3.3.29:FETCh?

Explanation
Response
formatComments

5.3.3.30

Comments

Automatically adjusts the PSD input offset on the A IN side only once―

The PSD input offset amount on the A IN side is restored to the factory default setting.
―:INPut2:OFFSet:AUTO:ONCE

Explanation
Comments

5.3.3.34

When recording to the measurement data buffer is enabled and the triggering system is idle, thesystem transitions to the awaiting trigger state.
If the measurement data buffer is full during recording, the system becomes the idle state.
It cannot become the awaiting trigger state, while the measurement data if full.
Clear the buffer if necessary.

:INPut[1]:OFFSet:RST

Explanation
Comments

5.3.3.33

Query the measurement data set by the “:DATA:FEED” command.

:INPut[1]:OFFSet:AUTO:ONCE

Explanation
Comments

5.3.3.32

Queries the latest measurement data
<NR1>

:INITiate[:IMMediate]

Explanation

5.3.3.31

It takes 0.4 μs per measured data parameter.

Automatically adjusts the PSD input offset on the B IN side only once―

:INPut2:OFFSet:RST

Explanation
Comments

The PSD input offset amount on the B IN side is restored to the factory default setting.
―

5-27

LI5501 / LI5502

5.3 Commands

5.3.3.35:INPut3:TYPE <value>:INPut3:TYPE?

Explanation
Parameter

Sets and queries the reference signal waveform<value><DISC> Edge
SINusoid: Sine wave (edge: rising slope intersects 0 V)
TPOS:
TTL level rising edge
TNEG:
TTL level falling edge

Response
formatComments<DISC>

5.3.3.36―:MEMory:STATe:DELete <value>

Explanation
Parameter

Clears contents of designated configuration memory<value><NRf>
Memory number
Range: 1 to 14

Response
formatComments<NR1>

5.3.3.37―:OUTPut[1][:STATe] <value>:OUTPut[1][:STATe]?

Explanation
Parameter

Sets and queries the output state of the DATA1 terminal<value><BOL>
Output state
Enables output of the DATA1 terminal
ON｜1:
Disables output of the DATA1 terminal
OFF｜0:

Response
formatComments<NBOL>

5.3.3.38―:OUTPut2[:STATe] <value>:OUTPut2[:STATe]?

Explanation
Parameter

Sets and queries the output state of the DATA2 terminal<value><BOL>
Output state
Enables output of the DATA2 terminal
ON｜1:
Disables output of the DATA2 terminal
OFF｜0:

Response
formatComments<NBOL>

5.3.3.39―:ROUTe[:TERMinals] <value>:ROUTe[:TERMinals]?

Explanation
Parameter

Sets and queries the reference signal source<value><DISC> Reference signal source
RINPut:Input signal to the REF IN terminal
IOSC:
Internal oscillator

Response
formatComments<DISC>―

5-28

LI5501 / LI5502

5.3 Commands

5.3.3.40[:SENSe]:DREServe[1] <value>[:SENSe]:DREServe[1]?

Explanation
Parameter

Response
formatComments

5.3.3.41

Sets and queries the dynamic reserve on the A IN side<value><DISC> Dynamic reserve
HIGH:
High dynamic reserve (when noise level is high)MEDium: Medium dynamic reserve
LOW2:
Low dynamic reserve
LOW1:
Lower dynamic reserve (when noise level is low)
<DISC>―[:SENSe]:DREServe2 <value>[:SENSe]:DREServe2?

Explanation
Parameter

Response
formatComments

5.3.3.42

Sets and queries the dynamic reserve on the B IN side<value><DISC> Dynamic reserve
HIGH:
High dynamic reserve (when noise level is high)MEDium: Medium dynamic reserve
LOW2:
Low dynamic reserve
LOW1:
Lower dynamic reserve (when noise level is low)
<DISC>―[:SENSe]:FILTer[1][:LPASs]:MOV <value>[:SENSe]:Filter[1][:LPASs]:MOV?

Explanation
Parameter

Response
formatComments

5.3.3.43

Sets and queries the averaging time of the moving average filter on the A IN side<value><NRf>
Averaging time [s]<DISC>
Range: OFF, AUTO, or| 1E−6 to 100 (1-2-5 sequence)
Suffix “U” (10-6) and “M” (10-3) and unit “S” are available.
<DISC>
If an arbitrary number is entered, it will be rounded to the nearest value.

[:SENSe]:FILTer[1][:LPASs]:SLOPe <value>[:SENSe]:Filter[1][:LPASs]:SLOPe?

Explanation
Parameter
Response
formatComments

Sets and queries the attenuation slope of the time constant filter on the A IN side<value><NRf>
Attenuation slope [dB/oct]
Range: 6 | 12 | 18 | 24
<NR1>
―

5-29

LI5501 / LI5502

5.3 Commands

5.3.3.44[:SENSe]:FILTer[1][:LPASs]:TCONstant <value>[:SENSe]:Filter[1][:LPASs]:TCONstant?

Explanation
Parameter
Response
formatComments

5.3.3.45

Sets and queries the time constant of the time constant filter on the A IN side<value><NRf>
Time constant [s]Range: 1E−6 to 10E+3 (1-2-5 sequence)<NR3>―[:SENSe]:FILTer2[:LPASs]:MOV <value>[:SENSe]:Filter2[:LPASs]:MOV?

Explanation
Parameter

Response
formatComments

5.3.3.46

Sets and queries the averaging time of the moving average filter on the B IN side<value><NRf>
Averaging time [s]<DISC>
Range: OFF, AUTO, or 1E−6 to 100 (1-2-5 sequence)
Suffix “U” (10-6) and “M” (10-3) and unit “S” are available.
<DISC>
If an arbitrary number is entered, it will be rounded to the nearest value.

[:SENSe]:FILTer2[:LPASs]:SLOPe <value>[:SENSe]:Filter2[:LPASs]:SLOPe?

Explanation
Parameter
Response
formatComments

5.3.3.47

Sets and queries the attenuation slope of the time constant filter on the B IN side<value><NRf>
Attenuation slope [dB/oct]
Range: 6 | 12 | 18 | 24
<NR1>―[:SENSe]:FILTer2[:LPASs]:TCONstant <value>[:SENSe]:Filter2[:LPASs]:TCONstant?

Explanation
Parameter
Response
formatComments

5.3.3.48

Sets and queries the time constant of the time constant filter on the B IN side<value><NRf>
Time constant [s]Range: 1E−6 to 10E+3 (1-2-5 sequence)<NR3>―[:SENSe]:FREQuency[1]?

Explanation
Response
formatComments

Queries the frequency<NR2> value
Range: 9.5E−3 to 1.05E+6, Resolution: 7digits, Unit: Hz―

5-30

LI5501 / LI5502

5.3 Commands

5.3.3.49[:SENSe]:FREQuency[1]:MULTiplier <value>[:SENSe]:FREQuency[1]:MULTiplier?

Explanation
Parameter
Response
formatComments

5.3.3.50

Sets and queries the harmonic order “n” when measuring a harmonic on the A IN side<value><NRf>
Harmonic order “n”
Range: 1 to 63<NR1>―[:SENSe]:FREQuency[1]:SMULtiplier <value>[:SENSe]:FREQuency[1]:SMULtiplier?

Explanation
Parameter
Response
formatComments

5.3.3.51

Sets and queries the subharmonic order “m” common to the A IN and B in side when measuringsubharmonics<value><NR1>
Subharmonic order “m”
Range: 1 to 64<NR1>―[:SENSe]:FREQuency2:MULTiplier <value>[:SENSe]:FREQuency2:MULTiplier?

Explanation
Parameter
Response
formatComments

5.3.3.52

Sets and queries the harmonic order “n” measuring a harmonic on the B IN side<value><NR1>
Harmonic order “n”
Range: 1 to 63<NR1>―[:SENSe]:PHASe[1] <value>[:SENSe]:PHASe[1]?

Explanation
Parameter

Response
formatComments

5.3.3.53

Sets and queries the phase shift amount on the A IN side<value><NRf>
Phase shift amount [°]Range:-180.000 to +179.999
Resolution:
0.001
<NR2>
―

[:SENSe]:PHASe[1]:AUTO:ONCE

Explanation
Comments

Automatically adjusts the phase shift amount so that the A IN side θ becomes zero
When this adjustment is done, signal amplitude can be determined from the parameter “X” andphase change can be determined from the parameter “Y”.

5-31

LI5501 / LI5502

5.3 Commands

5.3.3.54[:SENSe]:PHASe2 <value>[:SENSe]:PHASe2?

Explanation
Parameter

Response
formatComments

5.3.3.55―[:SENSe]:PHASe2:AUTO:ONCE

Explanation
Comments

5.3.3.56

Sets and queries the phase shift amount on the B IN side<value><NRf>
Phase shift amount [°]Range:-180.000 to +179.999
Resolution:
0.001
<NR2>

Automatically adjusts the phase shift amount so that the B IN side θ becomes zero
When this adjustment is done, signal amplitude can be determined from the parameter “X” andphase change can be determined from the parameter “Y”.

[:SENSe]:ROSCillator:SOURce <value>[:SENSe]:ROSCillator:SOURce?

Explanation
Parameter

Response
formatComments

5.3.3.57

Sets and queries the reference frequency source for frequency synthesis<value><DISC> Reference frequency source
INTernal: Internal
EXTernal: External (10 MHz IN terminal)<DISC>―[:SENSe]:VOLTage[1]:AC:RANGe[:UPPer] <value>[:SENSe]:VOLTage[1]:AC:RANGe[:UPPer]?

Explanation
Parameter

Response
formatComments

Sets and queries the voltage sensitivity on the A IN side<value><NRf>
Voltage sensitivity [V]When the dynamic reserve is HIGH
Range: 5E-6 to 1 (1-2-5 sequence)
When the dynamic reserve is MED
Range: 1E-6 to 1 (1-2-5 sequence)
When the dynamic reserve is LOW2
Range: 100E-9 to 100E-3 (1-2-5 sequence)
When the dynamic reserve is LOW1
Range: 10E-9 to 10E-3 (1-2-5 sequence)
Suffix “N” (10-9), “U” (10-6), and “M” (10-3) and unit “V”, “MAX”, and“MIN” are available.
<NR2>
If the voltage sensitivity is out of range due to changing the dynamic reserve, it is automatically
set to the nearest value within the range.

5-32

LI5501 / LI5502

5.3 Commands

5.3.3.58[:SENSe]:VOLTage2:AC:RANGe[:UPPer] <value>[:SENSe]:VOLTage2:AC:RANGe[:UPPer]?

Explanation
Parameter

Response
formatComments

5.3.3.59

Sets and queries the voltage sensitivity on the B IN side<value><NRf>
Voltage sensitivity [V]When the dynamic reserve is HIGH
Range: 5E-6 to 1 (1-2-5 sequence)
When the dynamic reserve is MED
Range: 1E-6 to 1 (1-2-5 sequence)
When the dynamic reserve is LOW2
Range: 100E-9 to 100E-3 (1-2-5 sequence)
When the dynamic reserve is LOW1
Range: 10E-9 to 10E-3 (1-2-5 sequence)
Suffix “N” (10-9), “U” (10-6), and “M” (10-3) and unit “V”, “MAX”, and“MIN” are available.
<NR2>
If the voltage sensitivity is out of range due to changing the dynamic reserve, it is automatically
set to the nearest value within the range.

:SOURce:FREQuency[:CW] <value>:SOURce:FREQuency[:CW]?

Explanation
Parameter

Response
formatComments

5.3.3.60

Sets and queries the internal oscillator frequency<value><NRf>Frequency [Hz]Range:
9.5E-3 to 1.05E+6
Resolution:
6 digits
Suffix “M” (10-3), “K” (103), and “MA” (106) and unit “HZ”, “MAX”, and“MIN” are available.
<NR2>―:SOURce:FREQuency:MULTiplier <value>:SOURce:FREQuency:MULTiplier?

Explanation
Parameter
Response
formatComments

5.3.3.61

Sets the oscillator output frequency to “n” times the internal oscillator frequency and queries the
harmonic order “n”<value><NRf>
Harmonic order “n”
Range: 1 to 63<NR1>―:SOURce:OUTPut <value>:SOURce:OUTPut?

Explanation
Parameter
Response
formatComments

Sets and queries the output state of the OSC OUT terminal<value><BOL>
Output state
ON | OFF<NBOL>
Only AC waveforms can be turned on and off.
The DC offset is not affected.

5-33

LI5501 / LI5502

5.3 Commands

5.3.3.62:SOURce:PHASe <value>:SOURce:PHASe?

Explanation
Parameter

Response
formatComments

5.3.3.63―:SOURce:PHASe:INITiate <value>

Explanation
Comments

5.3.3.64

Sets and queries the phase of the internal oscillator<value><NRf>
Phase [°]
Range:−180.000 to +179.999
Resolution:
0.001
<NR2>

Executes phase synchronization of the internal oscillator―:SOURce:TYPE <value>:SOURce:TYPE?

Explanation
Parameter

Response
formatComments

5.3.3.65

Sets and queries the wave form of the internal oscillator<value><DISC>
Waveform
SINusoid:
Sine wave
TTL:
TTL-level square wave
<DISC>―:SOURce:VOLTage[:LEVel][:IMMediate][:AMPLitude] <value>:SOURce:VOLTage[:LEVel][:IMMediate][:AMPLitude]?

Explanation
Parameter

Response
formatComments

5.3.3.66

Sets and queries the output amplitude of the internal oscillator<value><NRf>
Amplitude [Vrms]
Range:
0.000 to 1.000
Resolution:
0.001
<NR2>
―

:SOURce:VOLTage[:LEVel][:IMMediate]:OFFSet <value>:SOURce:VOLTage[:LEVel][:IMMediate]:OFFSet?

Explanation
Parameter

Response
formatComments

Sets and queries the DC offset voltage of the internal oscillator<value><NRf>
Offset voltage [VDC]
Range:-5.000 to +5.000
Resolution:
0.005
<NR2>
―

5-34

LI5501 / LI5502

5.3 Commands

5.3.3.67:STATus:OPERation:CONDition?

Explanation
Response
formatComments

5.3.3.68

Queries the operation status condition register<NR1>―:STATus:OPERation:ENABle <value>:STATus:OPERation:ENABle?

Explanation
Parameter

Response
formatComments

5.3.3.69

It is initialized when the power is turned on. Not initialized by the “*RST” command:STATus:OPERation[:EVENt]?

Explanation
Response
formatComments

5.3.3.70

Sets and queries the operation status event enable register<value><NRf>
Operation status event enable register
Range:
0 to 65535
Resolution:
1
Default:
0<NR1>

Queries the operation status event register<NR1>
It will be cleared if the event register is queried or the “*CLS” command is received.

:STATus:OPERation:NTRansition <value>:STATus:OPERation:NTRansition?

Explanation
Parameter

Response
formatComments

5.3.3.71

Sets and queries the negative operation status transition filter<value><NRf>
Negative operation status transition filter
Range:
0 to 65535
Resolution:
1
Default:
0<NR1>
It is initialized when the power is turned on. Not initialized by the “*RST” command:STATus:OPERation:PTRansition <value>:STATus:OPERation:PTRansition?

Explanation
Parameter

Response
formatComments

Sets and queries the positive operation status transition filter<value><NRf>
Positive operation status transition filter
Range:
0 to 65535
Resolution:
1
Default:
5296 (LI5501)
5552 (LI5502)<NR1>
It is initialized when the power is turned on. Not initialized by the “*RST” command

5-35

LI5501 / LI5502

5.3 Commands

5.3.3.72:STATus:QUEStionable:CONDition?

Explanation
Response
formatComments

5.3.3.73

Queries the questionable condition register<NR1>―:STATus:QUEStionable:ENABle <value>:STATus:QUEStionable:ENABle?

Explanation
Parameter

Response
formatComments

5.3.3.74

It is initialized when the power is turned on. Not initialized by the “*RST” command:STATus:QUEStionable[:EVENt]?

Explanation
Response
formatComments

5.3.3.75

Sets and queries the questionable event enable register<value><NRf>Questionable event enable register
Range:
0 to 65535
Resolution:
1
Initial value:0<NR1>

Queries the questionable event register<NR1>
It is cleared when querying the event register or the “*CLS” command is received.

:STATus:QUEStionable:NTRansition <value>:STATus:QUEStionable:NTRansition?

Explanation
Parameter

Response
formatComments

5.3.3.76

Sets and queries the questionable status negative transition filter<value><NRf>
Negative transition filter
Range:
0 to 65535
Resolution:
1
Initial value:0<NR1>
It is initialized when the power is turned on. Not initialized by the “*RST” command:STATus:QUEStionable:PTRansition <value>:STATus:QUEStionable:PTRansition?

Explanation
Parameter

Response
formatComments

Sets and queries the questionable status positive transition filter<value><NRf>
Positive transition filter
Range:
0 to 65535
Resolution:
1
Initial value:
339 (LI5501)
351 (LI5502)<NR1>
It is initialized when the power is turned on. Not initialized by the “*RST” command

5-36

LI5501 / LI5502

5.3 Commands

5.3.3.77:SYSTem:FAN:CONTrol <value>:SYSTem:FAN:CONTrol?

Explanation
Parameter

Response
formatComments

5.3.3.78―:SYSTem:ERRor?

Explanation
Response
formatComments

5.3.3.79

Sets and queries the internal fan setting<value><DISC> Fan control
ON:
Always on
OFF:
Always off
AUTO:
When the CPU temp. exceeds about 60 °C, it is turned on
and when the CPU temp. falls below about 55 °C, it isturned off.
<DISC>

Queries remote errors<code>,<message><code><NR1>
Error code
<message><STR>
Error message• <message> includes double quotation marks.
• The error queue can hold up to 16 error messages and the message can be read one by one inorder of oldest first.
• If there are more than 16 error messages, the last message in the error queue will be replaced
by “Queue overflow” and a new error will not be added until there is a room in the error queue.
• The error queue will be cleared when the “*CLS” command is received.

:SYSTem:REMote:LAN:IPADdress <value>:SYSTem:REMote:LAN:IPADdress?

Explanation
Parameter

Response
formatComments

5.3.3.80

Sets and queries the IP address<value><STR> IP address
Range: 0 to 255
XXX. XXX. XXX. XXX
Example) 192. 168. 0. 2
<STR>―

:SYSTem:REMote:LAN:MASK <value>:SYSTem:REMote:LAN:MASK?

Explanation
Parameter

Sets and queries the subnet mask
<value><STR> Subnet mask
Range: 0 to 255
XXX. XXX. XXX. XXX
Example) 255. 255. 255. 0

Response
formatComments

<STR>
―

5-37

LI5501 / LI5502

5.3 Commands

5.3.3.81:SYSTem:REMote:LAN:GATE <value>:SYSTem:REMote:LAN:GATE?

Explanation
Parameter

Sets and queries the default gateway<value><STR> Default gateway
Range: 0 to 255
XXX. XXX. XXX. XXX
Example) 192. 168. 0. 1

Response
formatComments<STR>

5.3.3.82:SYSTem:RST

Explanation
Comments

5.3.3.83―

Initializes settings
Unlike the “*RST” command, this command also clears contents of the configuration memories
from No.1 to 14.
―:TRIGger:DELay <value>:TRIGer:DELay?

Explanation
Parameter
Response
formatComments

5.3.3.84―:TRIGger[:IMMediate]

Explanation
Comments

5.3.3.85

Sets and queries the trigger delay time<value><NRf>
Delay time [s]Range: 0 to 1.67 s (1.6777212 s)<NR2>When the measurement data buffer is enabled, measurement data is recorded in the buffer by atrigger.
―:TRIGger:SOURce <value>:TRIGer:SOURce?

Explanation
Parameter

Response
formatComments

Sets and queries the trigger source<value><DISC> Trigger source
EXTernal:
By external signal
BUS:
By communication
Use the “:TRIGger[:IMMediate]” command.
<DISC>―

5-38

LI5501 / LI5502

5.4 Status system

5.4

Status system

5.4.1 Overview of status system
The status system of the LI5501 / LI5502 is illustrated in “Figure 5-22”.
Operation status registers

Questionable status registers

Operation condition register

Questionable condition register

Positive/negativetransition filter

Standard event registers

Positive/negativetransition filter

Operation event register

Standard event
status register

Questionable event register

Operation event
enable register

Standard event status
enable register

Questionable event
enable register

Logical OR

Logical OR

Logical OR

Output queue

Always 0

ROS
OPE MSS ESB MAV QUE

Service request generation

2

1

0

STB
(Status byte register)&&: Logical AND

Logical OR

&
&
&
&
&
&

7

6

5

4

3

2

1

0

SRE
(Service request
enable register)Figure 5-22 Status system

5-39

LI5501 / LI5502

5.4 Status system

5.4.2 Status byte
The definition of the status byte register is described in “Table 5-4”. The status byte can beread by serial polling. In this case, bit “6” is RQS (Request service).
Table5-4 Definitions of the status byte register
Bit

Weight

OPE

7

128

RQS/
MSS

6

64

ESB

5

32

MAV

4

16

QUE
−
−
−

3
2
1
0

8
4
2
1

Condition for setting to “1”When any of the effective bits of
the operation status event
register is set to “1”When SRQ is sent
When one of the effective bits ofthe standard event status
register becomes “1”When a response to the query
has been prepared and can be
output−−−−Condition for setting to “0”When all of the effective bits of theoperation status event register are set
to “0”· When the device clear is received· When RQS reads the status byte byserial polling
When all of the effective bits of thestandard event status register become“0”
When all of responses have been
output and there are no more
responses to be output
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)◼ Relevant commands and queries*STB?
This command can query contents of the status byte register.
Bit “6” is MSS (Master Summary Status).
*SRE, *SRE?
These commands can set and query the service request enable register.
Immediately after the power is turned on, the register will have been cleared to zero.
The status byte register bits will become effective when the corresponding bits in theservice request enable register are set to “1”. The service request will be issued when
any one of the effective bits is set to “1”.
Parameters for setting and response messages to each register are the sums of all theweights of the bits that have the value of “1”.
◼ Checking status when making a query
Normally, a correct response message can be received after a query has been sent, and it
is not necessary to check the MAV bit of the status byte. If it is necessary to proceed withprocesses while the MAV bit is being checked, first check that the MAV bit of the statusbyte is “1” by serial polling after the query is sent and then read the response message.
Then confirm that the MAV bit has changed to “0” and proceed with the next operation.

5-40

LI5501 / LI5502

5.4 Status system

5.4.3 Standard event status
The structure of the standard event status is illustrated in “Figure 5-23”, and the detailsof the status are described in “Table 5-5”. If the bits of the standard event status enableregister are set to “1”, the corresponding bits of the standard event status register will beenabled, and if any of the enabled bits become the value “1”, the ESB bit of the status byte
register will be set to “1”.

Power onPON

7

Always 0 (not used)

URQ

6

Command error

CME

5

Execution error

EXE

4Instrument-specific error

DDE

3

Query error

QYE

2

Always 0 (not used)

RQC

1

Operation completed

OPC

0

&

7

&

6

&

5

&

4

&

3

&

2

&

1

&

0

ESE
(Standard event status
enable register)

ESR(Standard event
status register)Standard event
Status summary

Logical OR

Status byte ESB (bit 5)

Figure 5-23 Structure of the standard event status

5-41

LI5501 / LI5502

5.4 Status system

Table5-5 Contents of the standard event status register
Bit

Weight

PON

7

128

URQ

6

64

CME

5

32

EXE

4

16

DDE

3

8

QYE

2

4

RQC

1

2

OPC

0

1

Content
Power-onThis bit will be set to “1” when the power is turned on. It will remain “0”until the power is turned on again when this register is read and thevalue is cleared to “0”.
User’s request
Always “0” (not used)
Command error
This bit will be set to “1” if there is a syntax error in a remote command.
Execution error
This bit will be set to “1” if a parameter is out of range or there is a
conflict in setting.
Instrument-specific error
This bit will be set to “1” if the error queue is overflowed.
Query error
This bit will be set to “1” if a read attempt is made when there is no datain the output buffer or if the data in the output buffer has been lost.
Request control
Always “0” (not used)
Operation completedThis bit will be set to “1” when processing for all commands up to the*OPC command has been completed.

◼ Relevant commands and queries*ESR?
This command can query contents of the standard event status register.
The register will be cleared to “0” if it is queried. The “*CLS” command also can clear
the register.
The register will have been cleared to “0” immediately after the power is turned on,
but the PON bit will have been set to “1”.
*ESE, *ESE?
These commands can set and query the standard event status enable register.
Set the value “0” to clear the register to “0”.
There are no other clear commands.
The register will have been cleared to “0” immediately after the power is turned on.
Parameters for setting and response messages to each register are the sums of all theweights of the bits that have the value of “1”.

5-42LI5501 / LI5502

5.4 Status system

5.4.4 Operation status
The structure of the operation status is illustrated in “Figure 5-24”.
The operation condition register (OPCR) indicates a status of the LI5501 / LI5502 as shownin “Table 5-6”. The transition filter can detect changes in the conditions and generates
events. Generating an event requires settings of the transition filter. The operation status
event register can store generated events. If the operation status event enable register bits
are set to “1”, the corresponding bits of the operation status event register will be enabled.
If the value of any of the enabled bits is set to “1”, the OPE bit of the status byte will be set
to “1”.
OPCR (Operation status condition register)
OPTR (Positive transition filter)
ONTR (Negative transition filter)

Always 0 (not used)

15

15

15

15

Always 0 (not used)

14

14

14

14

Always 0 (not used)

13

13

13

13

13

Out of sync ULOC

12

12

12

12

12

Always 0 (not used)

11

11

11

11

11

Buffer is full BUF

10

10

10

10

10

Always 0 (not used)

9

9

9

9

9

PSD adjusting BPSD

8

8

8

8

PSD adjusting APSD

7

7

7

7

7

Always 0 (not used)

6

6

6

6

6

Awaiting trigger WTRG

5

5

5

5

5

Recording MEAS

4

4

4

4

4

Always 0 (not used)

3

3

3

3

3

Always 0 (not used)

2

2

2

2

Always 0 (not used)
Always 0 (not used)

1
0

1
0

1
0

&

15

&

14

8

・・・

2

&

1

1

&

0

OPER
(Operation status
event register)・・・

Logical OR

0

OPEE(Operation status event
enable register)

Operation status
summary
Status byte OPE (bit 7)

Figure 5-24 Structure of the operation status

5-43

LI5501 / LI5502

5.4 Status system

Table5-6 Contents of the operation status condition register
Bit
－
－
－
ULOC
－
BUF
－
BPSD
APSD
－
WTRG
MEAS
－
－
－
－

15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0

Weight
32768
16384
8192
4096
2048
1024
512
256
128
64
32
16
8
4
2
1

Content
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Not synchronized with external reference frequency (10 MHz)
Always “0” (not used)
The buffer is full.
Always “0” (not used)
Adjusting DC offset to zero on the B in side
Adjusting DC offset to zero on the A in side
Always “0” (not used)
Awaiting trigger
Recording
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)

Note: When an external trigger is used, the MEAS bit is always “0”.
◼ Relevant commands and queries:STATus:OPERation:CONDition?
This command can query contents of the operation status condition register.
The register will not be cleared to “0” if it is queried
The status of the instrument is always indicated.
:STATus:OPERation[:EVENt]?
This command can query the operation status event register.
The register will be cleared to “0” if it is queried.
The register can also be cleared by the “*CLS” command.
The register will have been cleared to “0” immediately after the power is turned on.

5-44

LI5501 / LI5502

5.4 Status system:STATus:OPERation:ENABle , STATus:OPERation:ENABle?
This command can set and query the operation status event enable register.
Set the value “0” to clear the register to “0”.
There are no other clear commands.
The register will have been cleared to “0” immediately after the power is turned on.
:STATus:OPERation:NTRansition, STATus:OPERation:NTRansition?
:STATus:OPERation:PTRansition, STATus:OPERation:PTRansition?
These commands can set and query the operation status transition filters.
The relationships between a transition filter setting and event register transition are
shown in “Table 5-7”.
Table5-7 Transition filter settings and the event register transitions
Condition register
Positive transition filter bit Negative transition filter bit transition for changing theevent register to “1”“1”“0”“0” → “1”“0”
“1”“1” → “0”“1”
“1”“0” → “1” or “1” → “0”Event register cannot be“0”“0”changed to “1”.
Parameters for setting and response messages to each register are the sums of all theweights of the bits that have the value of “1”.

5-45

LI5501 / LI5502

5.4 Status system

5.4.5 Questionable status
The structure of the questionable status is illustrated in “Figure 5-25”.
The questionable condition register indicates an abnormal staus of the LI5501 / LI5502 asshown in “Table 5-7”. The transition filter can detect changes in the conditions andgenerates events. Generating an event requires settings of the transition filter. The
questionable event register can store generated events. If the event enable register bits are
set to “1”, the corresponding bits of the event register will be enabled. If the value of any ofthe enabled bits is set to “1”, the QUE bit of the status byte will be set to “1”.
QUCR (Questionable condition register)
QPTR (Positive transition filter)

Always 0 (not used)

15

15

15

15

15

Always 0 (not used)

14

14

14

14

14

Always 0 (not used)

13

13

13

13

13

Always 0 (not used)

12

12

12

12

12

Always 0 (not used)

11

11

11

11

11

Always 0 (not used) 10

10

10

10

10

Always 0 (not used)

9

9

9

9

9

Over heat HEAT

8

8

8

8

8

Always 0 (not used)

7

7

7

7

7

Out of sync PHAS

6

6

6

6

6

Always 0 (not used)

5

5

5

5

5

RATIO over ABRO

4

4

4

4

4

B AC over BAO

3

3

3

3

3

B DC over BDO

2

2

2

2

2

A AC over AAO

1

1

1

1

1

A DC over ADO

0

0

0

0

0

Logical OR

QNTR (Negative transition filter)

OPER(Questionable event register)

Questionable status summary

OPEE(Questionable event enable register)Status byte QUE (bit 3)

Figure 5-25 Structure of the questionable status

5-46

LI5501 / LI5502

5.4 Status system

Table5-8 Contents of the questionable condition register
Bit
－
－
－
－
－
－
－
HEAT
－
PHAS
－
ABRO
BAO
BDO
AAO
ADO

15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0

Weight
32768
16384
8192
4096
2048
1024
512
256
128
64
32
16
8
4
2
1

Content

Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Always “0” (not used)
Overheated state

Always “0” (not used)
Not synchronized with external reference signal

Always “0” (not used)
Saturation in ratio operation
Saturation in the previous PSD stage on the B IN side
Saturation after PSD stage on the B in side*
Saturation in the previous PSD stage on the A IN side
Saturation after PSD stage on the A in side**Saturation in the time constant filter, DC GAIN, moving average filter, EXPAND, or
operational parts◼ Relevant commands and queries:STATus:QUEStionable:CONDition?
This command can query contents of the questionable condition register.
The register will not be cleared to “0” if it is queried.
The status of the instrument is always indicated.
:STATus:QUEStionable[:EVENt]?
This command can query the questionable event register.
The register will be cleared to “0” if it is queried.
The register can also be cleared by the “*CLS” command.
The register will have been cleared to “0” immediately after the power is turned on.
:STATus:QUEStionable:ENABle, STATus:QUEStionable:ENABle?
This command can set and query the questionable event enable register.
Set the value “0” to clear the register to “0”.
There are no other clear commands.
The register will have been cleared to “0” immediately after the power is turned on.

5-47

LI5501 / LI5502

5.4 Status system:STATus:QUEStionable:NTRansition, STATus:QUEStionable:NTRansition?
:STATus:QUEStionable:PTRansition, STATus:QUEStionable:PTRansition?
This command can set and query the questionable transition filter.
The relationships between a transition filter setting and event register transition are
shown in “Table 5-9”.
Table5-9 Transition filter settings and the event register transitions
Condition register
Positive transition filter bit Negative transition filter bit transition for changing theevent register to “1”“1”“0”“0” → “1”“0”
“1”“1” → “0”“1”
“1”“0” → “1” or “1” → “0”Event register cannot be“0”“0”changed to “1”.
Parameters for setting and response messages to each register are the sums of all theweights of the bits that have the value of “1”.

5-48

LI5501 / LI5502

5.5 Error messages

5.5

Error messages

In this section, primary errors that occur in the remote control are described.
Table5-10 Error messages 1/2
Error
number0

No error-100

Command error-101

Invalid character-102

Syntax error

-103
-104

Invalid separator
Data type error
Parameter notallowedMissing parameter
Command header
error
Undefined header
Unexpected numberof parameters

-108
-109
-110
-113
-115

Error message-120

Numeric data error

-123
-124

Exponent too large
Too many digits-130

Suffix error-134

Suffix too long-140

Character data error-144

Character data too
long

-150

String data error-200

Execution error-221

Settings conflict-222

Data out of range
Illegal parameter
value

-224

Description
No abnormality
There is an abnormality in the command (no detailed
classification).
There is an abnormality in the text data.
The command or data that cannot be recognized has
been received.
There is an abnormality in the command separators.
The parameter format is inappropriate.
There are too many parameters or there are parameters
where it cannot be used.
Not enough parameters
There is an abnormality in the command header (nodetailed classification).
The command header is undefined.
There is an abnormality in the number of parameters.
There is an abnormality in the numerical data (no detailed
classification).
The exponent is too large (greater than 32000).
A number has too many digits (more than 255-digit).
There is an abnormality in the SI prefix or unit (nodetailed classification).
The SI prefix or unit is too long (more than 7 characters).
There is an abnormality in the text data (no detailed
classification).
The text data is too long.
There is an abnormality in the string data (no detailed
classification).
The command could not be executed (no detailed
classification).
The command cannot be executed because of constraint
conflicts among multiple settings.
The data is outside of the valid range.
The parameters are incorrect (inappropriate other than
“Data type error”).

5-49

LI5501 / LI5502

5.5 Error messages

Table5-10 Error message 2/2
Error
numberError message-310

System error-350

Queue overflow-363

Input buffer overrun
Query
DEADLOCKED
Query
UNTERMINATED
after indefinite
response

-430

-440

Description
An instrument-specific internal error has occurred.
(memory contents were lost, etc.)
The error queue has overflowed and cannot
accommodate new errors.
(more than 16 error queues)
The input buffer has been overflowed.
The buffer was full and the processing cannot proceed.
The output buffer will be cleared.
There was a query following “*IDN?” in the text string(“*IDN?” must be the last query in received text string.).

Errors relevant to the remote control are stored in the error queue and can be read one ata time in order of oldest first with the “:SYSTem:ERRor?” query. If a read operation is
executed after all of the errors have been read, “0, “No error”” will be returned. The error
queue can be cleared with the “*CLS” command.
If a problem occurs that results in data remaining in the input buffer or output buffer, thebuffers can be cleared with the device clear messages (DCL, SDC).
A error other than those described above may occur in some situations. In such case, checkthe error message for a summary.

5-50

LI5501 / LI5502

6． Advanced settings

6.1 Measurement data buffer .....................................6-2
6.1.1 Setting of measurement data parameters .................. 6-2
6.1.2 Format ......................................................................... 6-3
6.1.3 Triggering system ....................................................... 6-5
6.1.4 Sample programs of data acquisition ......................... 6-6

6.2 Configuration memory ..........................................6-8
6.2.1 Recall settings............................................................. 6-8
6.2.2 Save settings .............................................................. 6-8

6.3 FAN control ..........................................................6-9

6-1

LI5501 / LI5502

6.1 Measurement data buffer

6.1

Measurement data buffer

The LI5501 / LI5502 can acquire measurement data in two ways: Streaming, which uses
the internal memory and can acquire a large amount of data, and Querying, which queries
the latest measurement data with the “:FETCh?” command.
This section describes setting items for these data acquisition ways.

6.1.1 Setting of measurement data parameters
Up to 7 measurement data (7 words) parameters to be obtained can be selected from the“Table 6-1”.
Table6-1 Measurement data parameters
WeightParameter

Description

1

STATUS

2

FREQ-H

4

FREQ-L

8
16
32
64
128
256
512
1024
2048
4096

XA
YB
RA
θA
XB
YB
RB
θB
RATIO
PHASE

StatusUpper bits of reference signal
frequency
Lower bits of reference signal
frequency
X value on the A IN side
Y value on the A IN side
R value on the A IN sideθ value on the A IN side
X value on the B IN side
Y value on the B IN side
R value on the B IN sideθ value on the B IN side
Amplitude ratio of RA to RB
Phase difference between θA and θB

Bit length
Streaming
Querying
16 bits
16 bits
16 bits

16 bits

16 bits

20 bits

16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits
16 bits

18 bits
18 bits
20 bits
20 bits
18 bits
18 bits
20 bits
20 bits
20 bits
20 bits

The “STATUS” descriptions are shown in below.
Weight
1
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16384
32768

STATUS―――――――――RATIO over
MOV over (B)MOV over (A)LPF over (B)LPF over (A)ADC over (B)ADC over (A)
―――
―――
―――
―――
OSC over
UNLOCK

Description
Indefinite
Indefinite
Indefinite
Saturation in ratio operation
Saturation in the MOV filter or EXPAND on the B IN side
Saturation in the MOV filter or EXPAND on the A IN side
Saturation in the TC filter or DC GAIN on the B IN side
Saturation in the TC filter or DC GAIN on the A IN side
Saturation in the previous PSD stage on the B IN side
Saturation in the previous PSD stage on the A IN side
Indefinite
Indefinite
Indefinite
Indefinite
Overvoltage at the oscillator output
No synchronization

6-2

LI5501 / LI5502

6.1 Measurement data buffer

6.1.2 Format
1) Streaming
Measured data is read in order of ascending weight of parameters.
The data is sent in blocks of one measurement data without a comma or message
terminator.
The measured value can be obtained using the following formula after converting signed
4-digit hexadecimal (16 bits) to signed 16-bit integer format (−32,768 to 32,767).
Measured value = Measured data × 2−15

× 1.2 × full-scale of a meter (See below.)

The actual value of parameter received in integer format can be determined by the bit
length recorded in the measurement data buffer using the following formula.
Parameter
R
X
Y
RATIO
θ
PHASE

Formula−15

Measured value = Measured data × 2
×1.2 × (Sensitivity / EXPAND)
Measured value = Meter value × (Sensitivity / EXPAND)−15
Meter value = Measured data × 2
×1.2−15
Measured value = Measured data × 2
× (5 / 3) × 2.4 × Sensitivity ratio
Sensitivity ratio =(A IN Sensitivity / B IN Sensitivity) × (A IN EXPAND / B IN EXPAND)
Measured value = Measured data × 2

×180°

−33

16

Frequency−15

Frequency = (A × 2 + B) × 2
× 2.5 MHz
Measured frequency data is transferred after divided unsigned 8-digit
hexadecimal data (32 bits) into A: FREQ-H and B: FREQ-L.
This is converted to an unsigned 16-bit integer format (0 to 65,535) and themeasurement value can be calculated from it.

If the sensitivity setting when querying measured data is different from the setting
when recording the data, correct measurement results cannot be obtained.

6-3

LI5501 / LI5502

6.1 Measurement data buffer2) Querying
Measured data can be read by the “:FETCh?” command in order of ascending weight ofparameters.
Each value is separated by commas.
The actual value of parameter received in integer format can be determined by the bit
length recorded in the measurement data buffer using the following formula.
Parameter
R
X
Y
RATIO
θ
PHASE
Frequency

Formula−19

Measured value = Measured data × 2
× 1.2 × (Sensitivity / EXPAND)
Measured value = Meter value × (Sensitivity / EXPAND)−17
Meter value = Measured data × 2
× 1.2
If a calculated meter value is greater than or equal to 1.2, subtract 2.4 toobtain a range of −1.2 to 1.2.
−19
Measured value = Measured data × 2
× 2.4 ×Sensitivity ratio
Sensitivity ratio =(A IN Sensitivity / B IN Sensitivity) × (A IN EXPAND / B IN EXPAND)−19
Measured value = Measured data × 2
× 180°
If a calculated value is greater than or equal to 180, subtract 360 to obtain arange of −180.000 to +179.999.
−37
20
Frequency = (A × 2 + B) × 2
× 2.5 MHzA measured frequency data is transferred after divided into A: FREQ-H and
B: FREQ-L.

If the sensitivity setting when querying measured data is different from the setting
when recording the data, correct measurement results cannot be obtained.

6-4

LI5501 / LI5502

6.1 Measurement data buffer

6.1.3 Triggering system
This section describes settings for continuous data acquisition using the measurement
data buffer.
1) Sampling intervalThis is the sampling interval for data acquisition.
⚫ Range: 0.4 μs to 26.2 ms
2) Buffer size
This is the number of samples per trigger.
⚫ Range: 1 to 65536 or INF (continuous)
3) Trigger source
Select the trigger source from the remote control command by computer (BUS) or
external signal (EXT) to the trigger pin in the power supply terminal.
When the trigger source is EXT, the instruments is triggered by falling edge of an
external signal.
⚫ Trigger source: BUS or EXT4) Trigger delay
When the trigger source is EXT, set the trigger delay.
When the trigger source is BUS, adjust a timing on a computer side.
⚫ Range: 0 to 1.67 s

Power-onInitialization*RST:ABORtAborts recording

Idle state:INITitate
Enables recording

TRIG-SOURCE setting
TRIG EXT

TRIG BUS

Trigger settings
RecordingAwaiting trigger:TRIG
Trigger delay(EXT only)
Recording
Sampling interval
Recording points
per trigger
For continuous data acquisition,
set the buffer size to INF.

A computer receives data
・If the buffer is not full, data is output continuously.
・If the buffer is full, the instrument will be the awaiting state fordata transmission.

6-5

LI5501 / LI5502

6.1 Measurement data buffer

6.1.4 Sample programs of data acquisition
Sample programs using the measurement data buffer are shown below.
Example 1) Records measurement data at arbitrary timing and then reads them together
Send (":ABOR")' If recording is in progress, it is aborted.
Send (":DATA:FEED 96")
' Sets the measurement data set for recording
Send (":DATA:POIN 1")' Sets the number of samples per trigger
Send (":DATA:FEED:CONT ALW")' Enables recording into the measurement data buffer
Send (":TRIG:SOUR BUS")' Sets the trigger source to the remote control command
Send (":INIT")' Transition to the awaiting trigger state
Send (":TRIG")' Applies the trigger to repeatedly record measurement data
' If the measurement data buffer becomes full during recording,the trigger system enters the idle state and further triggers are not accepted.
Send (":DATA:DATA? X")' X: Number of required data points' Requests sending measurement data
Receive (MLIN_1, PHAS_1, MLIN_2, PHAS_2, MLIN_3, PHAS_3, ...)
' Reads out measurement data from the measurement data buffer

6-6

LI5501 / LI5502

6.1 Measurement data buffer

Example 2) Reads out measurement data while recording it
Send (":ABOR")' If recording is in progress, it is aborted.
Send (":DATA:FEED 96")
' Sets the measurement data set for recording
Send (":DATA:POIN INF")' Sets the number of samples per trigger
Send (":DATA:FEED:CONT ALW")' Enables recording into the measurement data buffer
Send (":DATA:PER 1E-3")' Sets the recording cycle of measurement data
Send (":TRIG:SOUR BUS")' Sets the trigger source to the remote control command
Send (":INIT")' Transition to the awaiting trigger state
Send (":TRIG")' Applies the trigger to repeatedly record measurement data
' If the measurement data buffer becomes full during recording,the trigger system enters the idle state and further triggers are not accepted.
Send (":DATA:COUNt?")' Queries the number of data sampling points recorded in the buffer' The number of samples requested by computer is less than or equal torecorded number of samples.
Send (":DATA:DATA? X")' X: Number of required data points' Requests sending measurement data
Receive (MLIN_1, PHAS_1, MLIN_2, PHAS_2, MLIN_3, PHAS_3, ... )' Receives data on requested number of samples' If readout is faster than recording, the buffer doesn’t become fulland recording can continue.
' If the buffer becomes full, no more data will be recorded.
Send (":DATA:FEED:CONT NEV")' Stops recording after acquiring necessary data

6-7

LI5501 / LI5502

6.2 Configuration memory

6.2

Configuration memory

There are 16 sets of the configuration memory from No.0 to 15.
The No.1 to 14 memories are for user’s memory. Frequently used settings can be saved tothe memories and recalled when needed.
The No.15 memory is factory default settings memory. The factory default settings can berecalled.
The No.0 memory is the RESUME memory. The current settings arealways saved to the memory during power-on and saved even when the
power is turned off.
The MODE switch on the rear panel is used to recall settings stored in
the configuration memory.

MODE Switch“0” to “9” and “A” to “F” on the MODE switch correspond to the configuration memory
numbers “0” to “9” and “10” to “15” respectively.
The table below summarizes the configuration memory.
Memorynumber0
1 to 14
15

Function
RESUME
User’smemoryFactory default
settings

User operation
Recall*RST
Initialized―――
By command
Unchangedor switch
By command―――or switch

Save
Always
By command―――:SYS:RST
Initialized
Initialized―――

The RESUME memory can be initialized by the “*RST” command.
The RESUME and user’s memory can be initialized by the “:SYS:RST” command.

6.2.1 Recall settings1) MODE switch
The number set on the MODE switch is recalled at startup.
If the MODE switch is changed during power-on, settings stored in the memory number
will be recalled.
If the mode switch is set to “0” when the power is turned on, the settings at the time thepower is previously turned off are recalled.
2) Recall settings by remote control
Settings stored in specified memory number can be recalled by remote control.

6.2.2 Save settings
1) Save current settings
Current settings (contents of the RESUME memory) can be saved to a specified user’s
memory.

6-8

LI5501 / LI5502

6.3 FAN control

6.3

FAN control

This instrument contains electronic components that generate a lot of heat in small
enclosure. Ambient temperature above 40 °C will shorten the life of the instrument.
Therefore, the cooling fan is equipped with the instrument.
In acoustic or vibration measurement, the cooling fan may affect the measurement system,so turn it off if necessary.
The fan control can be set to always ON, always OFF, or AUTO. For details, refer to“5.3.3.77 :SYSTem:FAN:CONTrol <value>”.
In “AUTO” setting, the fan is automatically controlled according to measured temperatureof the CPU inside the instrument. The fan will be turned on when the measured
temperature exceeds about 60 °C and turned off when the temperature drops below about
55 °C.
The ventilation holes are provided on the sides of the instrument, and the airflow direction
is as shown in the figure below.
The life of the fan in continuous operation is about 30,000 hours.
When the fan is turned on, dust or foreign matter may be absorbed into the enclosure,
resulting in corrosion and failure. Periodic maintenance (cleaning) is recommended.

IntakeExhaust！ CAUTION

As an internal temperature of the instrument becomes hot, the enclosure and metalparts of the connectors also become hot.

6-9

LI5501 / LI5502

6.3 FAN control(Blank)6-10

LI5501 / LI5502

7． Troubleshooting

7.1 Error messages ....................................................7-2
7.2 Abnormalities during measurement ......................7-3

7-1

LI5501 / LI5502

7.1 Error messages

7.1

Error messages

To check operational status of the instrument, check the LEDs on the rear panel or use theremote command. Refer to “5.4 Status system” and “5.5 Error messages” about thestatus system and error messages due to communication.
Main errors that occur during normal measurement are described in this section, alongwith their causes and how to deal with them.
If the instrument requires repair, please contact the NF Corporation or its authorized
agent.
When requesting repair, please provide the error message and symptom.
An error message that are not described in this manual may also appear during unusual
operations such as updating the instrument firmware. If other manuals are provided, referto them as well.

7-2

LI5501 / LI5502

7.2 Abnormalities during measurement

7.2

Abnormalities during measurement

In addition to error detection by remote control, LEDs on the rear panel can be used todetect abnormalities.
LED nameand Color
CONDITION
Green

EXT-CLKGreenUNLOCK
OrangeCOMM ERR
OrangeA AC OVLD
OrangeA DC OVLD
OrangeDescription and cause

Handling

・The LED does not light up.
・The LED blinks during startup.
The calibration data was lost andthe specified performance cannot
be maintained.
・The LED blinks.
When the external 10 MHz
setting is enabled, no external 10
MHz signal is applied.

・Review the power supply voltage.
・Contact the NF Corporation or its
authorized agent and request a
repair.

・The LED lights up.
The instrument is notsynchronized with a reference
signal・The LED lights up.
Communication failure occurred.
The data buffer is full.
・The LED lights up.
Saturation in the previous PSD
stage on the A IN side

・The LED lights up.
Saturation after the PSD on the
A IN side
・The LED lights up.

B AC OVLD*
OrangeSaturation in the previous PSD
stage on the B IN side

B DC OVLD*
Orange・The LED lights up.
Saturation after the PSD on the
B IN side・Input a specified 10 MHz signal to
the 10MHz IN terminal.
・Check if the input 10 MHz input
signal can be driven.
・The instrument can work with theinternal reference clock evenwhen the LED is blinking.
・An external reference signal is notconnected.
・The related settings are notappropriate.
・The amplitude of the input signal
is too low or out of the frequency
range.
・Change data buffer settings.

・Check input signal amplitude on
the A IN side.
・Review the dynamic reserve
setting on the A IN side.
・Review settings of the time
constant filter, DC GAIN, OFFSET,
and EXPAND on the A IN side.
・Check input signal amplitude on
the B IN side.
・Review the dynamic reserve
setting on the B IN side.
・Review settings of the time
constant filter, DC GAIN, OFFSET,
and EXPAND on the B IN side.

*B AC/DC OVLD are LI5502 only.

7-3

LI5501 / LI5502

7.2 Abnormalities during measurement(Blank)7-4

LI5501 / LI5502

8． Maintenance

8.1 Introduction ..........................................................8-2
8.2 Daily maintenance ................................................8-3
8.3 Storage, repacking, and transport ........................8-3
8.4 Checking the version number...............................8-3
8.5 Performance tests ................................................8-4
8.5.1 Introduction ................................................................. 8-4
8.5.2 Voltage measurement accuracy ................................. 8-6
8.5.3 Analog outputs voltage accuracy................................ 8-8
8.5.4 Phase accuracy .......................................................... 8-9
8.5.5 Amplitude accuracy of the internal oscillator ............ 8-11

8.6 Calibration .......................................................... 8-12

8-1

LI5501 / LI5502

8.1 Introduction

8.1

Introduction

The maintenance items required to keep the instrument in good condition for use are listed
below.
 Operational inspection

Check whether the instrument is functioning properly.

 Performance test

Check whether the instrument is operating at the rated
performance levels.

 Adjustment and calibration

If the instrument does not meet the specifications, the
NF Corporation will adjust and calibrate the instrument
to restore performance.

 RepairIf adjustment and calibration fail to improve
performance, the NF Corporation will investigate thecause, locate the failure, and repair the instrument.

This instruction manual describes how you can easily check for proper operation of the
instrument and performance test methods.
For more advanced inspection, adjustment, calibration, and repair, contact the NF
Corporation or its authorized agent.
！ WARNING

There are high temperature locations and Precision electronic components inside theinstrument. Do not remove the cover.
Inspection of the interior of the instrument should not be performed by anyone otherthan service technicians that have been trained to avoid hazards.

8-2

LI5501 / LI5502

8.2 Daily maintenance

8.2

Daily maintenance

Before use, install the instrument in a location that satisfies the installation conditions.
Installation conditions → Refer to “2.2.2 Installation environment”
Clean the outside of the instrument using a soft cloth as necessary. To remove stubborn
soiling, use a cloth that has been dampened with a mild detergent solution and squeezed
well to remove excess liquid. Do not use organic solvents such as paint thinner or benzene,
or a chemically-treated cloth. Doing so may result in degradation, a cloudy appearance, or
peeling of paint.

8.3

Storage, repacking, and transport

The LI5501 / LI5502 should be stored in a location that satisfies the storage conditions.
Storage conditions → Refer to “2.2.2 Installation environment”.
When packing the instrument for transportation, etc., use a box that is sufficiently strong
and large enough to provide a surplus of space. Fill the box with packing materials thatcan withstand the weight of the instrument so that it is fully protected.
Make sure that the package is handled with care to avoid strong shock during transport.

8.4

Checking the version number

Because the instrument continues to be improved, instruments may have the same model
name but may have different firmware versions. Instruments that have different firmware
versions may differ in operation. When a problem arises, be sure to include the firmware
version number with description of the problem.
Use the “*IDN?” command to check the firmware version number.
◼ Serial number
If the serial number cannot be checked by the “*IDN?” command, check the nomenclaturelabel on the bottom of the instrument.

Label ofpassing inspection

Nomenclature label

8-3

LI5501 / LI5502

8.5 Performance tests

8.5

Performance tests

8.5.1 Introduction
The performance tests are a part of preventive maintenance and is performed to prevent
degradation of instrument performance. The tests should be done for acceptanceinspection, periodic inspections, and whenever it is necessary to check the performance,such as after repair.
The simple performance tests described here can be performed using commerciallyavailable standards and measurement instruments. For advanced tests, please contact the
NF Corporation or its authorized agent. This is available for a charge.
If the performance tests indicate that the instrument does not satisfy the specifications,calibration or repair is required. In that case, please contact the NF Corporation or its
authorized agent.
1)

Test environment
The performance tests should be performed under the following conditions.

2)

・Ambient temperature

23 ± 5 °C

・Ambient humidity

20 to 70 %RH, no condensation

・Power supply requirements± 15 VDC, 1 A or more・Warm-up time

20 minutes or more

Preparation for tests
Before doing the tests, initialize the settings.
To initialize the settings, set the MODE switch to “F” and power-on.

8-4

LI5501 / LI5502

8.5 Performance tests

3)

Test equipment
The measurement instruments needed for the tests are listed as below.
Product
Function generator

Digital multimeter

Oscilloscope
OthersCoaxial cables
Shorted plug
Adapter

Required specifications
Waveform: Sine wave
Frequency: 1 mHz to 1.05 MHz
Amplitude: 10 mVrms to 7 Vrms
TTL output synchronized with sine wave
AC voltmeter (true rms)
(100 mV to 1 V range)
Accuracy: ± 0.1 % (10 Hz to 20 kHz)DC voltmeter(100 mV to 100 V range)
Accuracy: ± 0.04 %Bandwidth: 10 MHz or moreTime / division: 10 s / division or fasterFor monitoring

Example model
WF1947(NF Corp.)
34401A(Keysight)

TBS2072B(Tektronix)

50 Ω, BNC, equivalent to RG58/U
BNC shorted plug or 50 Ω BNC terminator
BNC, Tee adapter

8-5

LI5501 / LI5502

8.5 Performance tests

8.5.2 Voltage measurement accuracy
In the following descriptions, the LI5502 is shown in the connection diagrams as arepresentative.
LI5502 settings:

Measurement
Instrument
settings:
Connections:

Measurement
method:Judgement(passing range):

Set the reference signal source to INT OSC (internal oscillator).
Set the frequency to 1 kHz.
Set the time constant to 100 ms.
Set the attenuation slope to 24 dB/oct.
Set the measurement parameter to R.
Turn on the oscillator output.
The amplitude, dynamic reserve, and sensitivity are shown in
the following table.
Perform the test for each input.
Set the multimeter to AC voltage measurement mode.
Connect a coaxial cable from one side of a tee adapter at the
OSC OUT terminal to the A IN terminal. Connect anothercoaxial cable from the other side of the adapter to themultimeter.
Set the following specified amplitude, dynamic reserve, andsensitivity and read the measured value and multimeter.
See the table below.

Coaxial cable (1m)

Tee adapter

Multimeter
0.9921 V AC

Coaxial cable (1m)
BNC female to dual
banana plug adapter

8-6

LI5501 / LI5502

8.5 Performance tests

judgement
Input

Dynamic
reserve

Sensitivity[rms]Internal
oscillator
amplitude [rms]

HIGH

1V

1V

MED

1V

1V

R: Measured value [rms]S: DMM reading [rms] R / S

A IN
LOW2

100 mV

100 mV

LOW1

10 mV

10 mV

HIGH

1V

1V

MED

1V

1V

B IN
LOW2

100 mV

100 mV

LOW1

10 mV

10 mV

_.___

0.995 to1.005 *_.___

0.995 to
1.005

_.___

0.995 to1.005 *_.___

0.995 to1.005 *_.___

0.995 to1.005 *_.___

0.995 to
1.005

_.___

0.995 to1.005 *_.___

0.995 to1.005 *_.____V_.____V_.____V_.____V_ _ _ . _ mV
_ _ _ . _ mV
_ _ . _ _ mV
_ _ . _ _ mV_.____V_.____V_.____V_.____V_ _ _ . _ mV
_ _ _ . _ mV
_ _ . _ _ mV
_ _ . _ _ mV

Passingrange(R / S)*These are supplementary values, not guaranteed values.
These values are generally in this range, but if these are significantly out of range, theinstrument may be malfunctioning.

8-7

LI5501 / LI5502

8.5 Performance tests

8.5.3 Analog outputs voltage accuracy
LI5502 settings:

Measurement
Instrument
settings:
Connections:
Measurement
method:Judgement(passing range):

Set the reference signal source to INT OSC (internal oscillator).
Set the frequency to 1 kHz.
Set the internal oscillator amplitude to 0 V.
Set the time constant to 100 ms.
Set the attenuation slope to 24 dB/oct.
Set the measurement parameter of DATA1 to X and that of
DATA2 to Y.
Set the offset values for both X and Y as shown in the tablebelow.
Set the multimeter to DC voltage measurement mode.
Connect a shorted plug or 50Ω terminator to the A IN terminal.
Connect the DATA1 or DATA2 terminal to the digital
multimeter with a coaxial cable.
Set the following specified offset value and read themeasurement value on the multimeter.
See the table below.

Shortedplug
Multimeter
9.9999 V DC
Coaxial cable
BNC female to dual
banana plug adapter

Judgement
Offset values(X and Y)
+100%
0%
−100%

DMM reading
Passing range (± 10 V ± 60 mV at ± 100% and ± 10 mV at 0%)
DATA1
DATA2
(X)
(Y)
+__.___V+__.___V_ _ _ . _ _mV_ _ _ . _ _ mV-__.___V-__.___V

8-8

LI5501 / LI5502

8.5 Performance tests

8.5.4 Phase accuracy
1) Relative to external reference signal
LI5502 settings:

Measurement
Instrument
settings:
Connections:

Measurement
method:Judgement(passing range):

Set the reference signal source to REF IN (external reference).
Set the reference signal waveform to SIN.
Set the sensitivity to 1 V and dynamic reserve to MED.
Set the measurement parameter to θ.
Set the time constant to 100 ms.
Set the attenuation slope to 24 dB/oct.
Set the wave form to a sine wave.
Set the frequency to 1 kHz and the amplitude to 1 Vrms.
Connect a coaxial cable from one side of a tee adapter at thefunction generator output terminal to the A IN terminal.
Connect another coaxial cable from the other side of the adapter
to the REF IN terminal.
Read the measured θ value by remote control.
See the table below.

Function generator
1.00000 kHz
1.000 Vrms
FUNC OUT SYNC OUT

Coaxial cable (1m)

Tee adapter

Coaxial cable (1m)

Use same length and characteristics cables.
Shorter cables are preferable.

Judgement
Input
A IN
B IN

Frequency
1 kHz
1 kHz

θ
___.__°___.__°

Passing range *−1 to +1 °−1 to +1 °*This is a supplementary value, not guaranteed value.

8-9LI5501 / LI5502

8.5 Performance tests

2) Relative to the internal oscillator
LI5502 settings:
Set the reference signal source to INT OSC (internal oscillator).
Set the wave form to a sine wave.
Set the frequency to 1 kHz.
Set the internal oscillator amplitude to 1 Vrms.
Turn on the oscillator output.
Set the measurement parameter to θ.
Set the time constant to 100 ms.
Set the attenuation slope to 24 dB/oct.
Measurement
Only a coaxial cable is used.
Instrument
settings:
Connections:
Connect the A IN terminal and OSC OUT terminal with a coaxial
cable.
Measurement
Read the measured θ values by remote control.
method:Judgement
See the table below.
(passing range):

Coaxial cable (1m)Judgement (same as 1) Relative to external reference signal)
Input
A IN
B IN

Frequency
1 kHz
1 kHz

θ
___.__°___.__°

Passing range *−1 to +1 °−1 to +1 °*This is a supplementary value, not guaranteed value.

8-10

LI5501 / LI5502

8.5 Performance tests

8.5.5 Amplitude accuracy of the internal oscillator
LI5502 settings:

Set the reference signal source to INT OSC (internal oscillator).
Set the wave form to a sine wave.
Set the frequency to 1 kHz.
Set the internal oscillator amplitude to 1 Vrms.
Turn on the oscillator output.

Measurement
Instrument
settings:
Connections:Set the multimeter to AC voltage measurement mode.
Connect the OSC OUT terminal to the multimeter with acoaxial cable.
Read the measurement value on the multimeter.

Measurement
method:Judgement(passing range):

See the table below.

Coaxial cable (1m)

Multimeter
0.9999 V AC

BNC female to dual
banana plug adapter

Judgement
Frequency
1 kHz

Oscillator
amplitude
1 Vrms

DMM reading [rms]Passing range_ .___ _V

0.955 to 1.045 V

8-11

LI5501 / LI5502

8.6 Calibration

8.6

Calibration

If the performance tests reveal that the instrument fails to satisfy the specifications, the
NF Corporation will adjust or calibrate the instrument to restore performance.
If calibration is required, please contact the NF Corporation or its authorized agent.
Adjustment or calibration that is performed outside the warranty period is available for acharge.

8-12LI5501 / LI5502

9． Specifications

9.1 Input section .........................................................9-2
9.1.1 Signal inputs ............................................................... 9-2
9.1.2 Reference signal input ................................................ 9-2
9.1.3 External reference frequency input............................. 9-3

9.2 Output section ......................................................9-4
9.2.1 Oscillator output .......................................................... 9-4
9.2.2 Analog data outputs .................................................... 9-4

9.3 Analysis function ..................................................9-5
9.4 Digital data output .............................................. 9-10
9.5 Remote control interface .................................... 9-10
9.6 Miscellaneous specifications .............................. 9-11
9.7 External dimensions ........................................... 9-13

Nominal, typical, supplementary and approximate values
These values imply the supplemental data of this instrument and do notguarantee the instrument performance.

9-1

LI5501 / LI5502

9.1 Input section

9.1

Input section

This section describes specifications of the input terminals such as the signal input
terminals and reference signal input terminal.

9.1.1 Signal inputs
Input connector

BNC

No. of channels

LI5501: 1 (Terminal name: A IN)
LI5502: 2 (Terminal names: A IN, B IN)

Input type

Single-ended

Input impedance

1 MΩ (nominal value), 20 pF in parallel (supplementary value)

Frequency range

DC to 1.05 MHz

Voltage gain

0.2x / 1x / 10x / 100x (AC GAIN)

Voltage gain temperature drift± 250 ppm / °C (supplementary value)
1 kHz frequency
Input-referred noise

25 nV/√Hz (supplementary value)
1 kHz frequency, 100x voltage gain, input shorted

Harmonic distortion−70 dBc or less (supplementary value)
1 Vrms input siganl, 1x voltage gain, 20 Hz to 100 kHz,second and third harmonics respectively

Maximum input voltage (for linear operation)±5V
Non-destructive maximum input voltage± 10 V
Impedance between the signal ground and chassis ground22 Ω (nominal value), ± 1 V

9.1.2 Reference signal input
Input connector

BNC

No. of channels

1 (Terminal name: REF IN)

Imput impedance

1 MΩ (nominal value), 20 pF in parallel (supplementary value)

Frequency range

DC to 1.05 MHz

Input voltage range

Sine wave (SIN): 0.4 to 6 Vp-p
Square wave (TTL): 0 to 5 Vhigh level 2.6 V or more, low level 0.8 V or lessPulse width (square wave) 100 ns or more (both high and low levels)
Non-destructive maximum input voltage± 10 V

9-2

LI5501 / LI5502

9.1 Input section

9.1.3 External reference frequency input
Input connector

BNC

No. of channels

1 (Terminal name: 10MHz IN)

Frequency range

10 MHz ± 0.2 %Waveform

Sine wave or square wave (45 to 55 % duty cycle)

Signal level

0.5 to 5 Vp-p

Non-destructive maximum input voltage
10 Vp-pInput impedance

500 Ω (approximate value)

Input couplingAC± 42 Vpeak max (DC + AC)(allowable voltage to enclosure)Withstand voltage

Reference frequency source Internal or external
If a reference signal for frequency synthesis is applied to the
10MHz IN terminal from an external source, the internal
oscillator generates the reference signal synchronized withthat external 10 MHz frequency. Therefore, measurement canbe performed without applying an external reference signal.

9-3

LI5501 / LI5502

9.2 Output section

9.2

Output section

This section describes specifications of the output terminals such as the internal oscillator
output terminal and measurement data output terminals.

9.2.1 Oscillator output
Output connector

BNC

No. of channels

1 (Terminal name: OSC OUT)

Output frequency

Synchronization frequency or internal oscillator frequency

Waveform

Sine wave or square wave

Amplitude

Sine wave: 1 Vrms, 1 mVrms resolution
Square wave: TTL level

Amplitude accuracy± (4 %＋5 mV)sine wave, 1 kHz frequency

DC offset voltage± 5 V (available only with sine wave,
5 mV resolution, nominal value)

Recommended load

± 15 mA or more
500 Ω or more (resistor connected to signal ground)

Output impedance

53 Ω (nominal value)

Harmonic distortion-70 dBc or less (supplementary value)

Maximum output current

20 Hz to 100 kHz, no load, sine wave, 1 Vrms amplitudesecond and third harmonics respectively, 0 V DC offset

9.2.2 Analog data outputs
Output connector

BNC

No. of channels

2 (Terminal names: DATA1, DATA2)

Maximum update rate

312.5 k Samples/sFrequency range

10 kHz or more

Output voltage range
Output impedance± 12 V (no load), 16-bit resolution± 10 mA or more440 Ω (nominal value)

Output voltage accuracy± (0.5 % + 10 mV), relative to measured value

Maximum output current

9-4

LI5501 / LI5502

9.3 Analysis function

9.3

Analysis function

The instrument works as a dual-phase lock-in amplifier.
The LI5502 can also measure amplitude ratio and phase difference between two channels.
a) Measurement signal system
Frequency range

9.5 mHz to 1.05 MHz

No. of channels

LI5501: 1 (A IN)
LI5502: 2 (A IN, B IN)b) Phase sensitive detector section
Phase sensitive detector Dual-phase (R cosθ, R sinθ)Orthgonality
Dynamic reserve± 0.001 ° (supplementary value)
100 dB or more (supplementary value)⚫ Dynamic reserve
The dynamic reserve is a value that expresses a margin against noise.
It indicates how much noise is tolerated relative to the full scale of the voltage
sensitivity.
DR = Allowable maximum noise level / Voltage sensitivity (full scale of signal)
The actual DR value depends on voltage sensitivity, frequency difference between asignal and noise, and settings of the time constant filter.
To realize 100 dB or more, 100 ms or more time constant and 24 dB/oct attenuation
slope or equivalent filter settings are required.

Time constant filter
Time constant (TC)

1 μs to 10 ks (1-2-5 sequence)⚫ 1-2-5 sequence is a sequence of numbers repeating as “1, 2, 5, 10, 20, 50, …”.

Attenuation slope (SLOPE)
6 / 12 / 18 / 24 dB/oct⚫ Time constant filter
It is cascade-connected first-order lowpass filters and eliminates noise and ripples
associated with phase detection.
The filter is realized with a digital filter that demonstrates the same response as
an analog filter.
The time constant corresponds to the response time of the first-order lowpass filter
and the attenuation slope corresponds to the number of cascade-connected stages(6 dB/oct per stage) of the filter.
The greater these settings, the greater the effect of noise rejection and ripple
rejection.

9-5

LI5501 / LI5502

9.3 Analysis function

Voltage sensitivity
DR setting

See the table below (1-2-5 sequence).
LOW1 / LOW2 / MED / HIGH
(linked with AC GAIN)
DR
LOW1
LOW2
MED
HIGH

AC GAIN
100x
10x
1x
0.2x

Voltage sensitivity
10 nVrms to
10 mVrms
100 nVrms to 100 mVrms
1 μVrms to
1 Vrms
5 μVrms to
1 Vrms⚫ Voltage sensitivity
The DR setting corresponds to the gain of the analog circuit (AC GAIN) and
restricts the range of the voltage sensitivity.
Within this range, the voltage sensitivity (DC GAIN) can be set, which amplifies adigital signal after the PSD.

Voltage measurement accuracy± 0.5 % (1 kHz and 1 Vrms input siganl, DR MED,
1 Vrms voltage sensitivity)
Moving average filter
Averaging time

OFF (0.4 μs), 1 μs to 100 s (1-2-5 sequence),
AUTO (Inverse of reference signal frequency is set
as averaging time.)⚫ Moving average filter (MOV)This filter removes noise by moving average of averaging time.
A notch filter can be set with integer multiples of the averaging time as the period.
When the averaging time is equal to inverse of reference signal frequency, ripples
associated with PSD is greatly reduced and the output is almost settled in the
averaging time, so it is easy to obtain a fast response by setting a small time
constant.
However, if signal frequency is high, the ripple suppression effect may not be
sufficient.
When the filter is OFF, the minimum averaging time of 0.4 μs is set.

EXPAND

1x to 1000x⚫ EXPANDThe EXPAND function amplifies a signal after the moving average filter.
If this function is used without the moving average filter, lower bits will be missing.
Therefore, it is recommended to use the filter with an appropriate amount of
averaging time when using this function.
1-2-5 sequence is recommended.

9-6

LI5501 / LI5502

9.3 Analysis function

Phase noise

0.001 °rms (1 kHz, 18 dB/oct or more attenuation slope)
Supplementary value; reference signal is external
1 Vrms sine wave, 100 ms time constant, MOV OFF
When a reference signal is noisy or has high jitter or theamplitude is less than 1 Vrms, this specification may not besatisfied.

Phase temperature drift ± 0.02 ° / °C
Supplementary value when input and reference signal areboth 1 kHz and 1 Vrms sine waves.
Phase measurement accuracy±1°
Supplementary value when input and reference signal areboth 1 kHz and 1 Vrms sine waves.
Phase shift amount−180.000 ° to +179.999 °, 0.001 ° resolution

PSD offset adjustment

Capable of removing a DC component of ± 25% of full-scale⚫ About PSD offset adjustment
When the PSD offset adjustment is executed, the average value of the DC
component for about 420 ms is measured, and then the correction value is set.
By the adjustment execution command, the adjustment is ececuted.
By the adjustment reset command, the correction value returns to the factory
default setting.

9-7

LI5501 / LI5502

9.3 Analysis functionc) Reference signal system
Signal source

REF IN (external reference) / INT OSC (internal oscillator)⚫ REF IN
When the internal oscillator cannot be synchronized with external reference signal,
the instrument will be UNLOCK state.
When the internal oscillator can be synchronized with external reference signal,
the instrument will be LOCK state within the specified synchronization time.
⚫ INT OSC
Immediately synchronized with the internal oscillator

Waveform

SINE / TTL POS / TTL NEG⚫ SINE (SIN)
Frequency-stable waveform that crosses the 0 V only twice per period
When using a square wave, use it with 10 to 90 % duty factor.
Point where a signal crosses 0 V from below to above is 0°⚫ TTL POS (TPOS)
Frequency-stable waveform that crosses the threshold level only twice per period
The rising edge is 0°.
⚫ TTL NEG (TNEG)
Frequency-stable waveform that crosses the threshold level only twice per period
The falling edge is 0°.

Frequency range

9.5 mHz to 1.05 MHz

Synchronization time

2 periods + 50 ms or less (supplementary value)

Frequency resolution

0.3 mHz

Frequency measurement accuracy± 40 ppm (1 Hz or more, waveform: TTL POS / TTL NEG)
Harmonic measurement
A reference frequency given to the detector can be set ton/m times of reference signal frequency.
Range of n (harmonic): 1 to 63
Range of m (sub-harmonic): 1 to 64
Note:

n/m times of reference signal frequency needs tobe within the synchronization frequency range.

d) Internal oscillator
Frequency range

9.5 mHz to 1.05 MHz

Frequency resolution

0.1 mHz

Frequency accuracy± 30 ppm (supplementary value)

9-8LI5501 / LI5502

9.3 Analysis functione) Output section of measurement values
Parameters
LI5501: XA , YA , RA , θA
LI5502: XA , YA , RA , θA , XB , YB , RB , θB , RATIO, PHASE⚫ Parameters
X: In-phase component (= R cosθ)
Y: Quadrature component (= R sinθ)
R: Signal amplitude, RMS value(= √(X2+Y2))
θ: Signal phase (= tan−1 (Y / X))
The subscripts indicate the measured channel (A:CH-A, B:CH-B).
RATIO: Amplitude ratio between the two channels (RA / RB,)
PHASE: Phase defference between the two channels (θA－θB)⚫ Example of measuring amplitude ratio
Whenmeasured RA is 60 mVrms at sensitivity is 0.1 Vrms (60% full-scale) andmeasured RB is 100 mVrms at sensitivity is 0.2 Vrms (50% ful-scale),the measured amplitude ratio (G) is equalt to 1.2 (= 60 %FS / 50 %FS).
The actual amplitude ratio can be calculated using the above measured value andthe ratio of the sensitivity settings.
Taking the above as an example, since the sensitivity ratio is 0.5 (= 0.1/ 0.2), theactual amplitude ratio is 0.6 (= 1.2 (G) × 0.5).

Measurement range

X, Y± 0 to 120 % relative to voltage sensitivity
Resolution: 18 bits

R

0 to 120 % relative to voltage sensitivity
Resolution: 19 bits

RATIO

0 to 200 %Resolution: 19 bits

θ, PHSAE−180.000 ° to +179.999 °Resolution: 0.001 °Voltage range of analog outputs
X, Y± 10 VDC(when ± 100 % relative to voltage sensitivity)

R

10 VDC(when 100 % relative to voltage sensitivity)

RATIO

10 VDC (when 200 % amplitude ratio)

θ, PHASE± 10 VDC(when 179.999 ° or −180.000 ° respectively)

Offset± 120.00 % relative to voltage sensitivity for X and Y,
0.01% resolution

9-9

LI5501 / LI5502

9.4 Digital data output

9.4

Digital data output

Output mode

Querying / Streaming⚫ Querying
Responds to the command query with ASCII⚫ Streaming
Outputs binary data continuously
There are seven 16-bit registers and measured data can be output at a specified
sample period.
The maximum transfer rate is 300k word/s.

Sampling interval

0.4 μs × (1 to 65536)

Output parameters

LI5501:

XA , Y A , R A , θ A

LI5502:

XA , YA , RA , θA , XB , YB , RB , θB , RATIO , PHASE

LI5501/2:

Reference signal frequency, Status⚫ Reference signal frequency
When the output mode is Streaming, measured frequency data is divided into
upper frequency data (16 bits) and lower frequency data (16 bits).
⚫ Status
Not synchronized with reference signal (UNLOCK)
Saturation in the previous PSD stage (ADC over)Saturation in the time constant filter (LPF over)Saturation in the moving average filter (MOV over)Saturation in the ratio operation (RATIO over)
Overvoltage at the oscillator output (OSC over)

9.5

Remote control interfaceUSB

USB 2.0 full speed, device class CDC

LAN

10BASE-T / 100BASE-TX, TCP/IP (socket communication)

9-10

LI5501 / LI5502

9.6 Miscellaneous specifications

9.6

Miscellaneous specifications

Power supply
Recommended power supply Voltage± 15 VDC ± 2%
linear power supply (with dual tracking) recommended
Operating voltage range ± 14 to 16 VDC
Current consumption

approximately +400 mA / -110 mA (LI5501)
approximately +480 mA / -120 mA (LI5502)
factory default settings, no input signals, no loads

Connector

D-SUB 9pin (equivalent to DELC-J9PAF-20L9 (JAE))

Configuration memory

16 sets (switchable by MODE switch on the rear panel)
One of them is for resume function and another has factory
default settings.

Resume function

Last operating settings will be restored when the
instrument is restarted.

Environmental conditions
Operation

0 to +50 °C, 5 to 85 %RH(absolute humidity 1 to 25 g/m3, no condensation)
Altitude of 2000 m or less

Performance guarantee

23 ± 5 °C, 5 to 85 %RH(absolute humidity 1 to 25 g/m3, no condensation)
Altitude of 2000 m or less

Storage−10 to +60 °C, 5 to 95 %RH(absolute humidity 1 to 29 g/m3, no condensation)
%RH
90
80
Storage70

Operation

60
50
40

Performance
guarantee

30
20
10
0

−10

0

10

20

9-11

30

40

50

60 C

LI5501 / LI5502

9.6 Miscellaneous specifications

Pollution degree

2 (indoor use)

Warm-up time

20 minutes

RoHS directive

Directive 2011/65/EU

EMC

EN 61326-1, EN 61326-2-1
Applies to instruments that have a CE marking on the bottom

External dimensions

200 mm (W) × 30 mm (H) × 150 mm (D)excluding metal fittings and protruding parts

WeightApproximately 700 g
main unit only, excluding accessories and metal fittings

9-12

LI5501 / LI5502

9-13
Top

Top

Left side

Left side

Front panel: Printed circuit
Rear panel: Printed circuit
Cover:
Light-gray coating (Munsell 6.0PB 7.6 / 1.2)
Bottom:Aluminum conversion coatings

Surface treatment

Right side

Right side

External dimensions

Figure 9-1 External dimensions of the LI5501

LI5501 / LI5502
Front

Front

Rear

9.7

Rear

9.7 External dimensions

9-14

Left side

Left sideTop

Top

Figure 9-2 External dimensions of the LI5502

LI5501 / LI5502
Front

Front

Rear

Rear

Front panel: Printed circuit
Rear panel: Printed circuit
Cover:
Light-gray coating (Munsell 6.0PB 7.6 / 1.2)
Bottom:Aluminum conversion coatings

Surface treatment

Front panel: Printed circuit
Rear panel: Printed circuit
Cover:
Light-gray coating (Munsell 6.0PB 7.6 / 1.2)
Bottom:Aluminum conversion coatings

Surface treatment

Right side

Right side

9.7 External dimensions

ーーーー WARRANTY ーーーー
NF Corporation certifies that this instrument was thoroughly tested and inspected and found tomeet its published specifications when it was shipped from our factory. In the unlikely event thatyou experience an issue during use, please contact our company or agency of our company fromwhich you purchased the instrument.
All NF products are warranted against defects in materials and workmanship for a period of one
year from the date of shipment. During the warranty period, NF will repair the defective instrument
without any charge for the parts and labor.
For repair service under warranty, the instrument must be returned to either NF or an agent
designated by NF. The Purchaser shall prepay all shipping cost, duties and taxes for the instrument
to NF from another country, and NF shall pay shipping charges to return the instrument to thepurchaser.
This warranty shall not apply when corresponding to following particulars.
A) Failure caused by improper handling or use of the instrument in a manner that does notconform with the provisions of the Instruction Manual.
B) Failure or damage caused by transport, dropping, or other handling of the instrument after
purchase.
C) Failure caused by repair, adjustment, or modification of the instrument by a company,
organization, or individual not approved by NF.
D) Failure caused by abnormal voltage or the influence of equipment connected to this
instrument.
E) Failure caused by the influence of supply parts from the customer.
F) Failure caused by such as corrosion that originate in the use of causticity gas, organic
solvent, and chemical.
G) Failure caused by the insect or small animal that invaded from the outside.
H) Failure or damage caused by fire, earthquakes, flood damage, lightning, war, or otheruncontrollable accident.
I) Failure caused by the reason that was not able to be foreseen by the science andtechnology level when shipped from our company.
J) Replacement and replenishment of consumables such as batteries.

NF Corporation

WABUN: (DA00096776-003)

If there are any misplaced or missing pages, we will replace the manual. Contact thesales representative.

NOTES• Reproduction of the contents of this manual is forbidden by applicable laws.
• The contents of this manual may be revised without notice.
• Information provided in this manual is intended to be accurate and reliable.
However, we assume no responsibility for any damage regarding the contents ofthis manual.
• We assume no responsibility for influences resulting from the operations in thismanual.
Copyright 2022-2024, NF Corporation

LI5501 / LI5502 INSTRUCTION MANUALNF Corporation
6-3-20, Tsunashima Higashi, Kohoku-ku, Yokohama
223-8508 JAPAN
Phone +81-45-545-8128 Fax +81-45-545-8187

https://www.nfcorp.co.jp/

NF Corporation