PC104-AC5
DIGITAL I/O
User’s Manual

Revision 1A
October, 2000

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+03&$&OZSTable of Contents
1 INTRODUCTION................................. 1
2 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.1 BASE ADDRESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.2 WAIT STATE SELECT (P3) . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 IRQ IN/ +5V SELECT (P4) . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.4 INTERRUPT LEVEL SELECT (P5) . . . . . . . . . . . . . . . . . . . 3
2.5 INSTALLING THE BOARD . . . . . . . . . . . . . . . . . . . . . . . . 3
2.6 CONNECTOR DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 REGISTER ARCHITECTURE . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 DIGITAL DATA REGISTERS . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 CONTROL REGISTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5 ELECTRONICS AND INTERFACING . . . . . . . . . . . . . . . . . 12
5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2 PULL UP & PULL DOWN RESISTORS . . . . . . . . . . . . . . 12
5.3 TTL TO SOLID STATE RELAYS . . . . . . . . . . . . . . . . . . . 14
5.4 VOLTAGE DIVIDERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.5 LOW PASS FILTERS DE-BOUNCE INPUTS . . . . . . . . . . 16

This page is blank.

1 INTRODUCTION
The PC104-AC5 is a 24-line digital I/O board. The control register which sets the
direction of the I/O ports is identical to an 8255 in mode 0 (see 8255 data sheet). The
I/O pins are high-drive TTL compatible.
The connector is a 50-pin header which is compatible with the pin-out of OPTO-22
and GORDOS solid state relay racks. If you are using an OPTO or GORDOS form
factor solid state relay rack, the PC104-AC5 can be connected directly to the relay
rack through a 50-pin cable such as the C50FE-2.
A group of application notes is included to assist in electrical interfacing.

2 INSTALLATION
Before you open your computer and install the board, install and run InstaCal, theinstallation, calibration and test utility included with your board. InstaCal will guide
you through switch and jumper settings for your board. Detailed information
regarding these settings can be found below. Refer to the Extended Software
Installation manual for InstaCal installation instructions.
The PC104-AC5 has one bank of base address-select switches, an interrupt selectjumper, a wait state select jumper and a jumper for configuring the function of pin 49
which must be set before
installing the board in yourcomputer.
9 8 7 6 5 4 3 22 Sw Hex

A9 200A8 100
A7 80
A6 40
A2 04
A5
20
A4 10
A3 8
A2 4

2.1 BASE ADDRESS
On the base address switches,(Figure 2-1),
each switch
position corresponds to one of
the PC bus address lines. By
placing the switch down, theaddress decode logic responds tothat address bit.

Figure 2-1. Base Address Switch - 300h Shown
1A complete address is constructed by calculating the HEX or decimal number whichcorresponds to all the address bits the board has been instructed to respond to. For
example, in Figure 2-1, switches 9 and 8 are DOWN, all others UP.
Using figure 2-1 as an example, address 9 = 200h (512D) and address 8 = 100h
(256D); added together they equal 300h (768D).
Certain address are used by the PC, others are free and may be used by thePC104-AC5 and other expansion boards. We recommend BASE = 300h (768D) be
tried first.
2.1.1 I/O Addresses
The BASE switch may be set for an address in the range of 000-3FC so it should not
be hard to find a free address area for your board. If you are not using IBM
prototyping cards or some other board which occupies these addresses, 300-31Fh arefree to use. Refer to Table 2-1.
Addresses not specifically listed, such as 390-39Fh, are free.
Table 2-1. Computer I/O Addresses
HEX
RANGE
000-00F
020-021040-043060-063060-064070-071080-08F
0A0-0A1
0A0-0AF
0C0-0DF
0F0-0FF
1F0-1FF
200-20F
210-21F
238-23B
23C-23F
270-27F
2B0-2BF

FUNCTION
8237 DMA #1
8259 PIC #1
8253 TIMER
82C55 PPI (XT)8742 CONTROLLER (AT)
CMOS RAM & NMI MASK
(AT) CARDDMA PAGE REGISTERS
8259 PIC#2
NMI MASK (XT)8237 #2 (AT)80287 NUMERIC CO-P (AT)HARD DISK (AT)GAME CONTROLEXPANSION UNIT (XT)BUS MOUSEALT BUS MOUSEPARALLEL PRINTER
EGA
2

HEX
RANGE
2C0-2CF
2D0-2CF
2E0-2E7
2E8-2EF
2F8-2FF
300-30F

FUNCTION
EGA
EGA
GPIB (AT)SERIAL PORTSERIAL PORTPROTOTYPE

310-31F
320-32F
378-37F
380-38F
3A0-3AF
3B0-3BB
3BC-3BF
3C0-3CF
3D0-3DF
3E8-3EF
3F0-3F7
3F8-3FF

PROTOTYPE CARD
HARD DISK (XT)
PARALLEL PRINTER
SDLC
SDLC
MDA
PARALLEL PRINTEREGACGASERIAL PORTFLOPPY DISKSERIAL PORT

2.2 WAIT STATE SELECT (P3)
A wait state may be enabled on the PC104-AC5 by selecting the ON position ofheader P3. Enabling the wait state decreases the PC’s bus transfer rate during I/Oreads or I/O writes to the PC104-AC5. The wait state may be necessary for situations
where the PC’s I/O transfer rate is too fast for the PC104-AC5, causing the board to
randomly fail. If this is the case the jumper should be placed in the ON position. The
factory default location is OFF.

2.3 IRQ IN/ +5V SELECT (P4)The PC104-AC5’s header P4 provides the option of routing either +5V or an
externally generated interrupt to pin 49 of the 50-pin connector P1. The +5V option
may be used in applications that require the PC104-AC5 to provide +5V power toaccessory boards connected to P1. The IRQ position may be used for applications
where an external interrupt needs to be passed to the PC104-AC5 which is then passed
to PC. The particular interrupt level to be used can be selected using header P5 (seesection 2.4).

CAUTIONBe sure to place jumper P4 in the correct position for your application. When thejumper is in the 5V position, it supplies 5VDC to pin 49. If pin 49 is connected to an
external circuit that is not a 5VDC power input, it may damage the external circuit orthis board.

2.4 INTERRUPT LEVEL SELECT (P5)
The interrupt jumper needs to be set only if the software you are using requires it. The
PC104-AC5 provides interrupt levels 2 to 7 when using jumper-selectable header P5.
If you do set the interrupt jumper to a value other than X (no interrupt), please checkyour PC’s current configuration for possible interrupt conflicts. The factory default
setting is no interrupt (P5, position X).

2.5 INSTALLING THE BOARD
1. Turn the power off.

3

2. Remove the cover of your computer. Please be careful not to dislodge any of thecables installed on the boards in your computer as you slide the cover off.
3. If desired, install plastic standoffs on board.
4. Install the board firmly in the extension jack.

2.6 CONNECTOR DIAGRAM
The PC104-AC5 I/O uses a 50-pin header-type connector. The signals available are
direct connections to an 82C55 digital I/O integrated circuit. Figure 2-2 shows the pinouts for the connector.
PORT C7 1
PORT C6 3
PORT C5 5PORT C4 7
PORT C3 9
PORT C2 11
PORT C1 13
PORT C0 15
PORT B7 17
PORT B6 19
PORT B5 21
PORT B4 23
PORT B3 25
PORT B2 27
PORT B1 29
PORT B0 31
PORT A7 33
PORT A6 35
PORT A5 37
PORT A4 39
PORT A3 41
PORT A2 43
PORT A1 45
PORT A0 47
IRQ IN OR 5VDC 49

2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50

Figure 2-2. Digital Connector Pin Out
CAUTIONBe sure to place jumper P4 in the correct position for your application. Whenthe jumper is in the 5V position, it supplies 5VDC to pin 49. If pin 49 isconnected to an external circuit that is not a 5VDC power input, it may damage
the external circuit or this board.

4

This board is typically used for driving the SSR-PB24 solid state relay rack. For thisapplication, the C50FE-# cable is used.
If your application requires point to point wiring, you may want to consider the
C50FF-# cable and a screw terminal board to simplify connections to the PC104-AC5.
Please refer to the information on the CIO-TERM100, CIO-SPADE50 and
CIO-MINI50 screw terminal boards or the SCB-50 and SCB-100 screw terminal
boards and enclosure.

5

3 REGISTER ARCHITECTURE

3.1 INTRODUCTION
The PC104-AC5 contains three data and one control register for the 24 lines of digital
I/O.
The first address, or BASE ADDRESS, is determined by setting a bank of switches on
the board.
Register manipulation is best left to experienced programmers as most of thePC104-AC5 functions are implemented in the easy to use Universal Library.
The register descriptions follow all follow the format:
7
A7

6
A6

5
A5

4
A4

3
A3

2
A2

1
A1

0
A0

Where the numbers along the top row are the bit positions within the 8-bit byte andthe numbers and symbols in the bottom row are the functions associated with that bit.
To write to or read from a register in decimal or HEX, the following weights apply:
BIT POSITION
0
1
2
3
4
5
6
7

DECIMAL VALUE
1
2
4
8
16
32
64
128

HEX VALUE
1
2
4
8
10
20
40
80

To write a control word or data to a register, the individual bits must be set to 0 or 1
then combined to form a byte.
The method of programming required to set/read bits from bytes is beyond the scopeof this manual.

6

In summary form, the registers and their function are listed on the following table.
Within each register are eight bits which may constitute a byte of data or eightindividual bit set/read functions.

ADDRESS
BASE +0
BASE +1
BASE +2
BASE +3

Table 3-1. Board Register Functions
READ FUNCTIONWRITE FUNCTION
1st Port A Input
1st Port A Output
1st Port B Input
1st Port B Output
1st Port C Input
1st Port C Output
None.
Configure I/O

3.2 DIGITAL DATA REGISTERSPort A
Base Address + 0
7
6
A7
A6

5
A5

4
A4

3
A3

2
A2

1
A1

0
A0

Port B Data
Base Address +1
7
6
B7
B6

5
B5

4
B4

3
B3

2
B2

1
B1

0
B0

Ports A & B may be programmed as input or output. Each is written to and read fromin bytes, but for control and monitoring, use individual bits.
When using bit set/reset and bit read functions, unwanted bits must be masked out ofreads and ORed into writes.
Port C Data
Base Address +2
7
6
C7
C6
CH3
CH2

5
C5
CH1

4
C4
CH0

3
C3
CL3

2
C2
CL2

1
C1
CL1

0
C0
CL0

Port C may be used as one 8-bit port of either input or output, or it may be split into
two 4-bit ports which may be independently input or output. The notation for theupper 4-bit port is CH3 - CH0, and for the lower, CL3 - CL0.
Although it may be split, every read and write to port C carries eight bits of data so
unwanted information must be ANDed out of reads, and writes must be ORed with thecurrent status of the other port.
7

3.2.1 Output Ports
Ports configured for output hold the output data written to them. This output byte canbe read back by reading a port configured for output.
IMPORTANT NOTETHIS BOARD EMULATES THE 82C55. WHENEVER A
82C55 IS POWERED ON OR RESET, ALL PINS ARE SETTO HIGH IMPEDANCE INPUT. SO DOES OUREMULATION.
The implications of this is that if you have output devices such as solid state relays,
they may be switched on whenever the computer is powered on or reset. To prevent
unwanted switching and to drive all outputs to a known state after power on or reset,
pull all pins either high or low through a 10K resistor.
To install pull up/down resistor packs, see the application note.
3.2.2 Input Ports
In 82C55 mode 0 configuration, ports configured for input read the state of the input
lines at the moment the read is executed, transitions are not latched.

3.3 CONTROL REGISTER
Configure A, B & C
Base Address +3
7
6
N/A
N/A

5
4
N/A
A
Group A

3
CU

2
N/A

1
B
Group B0
CL

The Ports A, B, C High and C Low may be independently programmed for input or
output. The most commonly used mode for an 82C55 is mode 0, input / output mode.
This is the only mode supported by the PC104-AC5. The codes for programming theemulated 82C55 in this mode are shown in Table 3-2.
NOTE: D7 is always 1 and D6, D5 & D2 are always 0.

8

D4
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1

Table 3-2. 82C55 Emulation Programming Codes - Mode 0
D3
D1
D0
HEX DEC
A
CU
B
0
0
0
80
128
OUT OUT OUT
0
0
1
81
129
OUT OUT OUT
0
1
0
82
130
OUT OUT
IN
0
1
1
83
131
OUT OUT
IN
1
0
0
88
136
OUT
IN
OUT
1
0
1
89
137
OUT
IN
OUT
1
1
0
8A
138
OUT
IN
IN
1
1
1
8B
139
OUT
IN
IN
0
0
0
90
144
IN
OUT OUT
0
0
1
91
145
IN
OUT OUT
0
1
0
92
146
IN
OUT
IN
0
1
1
93
147
IN
OUT
IN
1
0
0
98
152
IN
IN
OUT
1
0
1
99
153
IN
IN
OUT
1
1
0
9A
154
IN
IN
IN
1
1
1
9B
155
IN
IN
IN

9

CL
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN

4 SPECIFICATIONS
Typical for 25°C unless otherwise specified.

Power consumption+5V Operating
PC104-AC5

625 mA typical, 960 mA max

Digital Input / Output
Digital type
Number of I/O
Configuration

Input low voltage
Input high voltage
Output low voltage
Output high voltage
High Level Output Current
Low Level Output Current
Absolute maximum input voltage
Pull-Up/Pull-Down Resistors
Power On / Reset

Digital Outputs - 74S244
Digital Inputs - 74LS373
24
2 banks of 8 bits each and 2 banks of 4 bits
each (8255A mode 0 emulation)
Each bank programmable as either input or
output
0.8V max.
2.0V min.
0.5V max. (Iol = 64 mA)
2.4V min. (Ioh = −15 mA)−15 mA max.
64 mA max.
+5.5V max.
Locations provided for user-installation.
High impedanceInterrupts
Interrupt Source
Interrupt Levels
Interrupt enable/disable

External
2, 3, 4, 5, 6, 7 (jumper-selectable)
Jumper-selectable (P4)

Environmental
Operating Temperature Range
Storage Temperature Range
Humidity

0 to 70°C−40 to 100°C
0 to 95% non-condensing

10Mechanical
Card dimensions

103mm wide x 96mm long x 15mm thickConnector and Pin Out
Connector

Pin
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49

50-pin. Compatible with SSR-PB24 using
C50FE-x cable

Signal Name
PORT C – B7
PORT C – B6
PORT C – B5
PORT C – B4
PORT C – B3
PORT C – B2
PORT C – B1
PORT C – B0
PORT B – B7
PORT B – B6
PORT B – B5
PORT B – B4
PORT B – B3
PORT B – B2
PORT B – B1
PORT B – B0
PORT A – B7
PORT A – B6
PORT A – B5
PORT A – B4
PORT A – B3
PORT A – B2
PORT A – B1
PORT A – B0
IRQ IN OR +5V Out(jumper-selectable)
See CAUTION Page 4

Pin
2
4
6
8
10
12
14
16
18
20
22
24
26
28
20
32
34
36
38
40
42
44
46
48
50

11

Signal Name
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND

5 ELECTRONICS AND INTERFACING

5.1 INTRODUCTION
This short introduction to the electronics most often needed by digital I/O board users
covers the following topics:
y
y
y
y
y
y
y

Pull up/pull down resistors
Transistors
Power MOSFETs
Solid State Relays
Voltage Dividers
Low Pass Filters for digital inputs
Noise; sources and solutions
IMPORTANT NOTEThis board emulates the 82C55. WHENEVER THE 82C55 IS
POWERED ON OR RESET, ALL PINS ARE SET TO HIGHIMPEDANCE INPUT.

The implications of this fact is that if you have output devices such as solid state
relays, they may be switched on whenever the computer is powered on or reset. To
prevent unwanted switching and to drive all outputs to a known state after power on or
reset, pull all pins either high or low through a 2.2K resistor.
To install pull up/down resistor packs, see the application note.

5.2 PULL UP & PULL DOWN RESISTORSThis description deals with pull up/down resistors and the emulated 82C55 digital I/O.
Whenever the PC104-AC5 is powered on or reset, the control register is set to a
known state. That state is mode 0, all ports are inputs.
When used as an output device to control other TTL input devices, the PC104-AC5
applies a voltage level of 0V for low and 2.5V to 5V for high.
12The concept of voltage level of a PC104-AC5 in input mode is meaningless. Do notconnect a volt meter to the floating input of an PC104-AC5. It will show you nothingof meaning. In input mode the PC104-AC5 is in 'high Z' or high impedance. If your
PC104-AC5 was connected to another input chip (the device you were controlling),
the inputs of that chip are left floating whenever the PC104-AC5 is in input mode.
If the inputs of the device you are controlling are left to float, they may float up or
down. Which way they float is dependent on the characteristics of the circuit and theelectrical environment; and is unpredictable This is why it often appears that thePC104-AC5 has gone 'high' after power up. The result is that the controlled device
gets turned on.
That is why you need pull up/down
resistors.

8 2 C 5 5E m u la t e d
C ir c u itShown here is one PC104-AC5
digital output with a pull-up
resistor attached.
The pull-up resistor provides areference to +5V while its value of
2200 ohms allows only about 2 mA
to flow through the circuit.
If the PC104-AC5 is reset and enters high impedance input, the line is pulled high. At
that point, both the PC104-AC5 AND the device being controlled will sense a highsignal.
If the PC104-AC5 is in output mode, the PC104-AC5 has more than enough power toover ride the pull-up/down resistor's high signal and drive the line to 0 volts. If thePC104-AC5 asserts a high signal, the pull up resistor guarantees that the line goes to+5V.
A pull-down resistor accomplishes the same task except that the line is pulled low
when the PC104-AC5 is reset. The board has more than enough power to drive theline high.
The PC104-AC5 board is equipped with positions for pull-up/down resistors Single
Inline Packages (SIPs). The positions are marked RN1 (Port A), RN2 (Port B) andRN3 (Port C) and are located beside the connector P1.

13

A 2.2Kohm, eight-resistor SIP has all its resistors connected on one end to a single
common pin. The common pin is marked with a dot and is at one end of the SIP. The
other resistor ends connect to eight in-line pins.
There are three locations for installation of SIP resistors on the PC104-AC5. They aremarked RN1 through RN3. The SIP can be installed to pull-up or pull-down. At eachlocation, RN1, 2, and 3, there are 10 holes in a line. On one end of the line a hole ismarked HI; the other end LO. The eight holes in the middle are connected to the eightlines of a port, A, B, or C.
To pull-up all eight lines, orient the SIP with the common pin (dot) in the HI hole end;
to pull-down, install the resistor with the common pin in the LO hole.
Carefully solder the SIP in place.
A 2.2K resistor SIP is recommended. Use other values only if you have calculated thenecessity of doing so.

5.3 TTL TO SOLID STATE RELAYS
Many applications require digital outputs to switch AC and DC voltage motors on andoff and to monitor AC and DC voltages. High voltages cannot be controlled or readdirectly by the TTL digital lines of a PC104-AC5.
Solid State Relays, such as those available from Measurement Computing Corp.
allow control and monitoring of AC and high DC voltages and provide 750V
isolation. Solid State Relays (SSRs) are the recommended method of interfacing to
AC and high DC signals.
The most convenient way to use solid state relays and a PC104-AC5 board is to use a
Solid State Relay Rack. A SSR Rack circuit board has output buffers to switch thesocketed SSRs.
SSR Racks are available from Measurement Computing Corp.

5.4 VOLTAGE DIVIDERS
To measure a signal greater than the input range of a digital input, use a voltage
divider to drop the voltage of the input to the level the board can safely accept.

14

In a voltage divider, the voltage
across one of the resistors in acircuit is proportional to that
resistance divided into the total
resistance in the circuit.
The object is to choose tworesistors with the proper ratio
relative to the full scale of thedigital input and the maximum
signal voltage.
For
droppingthevoltageproportionally (attenuation)
theformula for is:

Attenuation = R1+R2
R2

2 = 10K+10K
10K

R1=(A-1)*R2

The variable Attenuation is the proportional difference
between the signal voltage max and the full scale of theanalog input.
For example, if the signal varies between 0 and 20 voltsand you wish to measure that with an analog input with afull scale range of 0 to 10 volts, the Attenuation is 2:1 orjust 2.
For a given attentuation, pick a handy resistor and call it
R2, then use this formula to calculate R1.

Digital inputs also may require voltage dividers. For example, if you wish to input a
24 volt digital signal, you cannot connect that directly to the PC104-AC5 digital
inputs. The voltage must be dropped to 5 volts max. The Attenuation is 24:5 or 4.8.
Use the equation above to find an appropriate R1 if R2 is 1K. Remember that a TTL
input is 'on' when the input voltage is greater than 2.5 volts.

IMPORTANT NOTE
The resistors, R1 and R2, are going to dissipate all the power in thedivider circuit according to the equation Current = Voltage /Resistance and power = current-squared times resistance. The
higher the value of the resistance (R1 + R2) the less power
dissipated by the divider circuit. Here is a simple rule:15

For Attenuation of 5:1 or less, no resistor should be less than 10K.
For Attenuation of greater than 5:1, no resistor should be less than 1K.
The CIO-TERMINAL has the circuitry on board to create custom voltage dividers. It
is a 16" by 4" screw terminal board with two 37-pin, D-type connectors and 56 screw
terminals (12 - 22 AWG). Designed for table top, wall, or rack mounting, the board
provides prototype, divider circuit, filter circuit and pull-up resistor positions which
you can use for your application.

5.5 LOW PASS FILTERS DE-BOUNCE INPUTS
A low-pass filter between a signal source and an A/D board attenuates higher than the
cut-off frequency, preventing them from entering the A/D board's analog or digital
input circuits.
The key term in a low pass filter circuit is cut-off frequency. The cut-off frequency isthat frequency above which no variation of voltage with respect to time may enter thecircuit. For example, if a low pass filter had a cut-off frequency of 30 Hz, the kind ofinterference associated with line voltage (60 Hz) would be largely filtered out but asignal of 25 Hz would pass.
Low-pass filters are often used to remove a switch-bounce noise signal from a switch
closure. The signal can be complex and have quite high frequency components
requiring a more sophisticated filter.
A simple low-pass filter can beconstructed from one resistor (R)and one capacitor (C). The cut off
frequency is determined according
to the formula:

SignalHigh

A/D BoardHigh Input

R

C
Signal
Volts

Fc =

1
2*Pi*R*CR=

1
2*Pi*C*Fc

SignalLow
LOW PASS FILTER - Fc =Where Pi = 3.14...
R is in Ohms
C is in Farads
Fc is in cycles per second.
16

A/D Board
Low Input
1
2*Pi*R*CFor your notes.

17

For your notes.

18

EC Declaration of Conformity
We, Measurement Computing Corp., declare under sole responsibility, that the
product:
PC104-AC5
Part Number

Digital I/O Board
Description

to which this declaration relates, meets the essential requirements, is in conformity
with, and CE marking has been applied according to the relevant EC Directives listed
below using the relevant section of the following EC standards and other normative
documents:
EU EMC Directive 89/336/EEC: Essential requirements relating to electromagnetic
compatibility.
EU 55022 Class B: Limits and methods of measurements of radio interference
characteristics of information technology equipment.
EN 50082-1: EC generic immunity requirements.
IEC 801-2: Electrostatic discharge requirements for industrial process measurement
and control equipment.
IEC 801-3: Radiated electromagnetic field requirements for industrial process
measurements and control equipment.
IEC 801-4: Electrically fast transients for industrial process measurement and control
equipment.

Carl Haapaoja, Director of Quality Assurance

Measurement Computing Corporation
10 Commerce Way
Suite 1008
Norton, Massachusetts 02766(508) 946-5100
Fax: (508) 946-9500
E-mail: info@mccdaq.com
www.mccdaq.com