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Page 64

900MB

Series

RTD/Resistance Input Module

Modbus/RS-485

Four
Discrete
Outputs
orLimit Alarms

Inputs (2)Four
RTDorResistance
Inputs

Outputs (4)Isolation

RS-485

Modbus10-36V DCor 24V ACPowerBusWorks® Modbus I/O

Inputs (2)932/934MB
Multi-Channel
Temperature
Control Modules
RTD or Resistance
Input
Limit Alarms or
Discrete Outputs
Models932MB: 2 input channels, 2 relay outputs
934MB: 4 input channels, 4 relay outputs
Input
RTD (100 ohm Pt, 120 ohm Ni, 10 ohm Cu),
Resistance (0 to 500 ohms)
OutputSolid-state relays, Form A, SPST-NO
Network Communication
Modbus-RTU high-speed RS-485
Power Requirement
10 to 36V DC,24V ACApprovals
CE marked. UL, cUL listed
Class I; Division 2; Groups A, B, C, D.

■ Description■ Special Features

This signal conditioner is a dual or quad-channel
analog input module with one discrete/relay output per input channel and a Modbus interface. It
filters and linearizes RTD or resistance inputs
while providing isolation between input, output,power, and network circuits. Lead wire compensation and upscale/downscale sensor break
detection are standard. Low voltage AC and DC
power sources are supported with nonpolarized,
diode-coupled terminals.

■

Standard Modbus RTU protocol with high-speed
RS-485 communication (up to 115K bps)■

16-bit sigma-delta A/D yields 0.1°C resolution
and 0.25°C accuracy (Pt, Ni RTDs)■

RTD linearization and sensor break detection
ensure reliable measurements■

Discrete relay outputs enable local temperature
limit alarms or host-controlled on/off switching■

Heavy-duty 1A solid-state relays provide
dependable on/off control of industrial devices■

Self-calibration lowers maintenance costs by
reducing periodic manual calibration checks■

Watchdog timers provide a configurable
failsafe output state for use when hostI/O communication is lost■

Four-way isolation eliminates potential groundloops between power, input, output andnetwork circuitry■

Self-diagnostics monitor microcontroller activity
to detect operational failures (lock-up) andexecute a reset to restore communication

The programmable inputs accommodate four
RTD types plus wide-range resistance signals.
Flexible discrete outputs operate as alarms oron/off controllers. As limit alarms, each discrete
output can be configured with high and/or low
setpoints exclusively tied to an analog input
channel. Alarm trips function without host communication enabling low-cost stand-alone alarms
as well as local backup for the primary control
system. Otherwise, on/off control is based oncommands issued by the host system.
Combining flexible transmitter functions, mixed
signal I/O, alarm support, and a network interface in a single package, makes this instrument
extremely powerful. Multi-channel design adds
cost-efficiency and allows high-density mounting.
Plus, safe, rugged construction makes thesemodules reliable for use in both control roomand distributed field I/O applications. Custom
module configurations are also possible (consultfactory for details).

Tel: 248-295-0880 e-mail: sales@acromag.com www.acromag.com
8401-003

8400100.qxp

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Modbus■ Performance■ RTD/Resistance Input

Input Ranges
Input type user-configured. Type selected applies to allchannels. RTD linearization, lead wire compensation,and open circuit or lead break detection are included.
Input Type Alpha Input Range
Accuracy
Pt 100 ohm 1.3850 -200 to 850°C ±0.25°C
Pt 100 ohm 1.3911 -200 to 850°C ±0.25°C
Ni 120 ohm 1.6720 -80 to 320°C±0.25°C
Cu 10 ohm 1.4272 -200 to 260°C ±1.00°C
Resistancelinear 0 to 500 ohms ±0.05 ohm

Resolution
Alpha
1.38501.3911
1.67201.4272linearResolution
0.1°C
0.1°C
0.1°C
0.2°C
7.8125 milliohms

Lead-Wire Compensation

Isolation

Inherent for 3-wire RTD. The maximum lead resistanceis 25 ohms per lead (Pt), 20 ohms per lead (Ni), 10ohms per lead (Cu). All lead wires must be of equal
size and length.

1500V AC for 60 seconds or 250V AC continuous.
4-way isolation between input, network, power anddiscrete I/O circuits. Inputs are isolated channel-tochannel for common mode voltage to ±5V DC.

■ Discrete Output■ Ordering
Information

Output Type
Solid-State Relay (SSR), one Form A (SPST-NO) switch
per input channel. Outputs share a common return
connection at the RTN terminals for low side switching0 to 48V DC, 1A DC.

932MB-0900
Two channel RTD/Resistance input module
934MB-0900
Four channel RTD/Resistance input module

Output ON ResistanceAccessories

Output Voltage Range

0.4 ohms maximum.

Output Response Time
4.1ms typical, from receipt of command to gate
transition of the output MOSFET.

Operation

Better than ±0.005% of input span per °C, or±1.0uV/°C, whichever is greater.

Digital outputs are set to their OFF state following asoftware or power-on reset. Outputs can be set touser-defined states following a watchdog timeout.

Noise Rejection■ Communication

Ambient Temperature EffectNormal mode: 40dB @ 60Hz, typical.
Common mode: 130dB @ 60Hz, typical.

Supported Modbus Commands

Input Filter Bandwidth-3dB at 3Hz, typical.

Input Conversion Rate
300ms per channel typical.

RTD Break Detection
Sensor failure can be configured for either upscale or
downscale. Selection applies to all channels.

The command/response protocol for communicatingwith this module adheres to the Modbus/RTU standard
for the following Modbus Functions.
Read Holding Registers
Read CoilRead Input Registers
Reset Slave
Preset Single RegisterReport Slave ID
Force Multiple Coils
Force Single Coil
Preset Multiple Register

LED Indicators
LEDs indicate power, status, and discrete level/alarm.

Excitation Current
1mA DC typical, all types.

■ Power and Isolation

Power Requirements

Optional terminal blocks: barrier strip (left) andspring clamp (right). Cage clamp terminal is standard.

10 to 36V DC (56mA max. at 24V DC).
22 to 26V AC (94mA rms max. at 24V AC).

DIGITAL OUTPUT CONNECTIONS

TB3

IN2+

LRTN

IN2INL2
IN3+
IN3INL3COMBDDA+

DIGITAL OUTPUTUP TO
48V DCNETWORKCOMMUNICATIONTB3JUMPOUT0MECHANICALRELAY INTERFACE

36 35 34 33 32 31

INL

RTN

PWR

IN-OUT1

RS485

IN+TB2

TB1/TB2RTN
OUT2TB2934MB Only

2-WIRE RTD

IN1L

RTD INPUTS 2,3

21 22 23 24 25 26

ANALOG
INPUT

IN1-

OUT3

TB4

INL

IN1+

DIG. OUT DIG. OUT

INJUMP

IN0L

932MB/934MB

ANALOG
INPUT
TB1

INL

IN+IN0-RTD INPUTS 0,1

IN-

TB1/TB2

DECADEBOX

11 12 13 14 15 16

RESISTANCE

TB1/TB2
IN+TB4TB1
IN0+

46 45 44 43 42 41

ANALOG INPUTCONNECTIONS
3-WIRE RTD900C-SIP
Configuration Software Interface Package(includes software CD-ROM for Windows,
RS-232/485 converter, and RS-485/three-wire cable)
4001-095
USB-to-RS232 adapter
TBK-B02
Optional terminal block kit, barrier strip style, 4 pcs.
TBK-S02
Optional terminal block kit, spring clamp style, 4 pcs.
PS5R-VB24
Power supply (24V DC, 2.1A)

AC/DC
POWER
10 TO 36V DC
OR 24V AC
NON-POLARIZED

OUT
RTN

TB4
OUT 3

RTN

RTN

OUT

OUT 2
DIGITAL OUTSHARES
RETURN

OUT 1
RTN
OUT 0

Tel: 248-295-0880 e-mail: sales@acromag.com www.acromag.com
8401-003

BusWorks® Modbus I/O

Input TypePt 100 ohm
Pt 100 ohm
Ni 120 ohm
Cu 10 ohm
ResistanceI/O8400100.qxp

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900MB

Series

900MB Series Technical Diagrams
TB4

TB3

Acromag

DFTB
A

DD

TB3

TB1

2.34
(59.4)

BusWorks® Modbus I/O

PWR

TB2

2 3

CL

RS485

3.75(95.3)

0 1

36 35 34 33 32 31

TB4

STCOM
COM

46 45 44 43 42 41

RUN

4.68(118.9)"T" Rail Din Mounting
Din EN 50022, 35mm

11 12 13 14 15 16

21 22 23 24 25 26

TB2

TB13.90(99.1)

1.05(26.7)
NOTE: ALL DIMENSION ARE IN INCHES (MILLIMETERS)

4.35(110.5)

PERSONAL COMPUTER
W/ WINDOWS 95/98 OR NT
RS-232 SERIAL
PORT CONNECTOR
AT BACK OF PC

PC RUNNING
ACROMAGMODBUS CONFIG
SOFTWARE

INSTALL MODBUSCONFIGURATIONSOFTWARE

RS-232 TO RS-485 CONVERTERMODEL 5034-214

CONNECT THE RS-232
SIDE OF CONVERTERTO THE PC

CAUTION: DO NOT CONNECT THE
CABLE DIRECTLY TO THE PC WITHOUTTHE CONVERTER, OR DAMAGE TO
THE MODULE MAY RESULT.

CABLE 5034-202

CONNECT THE RS-485
SIDE OF CONVERTERTO THE CABLE

900C-SIP COMMUNICATION CONNECTIONSCBACONNECT WIRES AS SHOWNCOM DTB4TB4Acromag
RUNRED

RS-485DB

BLACK

DCGREENCOM

REFER TO THE USER'S MANUALTHAT CAME WITH YOUR MODULETO COMPLETE THE MODULE'S
POWER AND I/O CONNECTIONS

TB2

TB1

COLORAPWR

ANY 900MB MODULE

TB1

R

A

STATUS LED FLASHES IN
DEFAULT MODE.

B

RS485

DDEFAULT MODE SWITCH PUSH FOR DEFAULT MODE.

D

TB33WIRE

36 35 34 33 32 31
COM

246 45 44 43 42 41

TB3COM

1RUN/PWR LED (GREEN)
STATUS LED (YELLOW)TB4STDFT0D11 12 13 14 15 1621 22 23 24 25 26

TB1

TB2

Tel: 248-295-0880 e-mail: sales@acromag.com www.acromag.com
8401-003

(This page intentionally left blank.)

Modbus

I/O■ Performance■ General■ Discrete Inputs(901 & 903 models only)
Input Type

5.6K ohm pull-up resistor SIPs are installed in sockets
at each port (four-channels per port).

I/O Pull-ups and Socket

12 active-low, buffered inputs, with a common connection. Inputs include transient suppression devices
and series connected 100K ohm resistors, plus diodeover-voltage clamps to the internal +5V supply.

Excitation (per port)

External excitation voltage for each four-channel port
is limited to 35V or less.

Supported Modbus Commands

0 to 35V DC, maximum.

Input Current

293µA, typical at 35V DC.

Input Signal Threshold

TTL compatible with 100mV of hysteresis, typical.
Low-to-High threshold is 1.7VDC, High-to-Low is
1.6VDC, typical. Limited to TTL levels of 0.8VDC(max. LOW level) and 2.0VDC (min. HIGH level).

Input Resistance

100K ohms, typical.

LED Indicators

Input Hysteresis

LEDs indicate power, status, and discrete level.

100mV DC, typical.

Power Requirements
10 to 36V DC,
22 to 26V AC.

■ Discrete Outputs(902 & 903 models only)
Output Type

12 independent, open-drain, DMOS MOSFET switcheswith a common source connection that operate as
low-side switches.

Output Voltage Range

0 to 35V DC max. (0 to 500mA/channel continuous).
External voltage source required.

Output ON Resistance
0.28 ohms maximum.

Models901MB-0900
Discrete input module
902MB-0900
Discrete output module
903MB-0900
Discrete input/output module

Accessories

900C-SIP
Configuration Software Interface Package(includes software CD-ROM for Windows,
RS-232/485 converter, and RS-485/three-wire cable)
4001-095
USB-to-RS232 adapter
TBK-B02
Optional terminal block kit, barrier strip style, 4 pcs.
TBK-S02
Optional terminal block kit, spring clamp style, 4 pcs.
PS5R-VB24
Power supply (24V DC, 2.1A)

Supply Current
Supply10V DC
24V DC
24V AC

Current Draw
130mA maximum
54mA maximum
95mA maximum

Isolation

1500V AC for 60 seconds or 250V AC continuous.
3-way isolation between I/O, network, and powercircuits.

Output Response Time

Optional terminal blocks: barrier strip (left) andspring clamp (right). Cage clamp terminal is standard.

Force Single Coil: Output updates within 250µs ofreceipt of a command.
Force Multiple Coils: First coil updates in 250µs,
followed successively by additional coils every 180µs.
DIGITAL INPUT CONNECTIONS (ACTIVE LOW)

DIGITAL OUTPUT CONNECTIONS+ 12-24V DC,

CH 3
RTN

CH 0
CH 1
CH 2
CH 3

INTERNAL INPUT
PULL-UPS ARE PRESENT

CH 7
RTN

CH 8
EXC3COMCOM
DDBA100K

TB3

TO OTHER 3CHAN OF PORTDIGITAL
I/O5-35VONOFFNETWORKCOMMUNICATION

RTN

AC/DC
POWER
10 TO 36V DC
OR 24V AC
NON-POLARIZED

TB1
EXC1OUTCH 0
DIGITAL I/O
SHARES
RETURNRTN

CH 1CH 2CH 3
RTN

RTN

Tel: 248-295-0880 e-mail: sales@acromag.com www.acromag.com

8401-003

V
I/O

902MB/903MB

TB3

EXC1CH 6CH 936 35 34 33 32 31

TB2

TB1

CH 5

PWR

RTN

CH 4

CH10

TB4

RS485

DIGITAL
I/O

EXC2

DIGITAL IN or OUT

21 22 23 24 25 26

INP
SPST
RELAY

RTN
CH11903MB shown.
901MB & 902MB
are similar.

TB2

TYPICAL

RTN

CH 2

TB1RTN

CH 1

TB4

EXC

DIGITAL
I/O

CH 046 45 44 43 42 41

INP

11 12 13 14 15 16

RTN

EXC1

DIGITAL IN or OUT

TB1
DIGITAL IN or OUT

EXC
INP

DIGITAL I/O
SHARES
RETURN

LOAD+5V+5V

INP

EXC

903MB

5V TTL LOGIC - INPUT CAN BE PULLEDUP INTERNALLY OR EXTERNALLY

BusWorks® Modbus I/O

The command/response protocol for communicatingwith this module adheres to the Modbus/RTU standard
for the following Modbus Functions.
Read Coil (Output) Status
Read Input Status
Read Holding Registers
Force Single Coil (Output)
Preset Single Register
Reset Slave
Force Multiple Coils (Outputs)
Preset Multiple Registers
Report Slave ID

Input Signal Voltage Range■ Ordering
Information

Accessories
Model 4001-095 USB-to-Serial Adapter
PERSONAL COMPUTERRUNNING WINDOWS
98/ME/2000/XP

HOSTUSBTO HOST USB PORT

USB MALE

HOST PC RUNNING
ACROMAGCONFIGURATIONSOFTWARE

4001095
USB SERIAL CONVERTERLEDRS232
DB9P

6 FEET OF CABLE

Simplifies configuration of Acromag I/O Modules ◆ Enables configuration via USB port

Description

Performance Specifications

Ordering Information

This device is a USB-to-serial adapter that you
can use to communicate with many Acromag I/O
products for setup and re-configuration for yourapplication.

USB Specification
Version 1.1
Data rate
Up to 115.2Kbps
Environmental Standards
RoHS-compliant
Basic Power Consumption
150mA
PC Requirements
Windows® 7 and newer.

NOTE: For more information visit www.acromag.com.

Key Features & Benefits■

Connects to I/O modules via USB(other adapters may be necessary)■

Complete RS232 control signals■

Conforms to USB Specification, Version 1.1■

USB-powered■

Cable length, 6 ft., UL approved

Adapters
4001-095
USB to serial adapter. Includes driver CD and manual.
5030-913
Serial port adapter. DB9S connector to RJ11 jack.
5034-202
RS-485 to 3-wire cable converter and cable, DB-9M to3 x 12AWG RS-485 cable, 8 ft.
5032-787
RS-232 to 151T transmitter configuration device
converter and cable, 6 ft.
5034-214
Non-isolated RS-232 to RS-485 Serial Port Converter,
DB-9F to DB-9F.

CablesIntelliPack 800x Series
Adapter and Cable
9-PIN CONNECTOR (DB9S)

INTELLIPACKSERIAL ADAPTER

RJ11 JACK(6 CONDUCTOR)

5030-902
Cable. 6 feet long with RJ11 plug at each end.

RJ11 PLUG(6 CONDUCTOR)MODEL 5030-902(6 feet long)

MODEL 5030-913

900MB Modbus Series
Adapter and Cable
RS232 TO RS485 SERIALCONVERTER(MODEL 5034-214)

CABLE 5034-202

RS-485

RS-2325034-202

CDB9 FEMALE

DB9 FEMALEBA

DB9 MALECOM D D

Tel: 248-295-0880 ■ sales@acromag.com ■ www.acromag.com ■ 30765 S Wixom Rd, Wixom, MI 48393 USA
Bulletin #8400-572B

All trademarks are property of their respective owners. Copyright © Acromag, Inc. 2019. Data subject to change without notice. Printed in USA 5/2019.