BusWorks
Model 903MB/902MB/901MB Network I/O Module User’s Manual Digital I/O
___________________________________________________________________________________________
- 2 -
Safety Summary - Symbols on equipment:
Means “Caution, refer to this manual for additional
information”.
The information contained in this manual is subject to change
without notice. Acromag, Inc., makes no warranty of any kind
with regard to this material, including, but not limited to, the
implied warranties of merchantability and fitness for a particular
purpose. Further, Acromag, Inc., assumes no responsibility for
any errors that may appear in this manual and makes no
commitment to update, or keep current, the information contained
in this manual. No part of this manual may be copied or
reproduced in any form, without the prior written consent of
Acromag, Inc.
Table of Contents
Page
1.0 INTRODUCTION
………………………………..……..
2
DESCRIPTION …………………………………………
2
Key 903MB Features………………………………..
3
ACCESSORY ITEMS ………………………………….
3
2.0 PREPARATION FOR USE
….………………………..
4
UNPACKING AND INSPECTION ……………………
4
MODULE INSTALLATION.……………..……………..
4
Default Mode Switch…………………………………
4
Pullup Installation & Removal……………………….
5
Mounting ………………………………………………
5
Electrical Connections ………………………………
5
SOFTWARE INSTALLATION ……………….………..
6
3.0 MODULE CONFIGURATION
………………………..
6
REGISTER MAP………………………………………..
6
AN INTRODUCTION TO MODBUS……………….....
8
MODULE SOFTWARE CONFIGURATION………….
15
Starting The Program…..……………………………
16
Creating A Configuration File………………………..
17
Testing Your Configuration….………………………
18
4.0 THEORY OF OPERATION
…………………………..
19
5.0 SERVICE AND REPAIR
…………………………..…
19
SERVICE AND REPAIR ASSISTANCE …………….
19
PRELIMINARY SERVICE PROCEDURE ..………….
19
TROUBLESHOOTING…………………………………
19
6.0 SPECIFICATIONS
…………………………………….
20
MODEL NUMBER DEFINITION………………………
20
I/O SPECIFICATIONS……………….…………..…….
20
ENCLOSURE/PHYSICAL SPECIFICATIONS..……..
21
APPROVALS …………………………………………..
21
ENVIRONMENTAL SPECIFICATIONS….…………..
21
COMMUNICATION INTERFACE SPECIFICATIONS
22
CONFIGURATION AND CONTROLS..……………...
22
SOFTWARE CONFIGURATION……..…………….…
22
List of Drawings
Page
Simplified Schematic (4501-809)…..…….……………..…
24
Functional Block Diagram (4501-810)………………….…
24
Pullup Resistor SIP Locations (4501-811)………………..
25
Network Connections (4501-805)…………..…….……….
25
Electrical Connections Page 1 of 4 (4501-813)……..…...
26
Electrical Connections Page 2 of 4 (4501-813)……..…...
26
Electrical Connections Page 3 of 4 (4501-813)……..…...
27
Electrical Connections Page 4 of 4 (4501-813)……..…...
27
Interposing Relay Conn. & Contact Pro. (4501-814)…….
28
Enclosure Dimensions (4501-815) …………………..……
28
Windows 95/98 & NT are registered trademarks of Microsoft
Corporation. Modbus is a registered trademark of Modicon, Inc.
IMPORTANT SAFETY CONSIDERATIONS
It is very important for the user to consider the possible adverse
effects of power, wiring, component, sensor, or software failures
in designing any type of control or monitoring system. This is
especially important where economic property loss or human life
is involved. It is important that the user employ satisfactory
overall system design. It is agreed between the Buyer and
Acromag, that this is the Buyer's responsibility.
1.0 INTRODUCTION
These instructions cover the hardware functionality of the
transmitter models listed in Table 1. Supplementary sheets are
attached for units with special options or features.
Table 1: Models Covered in This Manual
Series/
Input Type
-Options/Output/
Enclosure/ Approvals
1
-Factory
Config
2
I/O Type
901MB
-0900
-C
12 Inputs
902MB
-0900
-C
12 Outputs
903MB
-0900
-C
12 In/Out
Notes (Table 1):
1. Agency approvals include CE, UL Listed, and cUL Listed.
2. Include the “-C” suffix to specify factory configuration option.
Otherwise, no suffix is required for standard configuration.
3. The 903MB includes both inputs and outputs, while the
902MB is output only, and the 901MB is input only.
The same circuit board is used to build all three models
listed. The fully populated 903MB model includes tandem input
and output circuits. Input circuitry is removed for 902MB models
which are output only, and output circuitry is removed for 901MB
models which are input only.
DESCRIPTION
The Acromag 900MB family is a group of process I/O
modules and accessories for Modbus/RS485 network I/O
applications. The 901MB/902MB/903MB models support up to
twelve buffered inputs and/or open-drain outputs according to the
model number. Inputs are active-low and outputs are current-
sinking low-side switches. These models are the complement of
Acromag 904MB/905MB/906MB modules which have open-
source high-side output switches and active-high inputs. The
900MB modules contain an advanced technology microcontroller
with integrated downloadable flash memory and EEPROM for
non-volatile program, configuration, and parameter data storage.
Units are fully reconfigurable via our user-friendly Windows
95/98
or NT
Configuration Program and the RS485 interface.
Once configured, these modules may operate as active RS485
network slaves connected to other modules and a host computer
performing network I/O functions.
The Model 901MB supports up to 12 digital inputs. The
Model 902MB drives up to 12 digital outputs. The Model 903MB
supports up to 12 tandem digital input and output channels.
Each 900MB module provides an isolated RS485 network I/O
path utilizing the Modbus protocol. Socketed I/O pullup resistors
are installed and pull the I/O channels up to the EXC+ terminal.
These resistors may be easily removed or exchanged according
to your application requirements.
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