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154
CMC TECHNICAL REFERENCE MANUAL
1X36003 Version 2.52
1996-1999 Ingersoll-Rand Company
Date of Issue: 18-Oct-1999
RS422 Network Wiring Diagram - Half Duplex
Tx+ Tx- Rx+ Rx- Gnd
RS-232
DB-9
DL+ DL- Gnd
RS-422/485
RS-485
24+
Power
A0
A1
Universal Communication Module (UCM
)
IMPORTANT: Because this is the first slave node in the Modbus
network, the transmit and receive lines of this node are crossed with
the transmit and receive lines of the Modbus Master.
Gnd
To
BCM
To
Power
Supply
Compressor Panel #1
RS-232
DB-9
DL+ DL- Gnd
RS-422/485
RS-485
24+
Power
A0
A1
Universal Communication Module (UCM
)
Gnd
T o
BCM
To
Power
Supply
Compressor Panel #2
Tx+ Tx- Rx+ Rx- Gnd
Tx+
Tx-
Rx+
Rx-
ICC-11
RS-232C to RS-422
Interface Converter
SW1 - DCE
SW2 - Simulation Mode
SW3 - Position 1, Tx
enabled when RTS ON,
RX enabled when RTS Off
120 VAC
RS-232
DB-25
Modbus Master
From
Computer
Serial Port
RS-232
Compressor Panel #3
Compressor Panel #4
Compressor Panel #5
Compressor Panel #6
Compressor Panel #n
The maximum
distance of a
MODBUS Network is
4000 electrical feet;
i.e., the length of the
wire from the RS-232
to RS-422 Converter
(Location A) to the last
compressor's
Universal
Communication
Module (Location B).
The maximum number
of devices (nodes) on
a MODBUS Network is
30. (For CEM for
Windows and a CMC
only system, the
maximum is 16).
A terminating resistor
is not required at the
end of the network.
A
120 VAC
Modbus Address - 01
(Set through software)
Modbus Address - 02
(Set through software)
Modbus Address - 03
IRBUS Address - any
Modbus Address - 04
IRBUS Address - any
Modbus Address - 05
IRBUS Address - any
Modbus Address - 06
IRBUS Address - any
Modbus Address - nn
IRBUS Address - any
IRBUS Address
Set switch A0: 0-F
Set switch A1: 0
RS-422
Twisted Pair Wires
with Ground (3 Wires)
RS-422
Twisted Pair
Wires with
Ground (3
Wires)
RS-422
Twisted
Pair Wires
(2 Wires)
IRBUS Address
Set switch A0: 0-F
Set switch A1: 0
B
NOTE:
Ground wire should be connected
at one ground location only.