Hardware reference guide

CPU Modules
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The following figure shows SW1 and SW2.
The following table shows the SW1 and SW2 address settings.
NOTE: If "0" or an address greater than 64 is selected, the Modbus + LED will be
"on" steady, to indicate the selection of an invalid address.
Modbus Port Modem Support
Modbus Port 1 has full modem interfacing ability. Modbus Port 2 RTS/CTS
connections function properly for normal non-modem communications but do not
support modems.
Modbus Connector Pinouts
All Quantum CPUs are equipped with a 9-pin RS-232C connector that supports
Modicon’s proprietary Modbus communication protocol. The following is the Modbus
port pinout connections for 9-pin and 25-pin connections.
NOTE: Although the Modbus ports electrically support existing Modbus cables, it is
recommended that a Modbus programming cable (Part # 990NAA26320 or
990NAA26350) be used. This cable has been designed to fit under the door of a
Quantum CPU or NOM module.
Node Address SW1 SW2
1 ... 9 0 1 ... 9
10 ... 19 1 0 ... 9
20 ... 29 2 0 ... 9
30 ... 39 3 0 ... 9
40 ... 49 4 0 ... 9
50 ... 59 5 0 ... 9
60 ... 64 6 0 ... 4