Instruction Manual

6.3 RS-232/485 ITB-PLC CABLES
A custom RS-232 cable is required for point-to-point connection from the RS-232/485 ITB J1 to the
PLC. The recommended cable for this PLC application is illustrated in Figure 6-3. In the figure,
one end of the cable has a nine pin male plug that connects to J1 of the RS-232/485 ITB and the
other end has a 25 pin male or female plug as required by the PLC.
For multidrop installations, the standard four wire bundle with shield is used to connect TB2 of the
RS-232/485 board to the Modbus PLC RS-422 input. The TB2 lug connections are illustrated in
Figure 6-4. The maximum cable length for RS-485 (422) is 4000 feet (1219 m).
RS-232/485 ITB, J1 MODBUS PLC
(FEMALE DB-9 (MALE/FEMALE, DB-25
CABLE END) CABLE END)
(MODEL 884
MODBUS PLC)
RxD (IN) 2 2 TxD
TxD (OUT) 3 3 RxD
GND 5 7 GND
74 RTS
85 CTS
6 DSR
20 DTR
(USED WITH MODBUS POINT-TO-POINT INSTALLATIONS)
Figure 6-3. RS-232/485 ITB J1 to Modbus PLC Cable
RS-232/485 ITB TB2 MODBUS
CONNECTION CONNECTION
RECEIVE (R-) 1 TRANSMIT (T-)
RECEIVE (R+) 2 TRANSMIT (T+)
TRANSMIT (T-) 3 RECEIVE (R-)
TRANSMIT (T+) 4 RECEIVE (R+)
SHIELD 5 GROUND
(USED WITH MODBUS MULTIDROP INSTALLATIONS)
Figure 6-4. RS-232/485 ITB TB2 to Modbus PLC Cable
53MC9015 53MC5000 PLC and Printer Interfaces
6-2
MODBUS2