ICS Advent PCI-ICOM485/4, Product Manual

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Manual Number: 00650-148-1 Page 9
Chapter 3: Option Selection
To help you locate the jumpers described in this section, refer to the Option Selection Map at the
end of this section. Operation of the serial communications section is determined by jumper instal-
lation as described in the following paragraphs.
Terminations
A transmission line should be terminated at the receiving end in its characteristic impedance.Installing
a jumper at the locations labeled LDxO applies a 120W load across the transmit/receive input/
output for RS-485 operation.
Simplified Termination Schematic
In RS-485 operations where there are multiple terminals, only the RS-485 ports at each end of the
network should have terminating impedance as described above. To so terminate the COM A port,
place a jumper at the location labeled LDAO. To terminate the COM B, COM C, and COM D
ports, place jumpers at locations labeled LDBO, LDCO, and LDDO respectively.
Also, for RS-485 operation, there must be a bias on the RX+ and RX- lines. If the PCI-ICOM485/
4 (/2) card is not to provide that bias, contact the factory technical support.
Data Cable Wiring- 37 Pin Connector
Signal Connector Pin Signal Connector Pin
COMA Tx+/Rx+ 37 COMC Tx+/Rx+ 27
COMA Tx-/Rx- 19 COMC Tx-/Rx- 9
COMA Gnd 18 COM C Gnd 8
COMB Tx+/Rx+ 32 COMD Tx+/R/X+ 21
COMB Tx-/Rx- 14 COMD Tx-/Rx- 3
COMB Gnd 13 COMD Gnd 2