How do I setup and wire the IC108A RS232 <--> RS485 converter?

Submitted byglx25v onFri, 08/17/2018 - 17:29

Wiring & Hardware Setup


IC108A (RS232-RS485) Converter Setup

If the Model IC108A was purchased with the Commander, the converter has been pre-set to work with the software package. If not, the following jumper/switch positions are required for proper operation of the communications link. To access the terminals and wiring, remove the top plastic cover by unscrewing the thumbscrew in the center of the bottom cover.




ITEM                    POSITION




Dip Shunt             XW1A (DCE Position)


Jumper W8      B -     C (Half Duplex)


Jumper W9      10ms     (CTS Delay)


Jumper W15    B - C


Jumper W16    A (No     turnaround delay)


Jumper W17    C     (2ms Hold)


Jumper W5      A -     B (RTS/CTS)


Switch S2            Off (Unterminated)


Switch S3            Off (No bias)





Connect an RS232 serial cable between the computer and interface converter. The IC108A requires a DB-25 (25 pin) male connector. Depending on the computer, you will either need a DB-25 female connector or a DB-9 (9 pin) female connector.


With the converter’s cover removed, locate terminal strip TB1 (near DB25 serial connector). Place a wire jumper from TXA to RXA and from TXB to RXB. Connect (1) one shielded pair cable between TXA and TXB. The other end of the wire connected to TXA should be connected to the communications A terminal on all the controls. The other end of the wire connected to the TXB terminal should be connected to the communications B terminal. Connect cable shield to earth ground at the control cabinet only.


Below summarizes the wiring to the controls:



    Converter                     Control


Jumper TXA-RXA


Jumper TXB-RXB


TXA                                  A


TXB                                  B




Note: the button on the front of the converter (Normal/DLB) must remain in “Normal” (out) position for proper operation.


Replace cover and plug in converter.