Wiring to terminal block by cutting DB9 cable

How do you wire RS232 or RS485 radio modems to a terminal block when the signals are available only on the DB9 connector?

The easiest method is to cut the DB9 straight through serial cable supplied with the PKG-R radio modem and strip the wires inside to connect them to the terminal block directly.

Caution:

The individual wires inside the DB9 cable are small diameter stranded wires and may break off. It is not recommend that this cable be used in a vibration or movement prone environment because of the risk of breaking the wires. Use the DB9 to RJ45 adaptors instead (search knowledge base).

For convenience here is a table showing  the wires inside the DB9 cable and which signals they are connected to in different modes of operation.

DB9 Pin   RS232 (DCE) RS485 4-wire RS485 2-wire
1   DCD    
2   RXD TX- T/R- (A)
3   TXD RX-  
4   DTR    
5   GND GND  
6   DSR    
7   RTS RX+  
8   CTS TX+ T/R + (B)
9   PWR*(RI) PWR* PWR*

*Optionallly provide power to radio through Pin 9 of DB9 (DB0 pin 9 is connected to center (positive) lead of power jack)

Last updated: Aug 23, 2017

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RF

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