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:
Jan 01, 2024