Issue
What is the pin configuration for Modbus RTU when using a 9 pin comm port on a BCX controller.
Environment
- BCX
- Modbus RTU
Cause
Connecting a BCX or CX controller to a Modbus RTU device.
Resolution
RS232 connection for a 9 pin BCX comm port.
BCX Comm 1 (9 Pin) RJ 45 Connector @ Modbus device
- Pin 1 CXD --> Pin 1 DTR
- Pin 7 RTS --> Pin 2 CTS
- Pin 4 DTR --> Pin 3 CXD
- Pin 8 CTS --> Pin 4 RTS
- Pin 5 GND --> Pin 5 GND
- Pin 3 TD --> Pin 6 RD
- Pin 6 DSR --> Pin 7 DSR
- Pin 2 RD --> Pin 8 TD