I am working on a project where we need to calibrate multiple sensors at the same time. The sensors communicate through a RS485 bus (using modbus). The RS485A-signal is connected to the ADG725’s DA-pin and the RS485B-signal is connected to the ADG725’s DB-pin. Each of the SxA and SxB pairs are connected to a sensor.
A microcontroller then controls which of the connected sensors the PC “sees”.
The problem is that the RS485 signal seem to reach all of the SxA and SxB pins, meaning that each connected sensor sees the request and responds. However, only one of the sensors’ response is returned to the PC. The responding sensor corresponds to the address selected on the ADG725.
So, my questions are:
- Was I wrong to assume that the ADG725 could be used for two-way serial communication?
- If not, what could cause this issue, and what are some possible solutions?