The rs485 chip uses ti's SN75176, both A/B ports have signal input, and R has no signal output. Why can't the signal be received?
Gael ポストする September 23, 2020
Try to check the control terminal and ab wiring and signal level difference.
Bobby ポストする September 23, 2020
First, check if there is a signal on the data line.
Brett ポストする September 23, 2020
Look at the circuit diagram again. If there is a signal, the circuit may have a problem.
