ModbusRTUClient.requestFrom can lead to bus collisions

[cheetor5923]

Not exactly sure if this qualifies. I have a loop that steps through reading a bunch of inputs. The first run through works perfectly I do one requestFrom() and then process the resulting data then the loop pops onto it's next iteration and tries to take over the RS-485 bus while the server is still in TX mode, corrupting the first few bits of the request... the library doesn't generate the necessary 3.5 character wait time.

[crashkopf]

I've been having the same issue. Libmodbus does not enforce the wait time after receiving before sending again. It causes communication errors with some devices when polling at maximum rate. There's a pull request to fix it upstream. https://github.com/stephane/libmodbus/pull/494/commits/6c9c575d169a9919c95a0db218434c89386681e9

I have not yet tried running a patched libmodbus with this library.