I am having issues with slave devices dropping offline about once every 10-15 minutes or so. Has anyone had this similar issue and what have they done to resolve? I can see the master tx 3 times, and with no response from slave after 3rd time, it times out and goes offline, then moves on to another slave device. This happens to only 1 or 2 slave devices in a series modbus rtu circuit with about 9 slaves in series, at different time intervals. I have checked the wiring, grounding, termination resistors, comm, programming of slaves, o'scoped the signal, all these look good. Any other help would be appreciated.