Intermittent MODBUS RTU communication

plc

#1

Experienced intermittent comm issue between DeltaV DCS & ABB IMCS in miliseconds. trend the ‘xxxx.ST’ bit status in DeltaV system. Observed in normal condition the status value is 128 but sometime drop to 10 in miliseconds and resume to 128.
Comm settings:

  • Baud rate 38400
  • Stop bit 1, even, 8 bit