Cheap USB converters often drop bytes due to buffer overflows.
What could cause such micro-interruptions? Mara’s eyes drifted to the power supply racks. They shared a route with the RS-485 bus, and last month a new VFD had been installed near Slave 12. VFDs were notorious for generating EMI if not filtered or grounded correctly. She walked the route at different times, watching the VFDs shift motor speeds as production loads changed. At moments when the VFD switched frequency, tiny spikes appeared on her oscilloscope across the bus lines. modbus poll bytes missing error fixed
Troubleshooting "Bytes Missing" in Modbus Poll: A Quick Fix Guide If you’ve been staring at a "Bytes Missing" error in Modbus Poll Cheap USB converters often drop bytes due to
Common Modbus RTU settings: 8 data bits, Even parity, 1 stop bit (8E1). If your slave uses 8N2 (No parity, 2 stop bits), the master’s frame synchronization will fail. They shared a route with the RS-485 bus,