Imagine this: You’ve configured your RTU (Remote Terminal Unit), wired the RS485 cables, set the baud rate to 9600, and hit "Connect." Instead of flowing data, the screen flashes a cryptic red error: "Modbus Poll: Bytes Missing."
If you are at the end of a long daisy chain, ensure you have a 120-ohm resistor across the A and B lines. Without this, signal reflection can cause the tail end of a message to disappear. modbus poll bytes missing error fixed
It began with an innocuous alarm: “Modbus poll: bytes missing.” At first, it was a single register read that returned less data than expected. The SCADA screen flagged it yellow; operations shrugged and kept moving. By the next shift, red warnings bloomed across the map. Sensors with clean physical readings reported stale values, recipe steps skipped, and a packaging line slowed to a crawl. Imagine this: You’ve configured your RTU (Remote Terminal