Go to Windows Device Manager > Ports > COM Port > Advanced. Try lowering the Transmit and Receive FIFO buffers. This forces the driver to process smaller chunks of data more frequently, preventing byte loss. 5. Check Slave ID and Register Limits
If you ask for 100 registers but the slave only has 50, the slave might send an exception code or a truncated packet. modbus poll bytes missing error fixed
Here is how to troubleshoot and fix this issue once and for all. 1. Check Your Hardware Wiring (The Most Common Culprit) Go to Windows Device Manager > Ports > COM Port > Advanced
Increase this from the default (usually 1000ms) to 3000ms to see if the error clears. You’ve set up your slave ID
If you are working with RS-485, RS-232, or Ethernet-based industrial automation, few things are as frustrating as the error. You’ve set up your slave ID, matched your baud rate, and hit "Connect," only to see a communication breakdown.
Even though RS-485 is differential, a floating ground can cause enough noise to drop bytes. Ensure a signal ground wire connects all devices. 2. Adjust Timing and Timeouts
Are you using a or a Modbus TCP gateway for this setup?