ESP32 Forum

Using the official TCP Modbus https://docs.espressif.com/projects/esp ... pping.html as Modbus slave, I wonder how many input registers the master can read with a single operation from ESP32.

Is it like the standard? So 256 bytes, and counting for headers/CRC, it reduces to 123 words for Modbus TCP

The theoretical limit for reading registers is 125, due to TCP overhead, it effectively limits the size of the data segment. The maximum number of words (16-bit registers) you can read in one operation is usually capped at 123 words