How many register a Modbus TCP master can read from ESP32

AndreaS73
Posts: 11
Joined: Tue Jan 16, 2024 8:16 am

How many register a Modbus TCP master can read from ESP32

Postby AndreaS73 » Mon Sep 09, 2024 3:03 pm

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

aliarifat794
Posts: 170
Joined: Sun Jun 23, 2024 6:18 pm

Re: How many register a Modbus TCP master can read from ESP32

Postby aliarifat794 » Mon Sep 09, 2024 3:36 pm

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

Who is online

Users browsing this forum: Gaston1980 and 125 guests