eModbus / eModbus

Modbus library for RTU, ASCII and TCP protocols. Primarily developed on and for ESP32 MCUs.

Home Page:https://emodbus.github.io

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7Data bit in RTU communication

MahdiBabaie opened this issue · comments

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is it possible to communicate with other plcs or devices using RTU protocol and using & data bit. in your RTU example, only 8 data bit have been used. when i try to communicate with my plc using 7 data bit it get me timeout error.

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You need to maintain the 7 bits in your application I am afraid, as Modbus generally is expecting 8 bit bytes. Server adresses may go up to 247, length bytes to 253 and error codes are 128 to 255, so there is no way for 7 bits at all.