RTU slave frame format

[ruchikdv]

What should be my RTU frame (IN HEX) if my slave id is 1
I want to send data of a sensor to my PLC through AVR if first byte of request is 0x01 (irrespective of the request function code)
Data size is 10 bytes
Data is: 0A 2D 30 30 30 32 34 2E 30 0D

[K C]

RTU frame. You mean a RTU ModBus slave ?? 

Beside the slave address you also need a ModBus address of the register for the data write.

The data you want to write is: <LF> -00024.0 <CR> Are you sure that is the data you must write in this format ??

[ruchikdv]

yes. I am looking for Modbus RTU slave frame. Yes the data is in the format you mentioned. I am not aware where should the register address be placed in the frame and whether I should add the count of Data bytes in the frame. I am even unsure whether data should be in 16bit or 8bit format.

[K C]

You also have to know what ModBus commands your slave supports.

Normally a ModBus  register is  16 bits.

Do you have a manual of your ModBus Slave ?

Kees

[ruchikdv]

I am writing the program for the Modbus slave and irrespective of the command I receive, I wish to send the Modbus frame with the data above.

[K C]

Do you have more information about your ModBus Slave. What commands does this slave support