User Manual

2 Protocol description

Response in

the event of an

error

The function code is ORed with 0x80, which means that the MSB (most

significant bit) is set to 1.

Example Data request:

Response:

Special cases The slave will not respond in the following error situations:

- the checksum (CRC16) is not correct

- the instruction from the master is incomplete or over-defined

- the number of words or bits to be read is zero

Slave

address

Function

XX OR 80h

Error code Checksum

CRC16

1 byte 1 byte 1 byte 2 bytes

01 03 40 00 00 04 CRC16

01 83 02 CRC16