General Modbus is generally big-endian based. The only exceptions are the commands with function codes 43 (2Bh), 101 (65h) and 102 (66h), which are based on CANopen. For the data values of these commands, the little-endian format applies. The remainder of the Modbus message is, on the other hand, based on big-endian. Example Command 2Bh: With this command, the value 12345678h is written in object 0123h (does not exist): SA Slave address FC Function code Data Data range, decoding is dependent on the used function code CRC Cyclic redundancy check Note: In case of more than one Modbus slaves in the network, the Modbus master must wait for at least 3 ms after receiving a response before sending the next request. Tip: To send a broadcast message to all nodes, use slave address "0". The controller does not respond in this case.
General Modbus is generally big-endian based. The only exceptions are the commands with function codes 43 (2Bh), 101 (65h) and 102 (66h), which are based on CANopen. For the data values of these commands, the little-endian format applies. The remainder of the Modbus message is, on the other hand, based on big-endian. Example Command 2Bh: With this command, the value 12345678h is written in object 0123h (does not exist): SA Slave address FC Function code Data Data range, decoding is dependent on the used function code CRC Cyclic redundancy check Note: In case of more than one Modbus slaves in the network, the Modbus master must wait for at least 3 ms after receiving a response before sending the next request. Tip: To send a broadcast message to all nodes, use slave address "0". The controller does not respond in this case.
