A
Dear Sirs:
I have a PLC (master) and a temperature controler (slave) that are communicating via modbus rtu.
I have to send to the slave the bytes 1 4 0 0 0 8 CRC CRC (function 4 of modbus to adress 1).
After i ask the first question 01 04 00 00 00 08 CRC CRC (function 4 of modbus), the module answer is OK. (01 04*****************************)
But when i send this command again, the slave returns 132 1 130 1 192 1 and remains cycling these bytes. This make no sense for me.
Why does the slave send to me the right response only in the first time that I ask?
Sorry for my terrible english.
Regards,
André Lakatos
Eletro-Forming
Rua Cesária Camargo de Oliveira, 280
Embu-SP
Tel : (0xx11)4704-3699
Fax: (0xx11)4704-3987
[email protected]
www.eletro-forming.com.br
I have a PLC (master) and a temperature controler (slave) that are communicating via modbus rtu.
I have to send to the slave the bytes 1 4 0 0 0 8 CRC CRC (function 4 of modbus to adress 1).
After i ask the first question 01 04 00 00 00 08 CRC CRC (function 4 of modbus), the module answer is OK. (01 04*****************************)
But when i send this command again, the slave returns 132 1 130 1 192 1 and remains cycling these bytes. This make no sense for me.
Why does the slave send to me the right response only in the first time that I ask?
Sorry for my terrible english.
Regards,
André Lakatos
Eletro-Forming
Rua Cesária Camargo de Oliveira, 280
Embu-SP
Tel : (0xx11)4704-3699
Fax: (0xx11)4704-3987
[email protected]
www.eletro-forming.com.br