A
CASE 1
Environment: In the MODICON PLC device, there are Modbus+ module, Remote I/O module and Modbus TCP module. The Modbus+ module connected to user Modbus+ network, the Remote I/O module connected to user I/O, and the Modbus TCP module connected to user Ethernet.
Description: We connected to MODICON PLC device with IP Address (128.1.30.32) and sent out a request with writing a value 5 into register 400020¡C
Format of WriteMultipleRegister Packet as following:
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
01 01 00 00 00 09 00 16 00 19 00 01 02 00 05
AP received a reply as following:
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12
01 01 00 00 00 06 00 16 00 19 00 01
Result: After WriteMultipleRegister request, we received a normal reply. Then, we used the web utility to watch the register 400020, but there is nothing change.
CASE 2
Environment: In the MODICON PLC device, there are Modbus+ module, Remote I/O module and Modbus TCP module. The Modbus+ module didn¡¦t connect to user Modbus+ network, the Remote I/O module didn¡¦t connect to user I/O, and the Modbus TCP module connected to user Ethernet.
Description: We connected to MODICON PLC device with IP Address (128.1.30.32) and sent out a request with writing a value 5 into register 400020¡C
Packet: Format of WriteMultipleRegister Packet :
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
01 01 00 00 00 09 00 16 00 13 00 01 02 00 05
We received a reply as following:
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12
01 01 00 00 00 06 00 16 00 19 00 01
Result: After WriteMultipleRegister request, We received a normal reply. Then we used the web utility to watch the register 400020. The value of the register 400020 was 5.
Could someone tell me what happen?
Environment: In the MODICON PLC device, there are Modbus+ module, Remote I/O module and Modbus TCP module. The Modbus+ module connected to user Modbus+ network, the Remote I/O module connected to user I/O, and the Modbus TCP module connected to user Ethernet.
Description: We connected to MODICON PLC device with IP Address (128.1.30.32) and sent out a request with writing a value 5 into register 400020¡C
Format of WriteMultipleRegister Packet as following:
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
01 01 00 00 00 09 00 16 00 19 00 01 02 00 05
AP received a reply as following:
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12
01 01 00 00 00 06 00 16 00 19 00 01
Result: After WriteMultipleRegister request, we received a normal reply. Then, we used the web utility to watch the register 400020, but there is nothing change.
CASE 2
Environment: In the MODICON PLC device, there are Modbus+ module, Remote I/O module and Modbus TCP module. The Modbus+ module didn¡¦t connect to user Modbus+ network, the Remote I/O module didn¡¦t connect to user I/O, and the Modbus TCP module connected to user Ethernet.
Description: We connected to MODICON PLC device with IP Address (128.1.30.32) and sent out a request with writing a value 5 into register 400020¡C
Packet: Format of WriteMultipleRegister Packet :
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
01 01 00 00 00 09 00 16 00 13 00 01 02 00 05
We received a reply as following:
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12
01 01 00 00 00 06 00 16 00 19 00 01
Result: After WriteMultipleRegister request, We received a normal reply. Then we used the web utility to watch the register 400020. The value of the register 400020 was 5.
Could someone tell me what happen?
