7
vacon • 74
Modbus TCP / Modbus UDP
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Figure 35. Modbus TCP and UDP communication errors comparison
11717_uk
Modbus TCP Communication
PLC
Drive
Modbus Query (1)
Modbus Query (2)
Modbus Response (1), TCP, ACK
Modbus Response (2), TCP, ACK
TCP, ACK
TCP retransmission, Modbus Query (2)
TCP retransmission, Modbus Query (2)
Normal communication continues
Packet lost, no response
Packet lost, no response
Modbus Query (1)
Modbus Response (1)
Modbus Response (4)
Modbus Query (2)
Modbus Query (3)
Modbus Query (4)
Packet lost, no response
Packet lost, no response
Normal communication continues
Modbus UDP Communication
PLC
Drive
Summary of Contents for optea
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