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4 Modbus TCP master
4.1 Working Principle
The Ethernet port supports Modbus TCP master functions, as follows:
Data exchange of Modbus TCP and PROFIBUS DP of EP-321MP is set up through “mapping”. There are
two data buffer areas, one is PROFIBUS DP network input buffer and the other is PROFIBUS DP network output
buffer. When the gateway acts as Modbus TCP master, Modbus read commands will write the read data to the
network input buffer for PROFIBUS DP accessing. Modbus write register commands get data from network
output buffer and export to the Modbus TCP slave equipment through write command.
Modbus TCP can support up to 36 Modbus TCP slave nodes and 128 commands, each command reads a set
of consecutive Modbus registers.
Modbus
device 3
Modbus
device 4
Modbus
device 5
Modbus
device 6
Input Buffer
Output Buffer
Summary of Contents for EP-321MP
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