User Manual
PROFIBUS DP Modbus TCP
/
Gateway
GT200-DP-MT
WWW.SSTCOMM.COM
11
4 Working Principle of Modbus TCP Master
Ethernet supports Modbus TCP master function, described as below:
Data exchange of Modbus TCP and PROFIBUS DP of GT200-DP-MT 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 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
