GW-7553-B / GW-7553-M PROFIBUS/Modbus TCP Gateway User Manual
(Version 1.35, May/2017)
PAGE: 46
7553-B / GW-7553-M into the DP-Master, and then set the parameters. Finally
change your DP-Master from Offline state to Operate state. While DP-Master
changes to operate mode, GW-7553-B / GW-7553-M will initial the modules.
Then GW-7553-B / GW-7553-M allocates the memory space and waits for
Set_Prm telegram. The next step is waiting for Check_Cfg telegram in order. If
there is no error occurs, GW-7553-B / GW-7553-M proceeds into data exchange
state. Users can observe the status indicator LED to know the state of GW-7553-B
/ GW-7553-M. At the meantime, if there is any error occurs, GW-7553-B / GW-
7553-M will return to wait parameterization.
4.8 Data exchange example—Modbus RTU
In this example a Modbus master device simulated by a PC program sends query
message and receives response message from a Profibus master via the GW-7553-
B gateway.
In the following example the SIEMATIC S7-300 CPU313C-2 DP is used. The
configuration and communication is done by the program “Step 7 Manager”
provided by SIEMENS.
Step 1: Copy the GSD file and assign the GW-7553-B a valid station
address (Please refer to the section 4.2 GSD file).
Step 2: Connect the RS-232 port of the GW-7553-B module to a COM port
of the PC and the PROFIBUS port to a PROFIBUS Master (
Figure
34
).
Figure 34 Wiring diagram between PC and GW-7553-B
Step 3: Set GW-7553-B parameter “Modbus type” to slave and “Modbus
