Siemens SIMATIC S7 CP340 Programming Manual page 68

5 MODBUS RTU Protocol communication
3. Invoke FB180 function block .
Fig. 122: Invoke FB180 function block
5.4.4 Equipment connection
Use standard RS232C cable to connect serial ports of CP341 and computer. The
detailed cable connecting method may be seen in CP341 Manual - Chapter B:
Connecting cables.
5.4.5 Communication test
Download the hardware configuration and program into CPU. Open the software
Modscan32 in the computer, and click Connection—〉Connect in Modscan32 to
display the following screen. Select the used serial port, and set Baud rate, data
bit, stop bit and check mode, and select a communication protocol according to the
applicable connection. After setting completes, click OK to display the monitor
screen.
CP340/CP341/CP440/CP441 Communication and Programming
Entry-ID: 88867653, V1.0, 02/2014
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