5 MODBUS RTU Protocol communication
CP340/CP341/CP440/CP441 Communication and Programming
Entry-ID: 88867653, V1.0, 02/2014
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Fig. 71: Invoke FB80 from OB1
4. Create FC03,06,16 function code communication data block DB1.
Fig. 72: Communication data block DB1
5. Create FC04 function code communication data block DB2.
Fig. 73: Communication data block DB2
5.1.4
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.
5.1.5
Communication test
1. Download hardware configuration and program into CPU315-2DP firstly. Open
MODBUS master emulation software Modscan32 in the computer.