Modbus TCP/IP Communication Master and more than 2 slave devices

[Alican Tarım]

Good afternoon,

I have a V1040 Master Plc and I want to communicate more than 2 slave devices (v700,v570,v430 etc.)

I tried Modbus TCP-IP Master-Slave and UDP Master-Slave examples, but I could not communicate at the same time. While doing a sample with UDP, when I send data from Slave1, it writes to the Master MI20. Likewise, when I send data from Slave2, it writes to the MASTER MI20.

When I send data from Slave1 that I want, it will write to Master MI20. If I send data from Slave2, It will write to Master MI30

For example,

I want to write between MI100 and MI130, between ML100 and ML120 from Master PLC to Slave1 PLC.

I want to write between MI200 and MI230, between ML200 and ML220 from Master PLC to Slave2 PLC.

And also,

I want to read between MI500 and MI530, between ML500 and ML520 from Slave1 PLC to Master PLC.

I want to read betweeen MI500 and MI530, between ML500 and ML520 from Slave2 PLC to Master PLC.

 

I would be very happy, If you could help. If you want, I can send the application by e-mail.

Have a nice day.

 

[Flex727]

If you wish to communicate with 1 Master and 3 or fewer Slaves, MODBUS TCP should work fine. Just be sure your communication function blocks are properly set up and all IP addresses are unique and on the same subnet. There are example projects that came with your VisiLogic installation that show you how.

If you can't get MODBUS TCP working to your satisfaction, post your program here and someone will help you.