Hello All,

For Modbus TCP communication all CP 343 models can be used? In ST80 Customized Automation>> S7 TCPMODBUS   >> section it says CP 343 can be used.

Which among is best. CP343-1 lean can connect 8 slaves/CP 343-1 can connect 16 slaves. 

Dear guys

  i am facing promblem in s7 315 -2dp plc TCP modbus communication . i have cp 343-1 communication process  

please tell how to programm for tcp modbus communication and tell how to upload and download via cp343-1

i guys 

  please tell how to programm for modbus TCP via 343-1 .i need  to send data for other system

 which block need use for example i have 343-1 cp i want to take standard block from in cp343-1

 which block to be select

Hello saravanan;

This manual should have all the information and instructions required to connect your CPU to Modbus/TCP using a CP 343-1.

SIMATIC Modbus/TCP communication using CP 343-1 and CP 443-1

https://support.industry.siemens.com/cs/ww/en/view/103447617

The attached screenshot shows the required license (yes, this is not a free download) and the FBs that are used to program the exchanges.

Note that there is a free demo software available, but your PLC will run with diagnostic LEDs until the license is properly installed. For test purposes it is sufficient, see the following FAQ:

How do you establish OPEN MODBUS / TCP communication from a SIMATIC S7 and where can you find further information?

https://support.industry.siemens.com/cs/ww/en/view/22660304

Hope this helps,

Daniel Chartier