Hey,

On the Master side i have a S7-400 PLC and the Communication Port CP441-2 with installed Master RTU protocol and RS485 Interface Module.
On the slave side i have power circuit breaker from Schneider (Comapct NSX) combined with a Modbus Communication Interface Module (5Pins). I want to connect the CP 441-2 and the Interface Module with Modbus using RS485 (to connect more than one slave), but it doesn't work. Do you have any hints and tipps for me?

I configured the network with the default parameters (of the slave) on Master side (Baudrate, parity, stopbits...) and configured a PTP-Net as well. I am using the BSEND and BRCV blocks from Siemens to communicate, but it doesn't work.

How is the wiring of the modules, especially the ground wire (maybe anyone already made experiences)?

How important is the resistor at the last slave and what size should it have?

Is BSEND and BRCV correct or should i use any other blocks?

Is this connection even possible or does Schneider only communicate with Modbus TCP and i need some more Hardware here....?

Or maybe any other faults i could have made, i already read many instructions in the internet, but still can't make it working.

I am thankful for any good hint

 

Hi!

Do you have some solution on your problem. I see we have the same HW and the same problem, so what is wrong? did you found it?
Please write to [email protected] if you can share some experience.

Thank you!

 

Hi,

i have the same problem but with an other MODBUS slave.
Does one of you have a solution?

Thanks