profibus s7 em277

[ungaro]

Hi, I'm trying to link an S7-313c with a CP342-5 to an S7-224 with an EM-277 profibus module. When I try to compile the hardware configuration in Step7 I get the following message:The DP slave with the PROFIBUS address 4 of the
DP master system 181 has to contain at least one
module. In my hardware config I see that the EM277 is connected to the CP342-5. What does it mean and how do i solve it. I have no experience with profibus, just trying to learn on my own (and with a little help from you of course)
Thanks

 

[Kelkoon]

hardware

Dear Ungaro,

Can you post a project with your hardware configuration so we can try to compile it?

Kelkoon

 

[ungaro]

Thanks, hope you can tell me what i did wrong

 

[Kelkoon]

possible reason

Dear Ungaro,

I think I've found the problem. You have selected the EM 277 module, but you have not configured the module how many Bytes it should communicate.

If you click on the EM277. You can see in the botton of the screen "slot 0" and to the right blank. You should select a "communication module" to order master how many Bytes you want to communicate.

Kelkoon

 

[ungaro]

Yep, that's it, thanks a lot. OK. Now the compiling worked and I downloaded the configuration to the PLC. Now I want to communicate between the two. I read something about using FC1 and FC2 for sending/recieving. Any hints how to do it? (or can you post a simple example?). For example : if I switch on Input I0.0 on the S7-224 plc I want to switch on output Q0.0 on the CPU313c. What steps do I need? Thanks for your patience.

 

[Kelkoon]

Dear Ungaro,

When you communicate using EM277 as a PROFIBUS-DP slave, you communicate with data allocated on V memory. You can parametrize in wich Byte starts the interchange area (i.e. in the picuture, 2 Byte Inputs/ 2 Byte Outputs starting in VB1000).

VB1000 and VB1001 come from 315-2DP AB0 and AB1
VB1002 and VB1003 come from 315-2DP EB2 and EB3

Hope this helps you
Kelkoon

 

[ungaro]

Just managed to get communication between the two PLC's. It took a while but with your help and a bit of trying and searching it al worked out! learned a lot. Thanks for scharing your knowledge.