Hello Everyone,

I'm asking for your help. I'm working with project with CP-342-5 and CPU 315-2 DP and I want to establish connection beetwen CP-342-5 and Device  which isn't in my project by Profibus DP. I set CP-342-5 as DP slave and i want to use I-slave communciation, so I want to set Slave adres in Transfer areas but it is impossible. Do i make mistake or in CP-342-5 it isn't possible?

Hi Dominik,

FIRST: you need to establish the connection path.

IN your image: Asigned DP Mastes is empty!

NOTE: My TiaPortal is on spanish, maybe the texts you'll have are similar but not exact.

On Hardware, click on the red section of the image

Operation MODE: CONTROLADOR IO/PROFIBUS Asigned: XXXXX

Then, you could define the Comunication-I-device

There, you could create the exchange areas.

Thank for your replay

In this project I havn't master device. The network should be created but not connectet to other device. In similar project where i have only CPU I was able to assign adreses in transfer areas. Now I want to do the same w CP.

Hi Dominik,

In this case, I don't know how to assign the directions for a I-slave on PROFIBUS without a DP-master. 

Is not possible to put it on your project?¿

Hello,

hope I good remember, inside CP you need have set DP Slave functionality of CP. Then you need use DP_SEND and DP_RCV with defined I/O buffer, also some Slots need to be maybe inserted with specific length and data type of buffer (check that inside docs). Check pls Forum for Example CP-342-5, also with Step7 v5.x you can check example pdf how it need to be prepared.

Update: of course you don't need define any master if your CP is Slave.

Update2: eeeh forget that I-Slave can be set only with CPU internal DP port not with CP (hope good remember).

Thanks for your response. I've just read some manuals and you are right. 
But now I have another questions. In my CP transfer is limited to 240 byts. I know ther is posible to send more data by DP_SEND and DP_RECV. But in what way it will be transfered by CP?

For example i Need send 320 bytes, so I set transfer areas as in the picture. Is in the next step I should call 10 times DP_send ? Will it works properly? Should I make breaks beetwen calling next DP_SENd?

Hello,

eeeehm I don't know exactly heh. I see like this, your Master logically need have same consistency, better say it define that 'consistency' buffer and you as Slave need have same consistency, if we can say like that. Really I can't now imagine how it can be achieved because master also need have implemented something what I can't now imagine. I see that restriction of cca 240 Bytes as rule in this case, simple.

Update: eeeh you need execute that blocks cyclically (REQ->true for both f.ex.).

Hello,

so? Ok, check generally this documentation (but expect you already did):

SIMATIC CP342-5 Profibus manual