Hello,

I am new to using profibus communication so please bear with me.

I have gone through the forums, but I may have missed something related to this.

I am trying to read analog data into my Siemens from the Peripheral Input of another Siemens Plc through a DP coupler.

Is this possible to do directly?

Do I have to alter (prepare a data write and add dp coupler in its hardware Configuration) the project of the already existing PLC in order to read the data I need?

Please help.

...sent from App

Hello,

I recommend check documentation (link): DP/DP Coupler manual

nixander

Do I have to alter (prepare a data write and add dp coupler in its hardware Configuration) the project of the already existing PLC in order to read the data I need?

Yes. The target PLC must write the data you want to read to the coupler. So, it must know that the coupler is out there, i.e. it must be added to its hardware configuration.

Duris_I

Hello,

I recommend check documentation (link): DP/DP Coupler manual

 Hi Duris,

thanks for the suggestion. I actually read that manual before posting my question. I didnt find it very helpful during the programming stage due to its lack of application examples.

jacek d

Yes. The target PLC must write the data you want to read to the coupler. So, it must know that the coupler is out there, i.e. it must be added to its hardware configuration.

Thanks alot for your response. This clarified a lot of things. Its now starting to make sense. 

One last question,

So assuming i want to read an analog device with address PIWXXX, on the partner PLC, do I write the to an output word address configured in the hardware config, and read the input word address on my PLC? 

Is there a better/more standard way to implement it?

Hello nixander,

problem is your not clear info about your requirements, situation. You've mentioned DP Coupler use but still missing clear info what is your CPU with Profibus set (Master/Slave). This is also important to know because then maybe other options are avialble. In other case keep in mind that if all documentations need have any kind of required examples as users need to look, I don't imagine how that documentations need looks like...

Update: so better question is why you need use that Coupler...

Duris_I

Hello nixander,

problem is your not clear info about your requirements, situation. You've mentioned DP Coupler use but still missing clear info what is your CPU with Profibus set (Master/Slave). This is also important to know because then maybe other options are avialble. In other case keep in mind that if all documentations need have any kind of required examples as users need to look, I don't imagine how that documentations need looks like...

Update: so better question is why you need use that Coupler...

 Well, I want my PLC to communicate read/write data to a partner PLC that is on another Profibus network. That partner PLC is already existing. I need to read the analog level of a transmitter on the partner PLC. 

Hi nixander, 

Just to attach with a sample configuration i done in my project. 

The output i set in CPU410-5H is the input of the vendor set at S7-1200. The configuration must be the same in order to establish the communication. 

Hope it helps.