S7-300 <-> S7-200

Hello everyone,

Sorry to be bothering you with what might be an easy question but I've been trying to put a S7-300 communicating with a S7-200 over profibus DP. I followed the hardware configuration sample at siemens (although i didnt quite figure out where to define the send and receive areas on the s7-300 like I'm supposed to) but now I need some kind of sample code to test this. I've just read about uni and bi-directional connections and also a bit about X_Get, X_Put, SFB14, SFB15. I've tried using them but no success on my part. I've also tried using PQW instruction like the one you can use to communicate with MM4 but that didnt work either. Now I'm just trying to send a byte or a bit (anything really) over to the S7-200 and access it.

I hope one of you might point me in the right direction.
Best regards,
Nuno

hello allstar;
Sorry I missed your post; have you made any progress since then?
If you follow the sample from Siemens point per point you should have data exchanges easily. Most problems with that type of setup come from mismatches in the data exchange tables in the various PLCs.
In this example, you want to exchange 2 bytes OUT (from master to slave), between the S7-300's QB10 and QB11 and the S7-200's VB100; and 2 bytes IN (from the slave to the master) from the S7-200's VB102 and the S7-300's IW10 (IB10 and IB11).

The S7-300 output/input areas are selected through the hardware Config Editor, when you specify the slave properties on the bus. The S7-200 VB areas are selected through the I/O offset in VB memory parameter of the EM277 (as per the Siemens sample).

Once both output and input areas have been properly mapped, whatever you write to the S7-300's QW10 (QB10 and QB11) will be transfered to the S7-200's VB100. And everything you write to VB102 in the S7-200 should be read in the S7-300's IW10.
As you are exchanging only 2 bytes both waysm, considerations of consistency (and SFB14 and 15 are not required at this point0, simply MOVE instructions.

If you cannot use the sample address areas for any reason, simply remap them in the configurations of both CPUs.
Also, can you give us a screenshot of your HWConfig for the S7-300 master, maybe we can have a look at it.

Hope this helps,
Daniel Chartier

Hi Daniel,

Thanks for the reply. The problem is that I have the S7-300 as a master in my network, so I can't specify the slave properties on the bus (since it doesnt allow me to add anything under the "configuration" tab on the DP properties). Already tryed to specify these while on slave mode but as soon as I revert it to master it loses what I added there. Am i trying to set these areas in the wrong interface?
I attached a screenie of the HW config as suggested.

Best regards,
Nuno

Hello allstar;Thanks for the screenie; unfortunately, you missed one step for me to be able to help:
Go back to the same screen you copied in your last post, click on the EM277 slave and in the bottom part of the screen you will see the I/O address selection for that slave (the areas of CPU memory reserved for the data on that slave). This is where you specify the QBxx and IBxx addresses for your data transfer.
Come back to us with another screenshot if you need more help.
Boa sorte,
Daniel

Hi Daniel,

I apologize for the late reply but I got so into this that I forgot to post a reply. Thanks for the tips, it's working properly now.

Kind regards,

Nuno

Hello Nuno;

Glad to have been of help.
Later,
Daniel Chartier