Hello everyone,

There's a test project a purpose of which is:

• reading 70 Bytes from coupler address to DB1;
• writing 70 Bytes from DB to coupler address;

• reading Byte 69 to DB2 and forwarding to a respective address of coupler.

Msorich

 Hello dchatrier

dchartier

Your program confuses me, and I have a feeling you are confusing the Step 7 compiler as well.

No, the poor compiler is OK.

dchartier

Are you trying to write from PLC1 to a DB in PLC2? And are you trying to read from a DB oin PLC2 to PLC1?

I'm trying to read 70 Bytes from Coupler into special DB1's part called 'Inputs'. At the same time I'm trying to take data from special DB1's part called 'Outputs' and send them (70 Bytes) to Coupler respective addresses.

dchartier

This would not work. Look at the hardware configuration of the DP/DP coupler, you will see that in each PLC,s hardware configuratio there are only I and Q addresses for the coupler. And you must use I and Q addresses in each PLC's configuration.

Well, luckily reading/writing is working (checked on the real hardware). I mean NW1, NW2. So I'm not concerned about this part of test project. Perhaps I need to concern about, though.

As I wrote  above I'm stuck on trying to figure out how to realize the second part of test project, in particular forwarding a Byte.

Msorich

 Hello dchartier

dchartier

What, if any, are the codes appearing in your RET_Val output (#dummy_rsv)?

 At the moment the both Ret_Val are not used and system doesn't allow to leave these outputs empty.

So I just created couple of dummy vars.

dchartier

At first glabnce the Srcblk and Destblck parameters do not match in size.  In Netw 3 your Srcblk is a pointer to a 1 byte register, whereas the Dstblk is a DB (DB2). You should try refining your DB address to le byte level to make sure the byte value is transferred to a specific location i your DB, eg DB2.DBBxxx.or "Buffer_DB".Recv_byte (for example).

Here also everything is OK, I think. You just was confused by symbolic addressing. Take a look at attachment.

That what bothers me it is simultaneous writing both SFC15(NW2) and SFC20(NW4) in the same range  of addresses. Whether simultaneous writing is going to be a source of data collission.

Msorich