How to find PIW / PQW in S7?

uptown47

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Feb 2008
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Hi all,

I recently was trying to find the addresses being used by a DP/DP Coupler in S7. The addressing was Input Word 20 and Output Word 20.

The Cross Reference data didn't show any bits being used at all as though these words weren't being addressed but then I found them (quite by chance) in the software addressed as peripheral words (i.e. PIW20 and PQW20).

The programmer was 'moving' them into Marker Words for manipulation in the software.

My question is, how do I check if an address is being used as a Peripheral Word ? Is it possible ? It doesn't show up on the normal reference data so is there another way to check apart from using 'Go To Location' for every address which you suspect is peripheral.

Many thanks

;-)
 
Since the PIW and PQW words have been used in the program, they should appear in the cross reference.
Check that the filter in the cross reference includes peripherial adresses.
There is a small possibility that the cross reference has become defective. Delete it and generate it again.

Apart from that, for a DP/DP coupler, it would be most typical that the access is via SFC14 and SFC15. Manipulating PIWs and PQWs means there is a risk the data in one PIW address isn't syncronised with the data in another address. SFC14 and SFC15 ensures the data is consistent.
 
Hi Jesper,
You are right, they are showing up in the Cross Reference. They weren't selected (although it was showing 'no filter'). However, they still don't show up in the "Assignment" table (within the Reference Data). Should they show up in there?

Many thanks

;-)
 

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