SAP WPER — POS Interface Monitor
The POS interface is the two-way link between SAP and the tills. Outbound, SAP sends stores what they need to trade: article master data and prices. Inbound, stores send back what happened: sales totals, individual receipts, cash movements.
Both directions travel as IDocs, and both can fail. WPER is the monitor that shows the state of that traffic per store and per day, so you can see which store stopped talking and when.
The mental model that makes retail support tractable: outbound problems mean stores have wrong data (wrong price on the shelf, article that will not scan). Inbound problems mean head office has wrong numbers (sales missing from reporting, stock not depleting). Which direction has failed tells you who is affected and how urgently.
When you would actually use WPER
- A store reports a wrong shelf price and VKP2 shows the correct price in SAP.
- Sales figures for one store are missing from reporting.
- A new article will not scan at the till.
- Daily housekeeping: confirming every store transmitted overnight.
What the screen looks like
Selection
| Site | Date | Direction | Message | IDocs | Errors | Status |
|---|---|---|---|---|---|---|
| ST01 | 02.08.2026 | Inbound | WPUUMS | 1 | 0 | OK |
| ST01 | 03.08.2026 | Inbound | WPUUMS | 0 | 0 | Not received |
| ST02 | 03.08.2026 | Inbound | WPUUMS | 1 | 0 | OK |
| ST01 | 03.08.2026 | Outbound | WP_PLU | 1 | 1 | Error |
The fields, in plain English
The store to monitor. Blank checks every site, which is what you want for a morning sweep.
Outbound is SAP to store (articles, prices). Inbound is store to SAP (sales, receipts, cash). The direction tells you whether the shop or head office is seeing wrong data.
Which POS message. Inbound sales upload messages carry the day's trading; outbound messages carry article and price files to the till.
Watch out: Missing inbound sales are more urgent than they look — stock does not deplete and reporting understates, so the error compounds daily until fixed.
The distinction that catches people out. An ERROR means something arrived and failed. NOT RECEIVED means nothing arrived at all — usually connectivity or a till that did not run its end-of-day.
Watch out: A monitor filtered to "errors only" will not show a store that sent nothing. Check for absence as well as failure.
Step by step
- 1Leave the site blank and set yesterday and today as the date range.
- 2Execute and scan for both errors and "not received" entries.
- 3For an error, drill into the IDoc to read its status records.
- 4For "not received", the problem is at the store or on the connection, not in SAP.
- 5Fix the underlying cause, then reprocess the IDocs with BD87 or WLF_IDOC.
- 6Re-run WPER to confirm the store is clean.
Errors you will hit, and what they mean
Store shows "not received" for today
Why: The till never transmitted — end-of-day not run, network down, or the store is closed.
Fix: Nothing in SAP will fix this. Confirm with the store whether they traded and whether end-of-day ran.
Inbound sales IDoc in error
Why: Typically an article on the receipt that SAP does not recognise at that site — often an article sold before its listing took effect.
Fix: Check listing in MM43 for that article and site, correct it, then reprocess. The sale happened; the data just has nowhere to post.
Outbound price file failed
Why: Connectivity, or a condition record the store cannot interpret.
Fix: Confirm the price is right in VKP2 first, then reprocess the outbound IDoc. Until it succeeds the shelf price stays wrong.
Common questions
A price is wrong in the shop but right in SAP. Where do I look?
Here, outbound, for that store. The condition is correct but the price file has not reached the till.
Why are one store's sales missing from reporting?
Inbound sales upload either failed or was never received. WPER distinguishes the two, and that distinction decides whether you fix SAP or phone the store.
How is WPER different from WE02?
WE02 shows all IDocs generically. WPER frames the same traffic in POS terms — by store, by day, by direction — and shows absence as well as failure, which a generic IDoc list cannot.
Transactions that go with WPER
Reading about it only gets you so far
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