Your kitchen screen and your till should be the same app
Two screens polling separately can disagree — that is the day a ticket goes missing. Why the pass belongs in the ordering app, and when a dedicated screen wins.
The standard setup is a till on the counter and a kitchen display on the pass, talking to the same server and drawing their own screens. It works. It also has a failure mode that only shows up when you are busy.
Two clients, two truths
Each screen polls independently. Each has its own network connection, its own cache, its own idea of what happened in the last ten seconds. Most of the time they agree because they are asking the same server the same question.
When one of them loses signal for ninety seconds, they stop agreeing. The till takes an order the pass has not seen. Somebody bumps a ticket on the pass that the till still shows as open. If either screen ever holds work locally — and any screen that survives a network cut must — you now have two devices with different opinions about the same order, and a merge to do.
Add offline ordering to the picture and it gets worse, because the thing that went offline is now also creating orders rather than only reading them.
One app, one board
The simplest fix is not better syncing. It is fewer things to sync. If the pass is a screen inside the same app that takes the money, there is one client, one poll, one set of rows in memory. The board on the pass and the board behind the till are literally the same data structure. They cannot disagree, because there is nothing to disagree with.
It also solves a smaller problem that matters commercially: a stall with one tablet. A single-counter trader at a market does not want to buy a second screen to find out what to cook. They want to take the money and work the pass on the device they already have.
When a dedicated screen still wins
This is not an argument against kitchen displays. A busy kitchen wants a big screen on the wall showing everything, readable from across the room, that nobody is touching to take payments on. That should absolutely stay available.
The point is that it should be the same board seen on another device, not a different product with its own sync story. Both should be reading one source, and a venue should be able to run either, or both, without choosing between them at purchase time.
What a kitchen board has to get right regardless
Three rules we hold to on ours, all of them learned the hard way:
- Never miss a ticket. Pull the whole open set and reconcile it rather than replacing the screen with whatever arrived. A failed poll must leave the screen exactly as it was, because a blank board looks identical to no orders.
- Never shuffle. Cards hold their position. A board that reorders itself under somebody's hand gets the wrong ticket bumped.
- Never lie to a customer. Colour should run against what the guest was told, not against the clock. Forty minutes is fine if they were quoted an hour. Ten is a problem if they were quoted five.
HelchPOS runs the kitchen board inside the till app and as a standalone screen, off the same data. If you are weighing up a second screen per counter, that is the question worth asking your supplier: is your kitchen display the same board, or a different program that has to agree with the first one?