Restaurant POS without internet: what continues working during an outage?

Internet, local network and device connections are different

Losing internet does not necessarily disconnect a USB printer or the network between a register and a LAN printer. Losing the router, power or printer cable is a different failure. Ask which connection the demonstration actually removes.

Thermal receipts, kitchen tickets and fiscal receipts are also different documents. A locally connected printer proves only that a device path exists. It does not prove that a new unpaid order has been accepted, a print job has been created or a fiscal sale has been authorized.

What the current Rendo implementation supports

This guide distinguishes a new transaction during an outage from a print already in progress. The paired desktop caches its cashier page and menu. With a previously established staff session and active shift, new counter orders can be saved to a persistent local queue. That queue stores order drafts, not confirmed payments.

Table rounds and edits are excluded from this offline queue. New thermal jobs are obtained from the hosted order/print workflow and claimed centrally before printing. An already claimed job can reach the local printer and still need a later server acknowledgement; that is not the same as printing every new offline order.

A missing acknowledgement does not mean nothing printed

Rendo keeps a local print journal. If paper was produced but the server acknowledgement failed, recovery can reconcile the locally recorded result. An uncertain result needs physical inspection; printing again immediately can create a duplicate.

The same distinction matters for a fiscal device. Device communication may be local, but a new fiscal job, payment status and central acknowledgement are separate steps. Verify the exact device and accepted fiscal workflow on site. Do not treat a generic ‘offline POS’ label as fiscal approval.

What happens when the connection returns

The desktop submits queued counter orders using their saved operation identifiers and original location/shift context. An entry is removed after the server accepts it. Failed entries stay pending for review rather than being silently marked successful.

Inspect the queue before disconnecting or replacing a terminal. Reconnection may expose an expired session, changed catalogue, closed shift or revoked device that needs attention. A saved order is valuable, but it is not proof that payment, preparation and stock reconciliation are already complete.

Test the outage before opening night

Write the accepted behavior into your installation checklist. The code paths described here do not replace a test of the installed Windows terminal, printer drivers, local network and fiscal equipment.

1. Cache the paired desktop and establish the staff session and shift while online.
2. Disconnect the internet uplink while leaving the local printer/network powered.
3. Test a new counter order, table round, cash record, card terminal and each receipt separately.
4. Restart the application and check that pending counter orders are still present.
5. Reconnect, inspect accepted and failed entries, and compare payment and print results before retrying.