Give the printer a fixed address on the same network
Symptom: the scan finds nothing over Wi-Fi, or a printer that worked for weeks suddenly times out on every receipt.
Why it happens
Three network conditions cause almost all of it:
- Different networks. The till is on one Wi-Fi and the printer on another — a guest SSID, a second access point, or a separate VLAN. Printer discovery does not cross between them.
- Client isolation. Guest and public Wi-Fi usually blocks devices from talking to each other at all. The printer is on the same network and still unreachable.
- The address changed. Your router hands out addresses on a lease. When the lease changes, the printer moves to a new address while the saved printer still points at the old one — so it worked yesterday and times out today.
Do this
- Put the till and the printer on the same Wi-Fi, not the guest network.
- Print the printer's status sheet to read its current address. On an Epson, open the roll cover and hold Feed for a second; on a Star, hold Feed for five seconds while it's switched on.
- Give it a fixed address: reserve one for the printer's MAC address in your router's DHCP settings, or set a static address in the printer's own web page at
http://printer-ip. Either way it stops moving. - In the app, use Enter an IP address and type it in. That stops the scan and checks the one address directly, which works even when discovery is blocked.
If the address is right and it still times out, the printer may be holding a job — see printed once and then stopped.
Still stuck?
Use Copy setup report on the trouble screen and paste it into your message — it lists the address tried and which ports answered.