Every make of thermal printer answers the same commands slightly differently. Three taps on the printer's row settle the ones that vary, without anyone changing the app:
80 mm · 42 cols ⇄ 58 mm · 32 colsThe paper. A narrow head wraps at 32 characters; the wrong setting prints off the edge or leaves a third of the paper blank.
Feed + cut → Full cut → Partial cut → No cutHow the paper parts. Print a test after each tap and look at where it tore. No cut feeds three lines so the tail clears the tear bar.
Big text: standard ⇄ Big text: swapped bitsItem names on a ticket print tall. If they come out wide and run off the paper instead, the head reads the size byte the other way round: tap once.
Drawer pin 2 ⇄ Drawer pin 5Which pin the drawer's cable is on. Take a cash payment; if the drawer stays shut, tap once and try again.
The settings live with the printer on this terminal, and the dashboard can push them to a till from the device hub.
Related: Add a printer and test it · Settings pushed from the dashboard