point_of_sale_test_epos

Epson ePOS printers are configured in Odoo with nothing but an IP address, and until Odoo 19 the only way to know whether that address worked was to open a session and try to print a receipt. This widget is the shortcut: a Test button that talks to the printer directly from the settings form.

What the click does, verified in the source: it builds a minimal ePOS-Print XML envelope, one centered line reading This is a test receipt, three line feeds and a cut, and POSTs it to /cgi-bin/epos/service.cgi?devid=local_printer on the configured IP with a 15 second abort timer. It then parses the SOAP response: on success you get a confirmation toast, and on failure the Epson error code is looked up in a table of nine known conditions and shown as a readable warning.

The widget renders a plain secondary button and stores nothing. It is registered in the view widgets registry, so it appears in XML as a <widget> element, and core places it in three spots: the POS settings page, the POS config form and the printer form, where it hides unless the printer type is epson_epos.

Receipt printers fail at the worst possible moment: during opening hour with a queue at the till. Every minute a cashier spends wondering whether the problem is the network, the printer or Odoo is a minute of lost sales. This button collapses that triage to one click made before the shop opens.

The error mapping is the real value. Printer cover is open, The paper is empty, Check the Device ID setting, it should be local_printer: each of these turns a support ticket into a ten second fix by the person standing next to the printer. For multi-site retailers, having store managers run the test after any router or printer change keeps the helpdesk out of the loop entirely.

On the printer form, gated by printer type

<widget name="point_of_sale_test_epos"
        invisible="printer_type != 'epson_epos'"/>

Verbatim from the core printer form: the button only appears for ePOS printers, not IoT ones.

Next to the settings field

<field name="pos_epson_printer_ip"/>
<widget name="point_of_sale_test_epos"/>

The settings page pattern: the widget picks up pos_epson_printer_ip from the record because the field sits in the same view.

The protocol selection is where real deployments stumble, and the source is explicit about it. When Local Network Access is off, the request uses window.location.protocol: an Odoo database served over HTTPS will therefore call the printer over HTTPS too. Consumer ePOS printers do not ship trusted certificates, so the browser blocks the request and you land in the catch-all message about checking the URL and the network, even though the IP is perfectly right. That is exactly the scenario Epson's self-signed certificate procedure, or Odoo's LNA mode, exists to solve.

With LNA enabled, the widget takes the other branch: at load it asks the server's pos.printer.use_local_network_access, and on click it forces plain http:, attaches the browser's target address space hint and walks the LNA permission flow before sending anything. A denied permission aborts the test cleanly rather than reporting a printer fault.

One more hardcoded contract: the query string pins devid=local_printer. If the printer's internal Device ID setting differs, Epson answers DeviceNotFound, and the widget's mapped message tells you precisely which setting to fix. The nine mapped codes also include the drier hardware ones: cutter jam, mechanical error, low voltage, bad port and a plain timeout.

Odoo 20 is expected at Odoo Experience in Brussels, 24 to 26 September 2026. We read this widget's file on the public development branch at the time of writing; the branch is unstable and details can change before release.

The development branch rewrites the widget substantially: it fetches printer settings per printer via orm.read (printer_ip, printer_type, use_lna, paper_size), on the POS config form it iterates and tests all configured printers in one click, label printers with paper_size set to label get a raw ZPL test sent to /pstprnt instead of the ePOS SOAP call, the receipt text now includes the printer's name, and notifications are prefixed with the printer name and IP. Two long-standing typos in the error table (occured) are also fixed. We re-verify after release.