A4 Printers (System Printing)

Besides receipt and label printers, the bessa Kassa can also output invoices, reports and receipt copies on an ordinary A4 printer. There is no dedicated bessa printer driver for this: the Sales Point renders the print job as a PDF in A4 format and hands it over to Android system printing. Which printers are reachable that way is therefore decided by the device's Android print system, not by bessa.

Technical Requirements for the A4 Printer

Whether an A4 printer can be used depends solely on whether the Android print system finds it and can send jobs to it. The vendor lists for receipt printers and label printers are irrelevant here. The following requirements apply:

• A print service on the device
  Android only knows printers through an installed print service: the default print service included in Android (from Android 8 on), the Mopria Print Service, or a plug-in provided by the printer vendor. Without an active print service, the print dialog only offers output as a PDF file.

• Driverless printing (IPP)
  The printer must be addressable without a driver, meaning it speaks the Internet Printing Protocol (IPP) and accepts jobs as PDF, PWG Raster or PCLm. Data sheets usually list this as Mopria certified, IPP Everywhere or AirPrint. Devices that only accept classic driver formats (PCL 5, PostScript) on raw port 9100 are not discovered.

• Network connection
  The printer must be reachable over LAN or Wi-Fi. An A4 printer attached by USB or USB OTG cannot be addressed through system printing.

• Same subnet as the device
  Discovery runs over mDNS/Bonjour (UDP 5353), which is not forwarded between subnets. The device and the printer must sit in the same subnet, or the network must forward mDNS explicitly (mDNS reflector).

• Unrestricted communication on the local network
  The print job is transferred over IPP on TCP 631 (encrypted: IPPS). Client isolation, which is common in guest Wi-Fi networks, blocks any connection between the device and the printer.

• A fixed place on the network
  As for every device at the location: a static IP address or a reserved DHCP lease.

Assigning the Printer in the Sales Point

1. Open Menu → Settings → Devices & Connections → Printer assignment.

2. Tap the printer role you want — Invoice Printer and Report Printer are the meaningful ones.

3. Under Select printer vendor/driver, choose the entry PDF printer.

4. Choose the entry System printer from the printer list and save the assignment.

5. Configure the role's settings — such as template or number of copies — as usual. All details are documented under Printer Settings.

What Happens During Printing

When the Sales Point sends a job to the system printer, it renders the PDF first and hands it to Android. Android then places its print dialog on top of the Sales Point screen. There you pick the target — one of the discovered printers or output as a PDF file — and confirm the job. Only then does the print leave the device.

While the print dialog is open, the Sales Point does not log the current user out automatically. The job is therefore not lost if the dialog stays open for a moment.

Limits of System Printing

• No unattended printing. Every job needs the Android print dialog and a Sales Point running in the foreground. Order tickets, expediter tickets and automatically triggered printouts cannot be produced this way — those require a receipt printer.

• A4 layout instead of a receipt roll. The printout is laid out on an A4 page and uses the full page width. It therefore looks noticeably different from the same document on a receipt roll.

• No cash drawer, no buzzer. Both functions require a connected receipt printer and are not available through system printing.

• Fallback in Auto mode. If a printer role is set to Auto and the Sales Point finds neither a built-in printer nor a matching device on the network — and no main Sales Point steps in — it falls back to the system printer. An Android print dialog appearing unexpectedly is a sign of an incomplete printer assignment.

Frequently Asked Questions

Does the A4 printer have to be from a specific vendor?
No. Unlike receipt and label printers, system printing is not tied to vendor drivers. Only the technical requirements listed above matter.

Can I store invoices as PDF files without a printer?
Yes. Choose output as a PDF file in the Android print dialog; the file is then stored on the device.

Can I use an A4 printer and a receipt printer at the same time?
Yes. Assignments are made per printer role: the invoice printer can use the system printer while order tickets keep going to a receipt printer.

Can a sub-terminal print on the main Sales Point's system printer?
No. System printing always runs on the device that triggers the job and requires a confirmation in the print dialog there.

Troubleshooting

• The print dialog only offers output as a PDF file.
  No print service is active on the device, or the service has not found a printer. Check the Printing section in the Android settings to see whether a print service is enabled and whether the printer appears there.

• The printer does not show up in Android.
  Usually the printer sits in a different subnet, multicast (mDNS) is blocked on the network, or the Wi-Fi separates its clients. Check these three points together with your IT team — see Network security & port requirements. If the print service allows adding a printer by IP address, that bypasses mDNS discovery.

• Nothing happens when printing.
  System printing needs the Sales Point in the foreground. Trigger the print again without switching to another app in between.

• The printout looks small or misaligned.
  The layout targets A4 with fixed margins and cannot be adjusted in the Sales Point. Paper format and scaling can be changed in the Android print dialog.

Related Topics

• Printer Settings — connecting printers, assigning roles and printing groups

• Receipt Printers and Label Printers — supported vendors

• Network security & port requirements — ports and discovery on the local network

• Print an Invoice Copy