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EPOS Terminal Ports Explained: Serial, Powered USB, Cash Drawer and More

30 Oct 2026

Ports are the least glamorous part of an EPOS terminal, but get them wrong and you will spend your life with USB adapters and printers that randomly stop working. Here is what each EPOS terminal port does and why it matters.

Serial (COM / RS232 / RJ48 / RJ50)

Serial ports are still widely used for receipt printers, kitchen printers, scales, pole displays and some card machines. Many EPOS terminals present them as RJ48 or RJ50 sockets to save space. Having three built in, as on the HiStone HK568, HK566Q and HK788, means no USB-to-serial converters to fail.

Powered USB (24V)

A 24V powered USB port supplies both data and power to a compatible receipt printer or scanner from a single cable – fewer power bricks under the counter. The HK568 and HK788 each include a 24V powered USB port.

Standard USB 2.0 and USB 3.0

For scanners, keyboards, MSR readers and USB printers. USB 3.0 is faster for storage and some cameras. The HK788 has seven USB ports (two USB 3.0), and the HK566Q has seven (two USB 3.0) plus USB-C.

RJ11 / RJ12 cash drawer port

A dedicated 24V cash drawer port lets the terminal open the drawer directly, rather than through the printer. Look for it on every counter terminal.

LAN (Gigabit Ethernet)

Wired networking is the most reliable way to connect tills, kitchen printers and back office. Gigabit LAN is standard on HiStone all-in-ones.

HDMI and 12V display output

Used to drive a customer display or second screen. A 12V output powers the second display directly from the terminal.

24V power out

Some terminals, such as the HK566Q, can power a receipt printer from a 24V output – again, fewer power supplies.

Mobile EPOS: let the dock do the work

Tablets cannot carry a full set of ports, so the dock provides them. The HiStone HM628N smart dock adds three USB, two RS232 serial ports, Ethernet and a 24V cash drawer port, and the HM638N smart dock adds PoweredUSB 24V, two serial ports, LAN and a cash drawer port.

Port checklist before you buy

  • How many serial devices do you have?
  • Does your printer support powered USB?
  • Is there a dedicated cash drawer port?
  • Do you need a customer display output?
  • Wired LAN available at the till?

Talk to B-Spoke Systems about HiStone EPOS terminals

B-Spoke Systems supplies the full HiStone EPOS range in the UK from our Leicester base, for EPOS resellers, software houses and businesses alike. You can build and price a HiStone EPOS terminal in our configurator, book a visit to our Leicester showroom to try the hardware with your own software, or call 0116 260 3100 / email sales@b-spokesystems.com.