Thermal Barcode Printers: An Introduction to Interfaces

by ScanSource Technical Services on September 16, 2010 · 0 comments

in Barcode Printing,POS,RFID,ScanSource POS & Barcode,Technical Education Portal,Technology,Wireless

The interface is how the host that is generating the print job communicates with the printer. No one printer is going to support all of these possible interfaces so it can be important to know ahead of time how your customer intends to connect to the host so you can make sure the printer is going to have the appropriate interface installed. Let take a moment and look at each.


This is the traditional printer interface found on most PCs. In years past it was pretty much how all office/home printers connected. It was also common with Thermal Barcode printers. While it is not as popular now as in years past, it is still a common interface. Parallel’s major limitation was speed and the 10 foot max length of the cable. Since the parallel interface has been such a standard it is easy to find cables. Parallel was common in office settings where the printer could be near the PC. As USB becomes more popular, it is replacing parallel.

RS-232C Serial:

The standard RS232 serial port is a very generic interface that has been used to interface just about any type of peripheral imaginable, including printers. It is slower than parallel but has the advantage of using longer cables, up to 50 feet. In years past serial was common in industrial settings but as it becomes more common for printers to be network devices you see less and less serial.


USB is a general interface, similar to serial, that can be used for a wide range of peripheral devices, including Printers. While it is much faster than either serial or parallel, with a max cable length of 10 feet, it has some of the same limitations. As a printer interface it is commonly seen in office settings.


What has become the most common way of connecting Thermal Printers is ethernet. This makes the printer an actual device on the network, with its own IP address. Putting the printer on the network solves many of the limitations of other interfaces. Modern networks are significantly faster than serial/parallel, and with a max cable length of Cat 5 ethernet cable being 100 meters (328 feet) the printer is free to be placed where needed, not just where the host is. Being a network device, the printer is also available to any host on your network with the correct permissions.

Wireless Ethernet:

Taking it one step further, the printer can also be fitted with a wireless network interface. This allows the printer to be connected to an existing 802.11 wireless network. This is very useful for printers that would be used at different stations (rolling cart for example) or printers that need to be utilized at locations where running cables would prove impractical.

Legacy Interfaces:

There are a couple of interfaces that you still see from time to time. Both were used mainly in industrial settings. As networking technology developed, both have been phased out in favor of Ethernet.

RS-422/RS-485 Serial:

These were serial interface standards for connecting multiple devices over long distances. There are still a few high end printers that support them.


Used with early networking technologies. Twinax/Coax is still supported by some high end printers, and is still seen usually in an AS400 environment.

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