28xx/38xx Series - Communicating to the printer via serial port

Article ID: 53943024


Important: If you are using an LP2844 printer that is used for or supplied by a shipping vendor (i.e. UPS or FedEx for example) DO NOT try to load standard firmware or drivers from the Zebra Website. These printers are used exclusively with the shipping vendor's driver and label application. Read More>>


Topic or Information

Communicating to printer via serial port communication

This solution is useful for:

  • Setting serial port parameters
  • Serial cabling and pin out requirements
  • Testing the serial port using DOS
  • Diagnosing data received by the printer

Applies To

LP/TLP2844 Printers 
TLP3842 Printers


Serial Communication requires that the proper RS232 cable be used and that the host and printer's serial communication settings are matched. That includes Baud Rate, Data Bits, Stop Bits, and Parity. Flow Control must be used as well to avoid buffer over runs.

  • Use a straight though cable when connecting the printer to a PC.
  • Assure you have the host and printer communications setting correctly matched
  • Make sure you are sending the printer's command language (EPL) from your host or label program. The printer will not respond if the EPL commands are not received or if not properly formatted.
  • If you send label requests and there are issues after a couple labels, make sure your flow control is set on the host


The printer default serial port settings are 9600 baud, 8 data bits, 1 stop bit, no parity.  For Flow Control both DTR and XON/XOFF are active all the time. (Hardware and Software flow control) Read More>>

The best way to confirm communication from the PC to the printer is in DOS. This method bypasses Windows software and drivers which may be disrupting communication. Read More>>

You can print a configuration label to determine or confirm the printer communication settings. Read More>>

To determine if the printer is getting data you can put the printer into dump mode. The EPL commands received by the printer will be printed when in dump mode. Read More>>


+ Product Codes

  • 2824 Series Desktop Printers