S4M Serial Communications Information

Article ID: 77015027



Communicating to printer via serial port connection

This solution is useful for:

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


Symptoms resolved by this solution include: 

  • Data light does not flash when print job is sent
  • Data light flashes but does not print
  • Printing garbage, skips print, and random misprints
  • Printing slow, may have long pauses between prints

Applies To

S4M printer communicating via the RS232 Serial Interface


Serial communications requires that all data settings are matched between the host and the printer.

A NULL Modem Cable must be used between a PC and the printer DB9 interface. Read More>>

Pin out for a 9 pin host to 9 pin printer cable Read More>>

Pin out for a 25 pin host to 9 pin printer cable Read More>>


An RS232 communications interface is included with the printer and allows for serial communications between the host and printer. All parameters must match to work properly including the Host Handshake setting. 

Review the printer communications settings in the ZPL printer menu Read More>>


1. Connect the Serial Cable to the printer and host (connection to a PC Com port requires a NULL MODEM)

2. Create a test file label format using the programming language your printer supports (V58 is ZPL, E50 is EPL)

3. Send the file to the printer using a send function of your application or utility.

The printer should respond to the test format.

If the printer does not respond

  • Verify the data is getting to the printer
  • You are sending a complete label format using the compatible printer language
  • Verify the Host and Printer are configured for the same Baud, Data Bits, Stop Bits, and Parity. Print a configuration label to check the printer settings Read More>>

Helpful Information

Sending a file to the printer using the Zebra Setup Utility Read More>>


+ Product Codes

  • S4M
  • S4M Series