Z-Series RS232 Serial Communications Information

Article ID: 97528016




This document detail ZM Series serial communication and methods to troubleshoot problems.

Questions answered

  • How do I set up the printer for serial port communications?
  • What cable do I need to connect the printer via the serial port?
  • How can I see the data the printer is receiving?
  • The data light is flashing but the printer is not printing. How do I troubleshoot this problem?
  • When I print large jobs the printer begins to skip labels and drop information. What is wrong?
  • No response to communications

Applies To

Z Series Printers connected to a serial communication device


  • 9 pin Null Modem serial cable or standard 9 pin cable with a Null Modem Adaptor 
  • Printer configurations matched to the host. ZM Serial Communication Information Read More>>

Note: The printer has a 9 pin female connector.


The Z -Series printer comes standard with a 9 pin DTE serial connector. To properly use a serial connection the following parameters must be matched between the host and printer.

  • Baud Rate
  • Data Bits
  • Parity
  • Host Handshake

A NULL Modem cable is required so signals are properly routed between the host and the printer. 

Once properly configured the printer should function without problems as the ZPL (or EPL) data should be received without corruption and the handshaking will prevent buffer overrun. 


  1. Connect the printer and host using the recommended serial cable. Read More>>
  2. Configure the printer to match the host communication settings
  3. Test your application 

Helpful Information for Troubleshooting

ZM Printer Serial Communication Setup Read More>>

The printer can be placed in hex dump mode to diagnose communication issues. Read More>>

If you are using a Windows host you can use the Zebra Setup Utility to check communications Read More>>

View the printer configurations Read More>>  This will verify the printer settings have not changed

If the data light is flashing and the printer is not responding make sure you are sending the correct programming language. Printers will only respond to ZPL (or EPL if using EPL firmware).

Make sure the PROTOCOL setting is set to NONE Read More>>

If large print jobs start fine but then begin to skip labels or miss fields then verify the host handshaking is correctly set.

+ Product Codes

  • Z Series Industrial Printers
  • ZM400
  • ZM600