Communications test from DOS

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.

  1. First you need to determine the method of communication.  The 2" printers will only have a serial (COM) or parallel (LPT) port available, not both.  4" printers usually have both.
  2. If you are using a serial port, you need to set the communications settings in DOS to match the printer.  To determine the printers communication settings, run the autosense procedure.  The settings for Baud Rate, Parity, Data Bits, Stop Bits, and handshaking method will print out on your configuration label.
  3. Next you need to determine which port you are using on the PC.  If you have a parallel port on the printer then you simply connect the parallel cable to the Parallel or Printer port on the PC.  If you are using the COM port, you need to determine which port is available on your PC.  Most PC's have two COM ports, numbered COM1 and COM2.  There are usually 2 additional ports, COM3 and COM4 used by internal devices like internal modems.  The com ports are paired, so you cannot use COM3 and COM1 at the same time.  Same for COM4 and COM2.
  4. Start your DOS or COMMAND session by going to Start, Run and typing Command or CMD depending on your operating system.  If communicating Parallel (LPT), skip step 5.
  5. To set the DOS communication settings (assuming default settings on the printer and using COM1) start the DOS or COMMAND session, and at the prompt type:

  6. At the prompt:
  7. You should now see the Editor screen:

  8. Next, push Enter, which should move the cursor down on line, then type the upper case U and then Enter again.  You should now see:

  9. If your printing to the parallel port, select File then Print and the command to print a configuration label will be sent to the printer.
  10. If your using the COM1 or COM2 port, selection Options, then Settings and select COM1 or COM2, then select File then Print.
  11. If you see a configuration label print, you have confirmed the printer, cable and PC port are working correctly and the problem is likely in the software application.