ID #1313

How to install virtual COM port driver for Citizen Printer?


A. Introduction

This document is to explain about the virtual COM port driver installation for

  • CT-S281 / 310 / 2000 / 4000 / PPU700II / PMU2xxx II
  • CLP-521/621/631/CL-S700Series.

You may want to use Virtual COM if only USB port is available on the PC and your application software accepts only serial port. Please read this document carefully prior to the actual usage.

B. Condition

  • Operating Systems:
    • Windows2000,
    • Windows XP,
    • Vista (including 64bit)
    • Windows 2003 Sever
  • PC: USB port is available to connect to the printer.
  • Printers:  
    • CT-S281 / 310 / 2000 / 4000 / PPU700II / PMU2xxx II
    • CLP-521/621/631/CL-S700Series using USB port
  • USB port setting is V-COM.

C. Installation steps

This explanation is based on Windows XP but the steps are almost same for other OS.

  • Please set the memory switch 5-3 USB mode for “V-COM”
  • Connect the PC and printer with USB cable while printer power is kept off.
  • Run “Setup” in the folder of driver files.
  • Following Windows shows up. Please press “OK”.

  • “Software Install” window shows up.

  • Please press “Continue Anyway”.
  • Then “Hardware Installation” window show up.

  • Please press “Continue Anyway” and repeat this once more.
  • Turn the printer on. Then the Wizard below shows up.

  • Please choose “Install the software automatically” and press “Next”.
  • Then “Hardware Installation” window show up.

  • Please press “Continue Anyway” and repeat this once more.
  • Then driver installation is finished.

Note: Please reboot the PC. (Recommended)

  • Please check if the driver is installed correctly in the “Device Manager”.
    • 1 Port is added (Either COM7 or COM8)
    • CITIZEN SYSTEMS Virtual Communication Port” is added to USB Controller.

  • Please set “Bits per second = 115200” and “Flow control = Hardware” in port setting (Recommended).

Uninstalling the Driver:

  1. Go to Start > Control Panel > Add or Remove Programs
  2. To delete the driver, please choose “ctvrcom”
  3. Press “Change/Remove” button. Then Uninstall window shows up.
  4. Please follow the instruction.


COM port assigned by the driver installer is fixed by the model (USB ID)

  • COM7 = CT-S281/PMU2xxxII/PPU-700II (VID:1D90, PID:0FFF)
  • COM8 = CT-S2000/4000/310/CLP-521/621/631/CL-S700Series (VID: 2730, PID:0FFF)

If you want to assign other COM port, please contact Citizen Support Center. 


For more detail please visit:

Tags: Hardware Settings, Print

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