AN-013 – Resetting a Controller to Factory Defaults

If you need to reset your Arroyo Instruments controller to factory defaults, two methods are available: one, if the controller has a user interface (display, knob, buttons), you can do a power-on reset; or two, you can use a software program to reset it over the computer interface.


To perform a power-on reset with units that have a user interface, do the following:

  1. Make note of any settings you want to restore after the reset, especially any safety limits
  2. Turn the AC power switch off
  3. Press and hold the following buttons:
    1. For controllers with an adjustment knob, press and hold both the knob and the MENU buttons
    2. For controllers without an adjustment knob, Press and hold both the On/Off and the Menu buttons
  4. While keeping both buttons pressed, turn the AC power switch on
  5. Continue to hold both buttons until you see the serial number displayed (doesn’t hurt to hold them longer)
  6. Release the buttons
  7. Instrument should display a W-803 message, “User reset unit to factory defaults”

The unit now reset. Go into the menu and restore any of the safety limits (current, voltage, temperature, etc.) as well as any other settings to restore the controller to proper operation.


If your instrument does not have a user interface for local reset, or you simply want to reset the unit remotely, visit the Download Center on the Arroyo Instruments web site and download Arroyo Instrument Reset , found in the Software section towards the bottom of the page. Start the program, select the COM port, and click Reset.

If you are writing your own programs (or using a terminal program like ArroyoTerm), you can also send a *RST command.

While not always required, rebooting the unit with a power cycle will ensure a complete unit reset.

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