Firmware & Software Versions

AC-PRO-II® features a USB port that allows firmware to be updated in the field, using a Windows PC and our free InfoPro-AC® software.  Firmware update instructions are included in the
InfoPro-AC® Help Menu.

AC-PRO-II® Firmware

The list below includes firmware version highlights.  If you need to update firmware, please contact URC for firmware files.

For AC-PRO-II®, your existing firmware version can be displayed on the AC-PRO-II® screen by pressing the “MORE” button when at the main readings screen.  Refer to the AC-PRO-II® Instruction Manual for additional details.


Version highlights / summary


  • Added "special purpose" Modbus registers 7072-7076, which provide current values down to 2% (accuracy is not guaranteed below 10%)
  • Improved voltage measurement capabilities (in the event of a Ground Fault on a non-solidly grounded system - applies to AC-PRO-II with VDM only).

  • Firmware Release Notes and FAQ
  • Added Phase Loss / Reverse Protection feature ***
  • Added “Test Mode” for testing convenience.
  • Added Line-to-Line Voltage measurement, and removed Line-to-Neutral voltages (for AC-PRO-II with Voltage Divider Module).
  • Improved UnderVoltage protection ***
  • OverVoltage and UnderVoltage now have dedicated pickup settings and delay settings for both Trip and Alarm features.
  • Improved Modbus Communications reliability
  • Added Ground Fault Alarm feature
  • Added Ground Fault Test trip function
  • Added Frequency Measurement
  • InfoPro-AC v2.0.36.0 or later must be used with firmware v2.0.19.0 and later.
  • ***Phase Loss / Reverse feature and improved UnderVoltage require AC-PRO-II with VDM rev 2 hardware, which is present in AC-PRO-II with VDM units shipped 2016 & later
Initial v2.0 shipped Nov. 2017


  • Added I^5t slope options to ground fault protection.
  • Line-to-Line voltage values are now available over Modbus communications. 
  • Improved Alarm relay manual reset functionality.
  • Reduced possibility of reporting incorrect breaker clearing times if limit switch is mis-wired or not wired.


  • Increased maximum CT rating from 5000A to 6300A.
  • Added capability to allow InfoPro-AC to display breaker position if limit switch is wired in. 
  • Neutral overload trip times are now based on Neutral CT secondary setting, not Phase CT secondary setting.
  • Improved trip times for low current Short Time power-up trips (power-up delay was present only in v1.7).
  • InfoPro-AC v1.1.10.0 or later must be used with firmware v1.8.


  • Misc modbus communications fixes related to status, system date/time, consistency in current scaling.
  • Improvement to clearing time measurement for low current power-up trips when using 52a or 52b (limit switch) method.


  • Added ability to fire Siemens ST II and ST III, and Westinghouse DS actuators (requires AC-PRO-II hardware version shipped after 7/1/15).
  • Addressed intermittent display flicker issue on initial USB power-up.
  • Improved OK LED error logic.  Added "Sluggish Breaker" as reason to turn OFF the OK LED.



  • Eliminated possibility of GF type being set to Return over communications (while NOL is set to ON).
  • Improved sluggish breaker screen logic when 52a or 52b limit switch is used.



  • Fixed Modbus power registers 7062 and 7068, and Quick Trip register 7103.
  • Improved compatibility with existing LCI web-page.
  • Eliminated possibility of Display being powered up before trip unit.


  • Initial AC-PRO-II firmware (first release)


InfoPro-AC Software for AC-PRO-II

The list below includes software version highlights.


Version highlights / summary


  • Plotting Time Current Curves (TCCs) with Test Results
  • Input and document Breaker Test Results
  • Input and document “As Found” and “As Left” trip unit data
  • Print and Save Test Reports
  • Perform RS-485 Modbus Communications test

  • Updated for compatibility with AC-PRO-II v2 firmware

  • Increased maximum CT rating from 5000A to 6300A. (requires AC-PRO-II firmware v1.8 or later).
  • Added ability to display Breaker position in Readings tab, based on limit switch. (requires AC-PRO-II firmware v1.7 or later).
  • Ground Fault current RMS value is now displayed in Trip History tab.
  • USB connectivity improvements.
  • Other miscellaneous minor improvements.

Initial Release

Download the latest version of the InfoPro-AC, AC-PRO-II Software Application


ISO 9001