DsiClock.exe is a Windows Service installed with DSI OpenART that runs in the background on the computer without any user interaction. It continuously monitors the system time and compares it to the value of the high performance counter. If it detects a time drift greater than 3ms in either direction then it sets the system back to the expected value based on the current high performance counter value. 

If DsiClock is running on a computer where the IsSync registry value is set to 1, then it knows that a Sync System is active and it does not do anything. A reboot of the computer is required after the value of the IsSync registry value changes. (See the installation section for the exact location of the IsSync registry value.) 

Note: A sync system is a type of Ponemah and ACQ-7700 set up where the ACQ-7700 is connected to a card in the computer that allows the clock on the ACQ-7700 to drive the system time on the computer.

In order to allow for the user to change the system time when desired, DsiClock will not attempt to reset any time changes if they are greater then 1 minute. Instead DsiClock will allow the system time to change, and it will trigger a card reset to trigger the driver and firmware to reset to the new system time/high performance counter value. 

Also note that it is important that the DsiClock program should take its baseline measurement of the system time and the high performance counter prior to the driver. 

The installation program will also set the registry value under the key: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\dsi2240p\cqcntl$\Parameters\