Proportional Valve delayed signal

[LeBendAll]

Hello,

I've recently installed a proportional valve onto our machine. For now I am using a slider to control the voltage sent to the valve. The time delay set on the PWM controller is 1.5 seconds. For the first few minutes of running the program, the time delay is accurate. However as the program runs the delay is increased. Can someone please advise on how to correct this issue? I have attached the program in question.

Thanks

[CJ_Butler__DASYLab_Pro]

It's possibly a driver issue. Please contact Measurement Computing directly at www.mccdaq.com. You can email in a request, or call it in to 508-946-5100. 

You will need your DASYLab release number, the version (lite, basic, full, pro, runtime), the version of InstaCal, the version of the MCC-DRV driver (see the DASYLab Help menu, MCC-DRV, Driver Information).