Hello, I'm having trouble using PID control on an flow valve that requires a 0-12VDC power source. My setup includes an Agilent 34970A with a mulitfunctional module to output power to a Kepco power supply which ouputs power to the flow controller. The only way I can get PID to work is if I use a very small Gain such as (0.2), an Integral Time of (-.49) and a Derivative Time of (.005). It seems to dial in the flow meter within 2-3 minutes but it doesn’t seem right to put a negative value in for the Integral Time though?? I'm wondering if it has something to do with the hysteresis of the flow meter. Have you guys heard of anything like this happening with PID on a control valve? Please let me know. Thanks, Jeff Flow controller manf: Teknocraft~Standard proportional control valve. http://www.teknocraft.com/pdfs/proporvalve1.pdf

Hello,The driver for the HP 34970A can be found in our Instrument Driver Network at www.ni.com/idnet. Here is the link for the driver. In addition to the forum post linked by muks, check out the following Developer Zone.NI Developer Zone Tutorial: Complete resources for a PID control system with NI M Series devicesFYI, you will communicate with the HP 34970A via GPIB or Serial communication. Thus, the underlying driver will be either 488.2 or VISA (respectively). If you decide to go with a NI M-Series device, the driver used will be NI-DAQmx.

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PID Troubles on a Flow controller???

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PID Troubles on a Flow controller???

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