I have a portable data aquisition application on a laptop using Wonderware as the HMI. Currently I am bringing in Temps and D/Ps, but to control the D/P I have to manually adjust the valve(s). I have found an electric actuator for the valves that recieves a 0-10Vdc input signal and National Instruments NI DAQCARD-6715 will produce up to 8 analog outputs. I just not sure how to make the two talk (Wonderware & DAQCARD) and incorporate PID for the valves. Any help would be appreciated.

 

ANSWER: In the NI configuration utility, Measurement and Automation Explorer, check to see that the OPC server is on. You can download the NI Server Explorer to see the OPC server in action. This is at www.ni.com/support. Once the OPC server is working, Wonderware should be able to see the I/O points.

Contact our support group if you are still having challenges.

Preston Johnson

 

Cautions regarding NI-DAQ PCB's; on computer or power reset the control outputs (pull downs of small pull-ups) can be at indeterminate levels. I always placed pull-up on controlled device, so logic high would be present independent of NI-DAQ state at reset, and logic high was the prefered (safe) mode of the device.