Wrong signal statue of GateValve

[donga38]

Hi everybody.
I hope someone can help me with the problem I am trying to solve. We are using the NI PCI-6517 to control the automatic opening and closing of the Gate Valves (G.V.) in the vacuum system.
Usually, if the status of the G.V. when no action will be "closed". But after a sudden power failure one day, the state of one of those Valves changed. The status changed from "closed" to "open" and vice versa. I have tried to duplicate a valve with the same effect (which is working correctly) to replace it. But still no working. I also thought the old pin in the used NI 6517 was broken, so I changed it to a new pin location. And I made change Line channels too. But the result remains unchanged.
I don't know if this problem can be solved by fixing the code or status on LabVIEW or if we have to replace a new Ni PCI-6517.
I hope that there is someone who can help me out...
Thanks a lot!

[santo_13]

Please provide more information about this "valve" and how is it connected to the PCI-6517 and other external circuits involved.

If you disconnect the valve and check the voltage levels for the DO pin when you write a Low or High, does it match?

[billko]

I have a hard time believing it is the software, although this is based upon the assumption that the original developer used LabVIEW best practices when developing the code.

[donga38]

Please provide more information about this "valve".

=> We use two types of valves: Pneumatic Valve to separate, let's say, chamber 1 and chamber 2. We use a Compressed air Solenoid Valve to control the  "CLOSE/OPEN" status of Pneumatic Valves.

how is it connected to the PCI-6517 and other external circuits involved? 

=> We need to use LabVIEW to send the signals to a Compressed air Solenoid Valve to close/open the Pneumatic Valves. So it means that the signals are sent when we click the mouse in LabVIEW => sent through PCI-6517 to Solenoid Valve =>  CLOSE/OPEN Pneumatic Valve. 

If you disconnect the valve and check the voltage levels for the DO pin when you write a Low or High, does it match?

=> the Voltage is a bit increased now. From 24V => 25.8V.

[donga38]

Yes, I am thinking about the Mechanical problem. So that I am not sure if it is the PCI or the valve itself has a problem... I need to change one of them to check anyway... 

[donga38 · Accepted solution]

hi everyone,

We solved it. It is actually because of the solenoid valve problem. 

Thank everyone who gave us advice on what to do.