Reseting a DAQ after test

[LABMAT]

Dear all,

I have a test application - where upon completing the test procedure, the user is asked to switch off the test jig.
I am using a PCI 6536 and USB6008 device.

The PCB I am testing has around 32 LCDs. the circuitry is such that they are connected via SIPO chips (Serial In Parallel OUT). the device that controls these lines is the PCI 6536. wht I have found is that most of the time, after the test, if the user does not switch the device OFF, and he connects another board to test, these data lines are held in a random state and the LCDs display gobbledigook....

I found a way around this by reseting the DAQs after the test procedure and a power cycle clears the problem.

HERE IS MY QUESTION:

Will the DAQs be affected / damaged if they are constantly reset like this? At any one time, there will be more than 20 boards that would be tested indivually.. and I reset the device at the start as well as the end so that makes it more than 40 resets (2 reset for each board).

Any advice is invaluable.

thanks,

Labmat.

[LABMAT]

any idea guys?

Thanks,

Labmat

[MariaMK]

Hi Labmat,

First of all I would like to clarify the issue you are facing. You are testing a PCB which has 32 LEDs (not LCDs?). Each LED is connected to a separate channel on the PCI 6536 via a SIPO chip. When the test is finished you programmatically reset the 32 channels on the PCI by sending a value to them (probably a digital low?).

If the above is correct, there shouldn't be an issue with continually resetting the signals when the test is done.

[JB]

Do you use DAQmx Reset Device.vi ?

If yes, why do you not set the state of the DOs to low with DAQmx Write.vi ?

[LABMAT]

hi JB,

yes you are right. I am using DAQmx Reset Device.vi.

I call this vi when the test starts and also at the end of the test.

I could write a logic 0 to all the data lines and that could work...

But I want to know if continuous reseting the devices like this is gna cause the device any harm.

BTW, the reset devices vi is only called twice in a test (start and end). It is not in a loop running forever.

thanks,

Kind Regards,

Labmat

[LABMAT]

Hi MariaMK,

Thanks for the reply.

No, Im not driving 32 LEDs, Im driving 32 LCDs

Thanks,

Kind Regards,

Labmat

[MariaMK]

Hi Labmat,

Continually resetting the device will cause no harm to the PCI 6536. All the best with your project 🙂

[JB]

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MariaMK a écrit :

Hi Labmat,

Continually resetting the device will cause no harm to the PCI 6536. All the best with your project 🙂

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...but this is not the best way to solve this task and it will not be possible to use this technique generally.

Therefore I strongly encourage you to take good habits for your applications.