huge delay when PCI-6534 starts

[Vasilich2004]

Hi,

To simplify my question I used standart example - Buffered Pattern Output.vi . In the example DIO Start.vi (Actually Digital Buffer Control.vi) gives huge (> 200 msec) delay.

Currently, I used module in internal clock. I will use with external clock.

Please, any ideas!

Andrei.

P.s. could you, please, administrator delete the same message in LabVIEW thread.

[Vasilich2004]

I did the same test with external clock. Fortunately, I used loop.  Scope showed that DIO Start.vi doesn't eat time. But more precise test showed that DIO Start.vi eats > 200msec in first cycle.

I still don't feel well how the module works.

At first, it requires to have memory in the host. But I don't use it.

At second, in each cycle I need to use Config -> ... -> Clean resource.

At third, it looks the module doesn't like to work continuously with internal clock.

Thanks, Andrei.

[Abhinav T]

Andrei,

It looks like you are using Traditional DAQ to program your 6534 - is there any reason for you to do so? There is a newer driver out for the 6534. Here is a link to the newer driver.

As per your inquiry I believe this forum post may shed some light on this matter.

Hope this helps!

[Vasilich2004]

> It looks like you are using Traditional DAQ to program your 6534 - is there any reason for you to do so? There is a newer driver out for the 6534. Here is a link to the newer driver.

Because there is enough big program was written someone. I need just add some features. Actually, DAQmx (not the latest) was installed. But I don't see this card in DAQmx area by M&A program.

>As per your inquiry I believe this forum post may shed some light on this matter.

This is not my case. This thread talks about updating buffer on the fly. I need more simple loop load waveform, regenerate some times and stop.

Any another help???

[Sandra_T]

Hello  Andrei,

Thank you for posting to the discussion forum. You are correct, the PCI-6534 is supported by both the Traditional DAQ 7.4.1 driver and the DAQmx 8.3.1 driver. I understand that you already have substantial code that is already written with the Traditional DAQ driver, so you don't want to switch over. There are benefits to switching over. Take a moment to look over this document about converting your Traditional DAQ code to DAQmx:

Transistion from Traditional NI-DAQ to NI-DAQmx

Learn 10 functions in NI-DAQmx and Handle 80 Percent of Your Data Acquisition Application

You mentioned that the device doesn't appear in MAX, one thing you can try is to go into your Windows Device Manager and then find the card under Data Acquisition Device. Right-click on the device and then chose to update the driver. This should run the New Hardware Detection Wizard and this will update the driver for this card, now it should appear in MAX. Also make sure the the DAQmx driver is 7.4 and above. The card was not supported until the DAQmx 7.4 driver release. Also remember to refresh MAX, by pressing F5.

With regards to your other question about the PCI-6534 and the Buffered Pattern Output.vi shipping example taking a long time to execute, more specifically the DIO Start.vi. If you want to learn about how the module works, you can refer to the 653x User Manual for Traditional DAQ. On page 2-12 of the document it explains repeat generation of data by enabling onboard memory looping.

The 653x will require some time to configure, write the data to the internal transfer buffer, start the task etc. Take a look at Appendix E of the user manual linked above to get Maximum transfer rate and benchmark values for data transfer.

It would be helpful if you can tell us more about your application and what you want to do. For instance, in your code are you continuously cycling the configure task, start task, and end task?

Regards,
  Sandra T.

Applications Engineer | National Instruments