PXI 6602 +BNC-2121 +LabView 7.0

[luca75]

Hello,
I am using a PXI 6602 with BNC-2121 Connector Accessory and LabView 7.1 to measure a time in a cams programmer (it is composed by a motor, cams, microswitches. The cams rotate and commutate the microswitch state). I need to use all eight counter but for the moment I set up the program with only one counter ( only one cam). When the measure start I need to count the seconds until the microswitch commutate. In a complete rotation of the cam the microswitch can commutate more times and I need to measure every operation (see Figure 1) and I want to save every time (ti) in a matrix because in a second time I would create a output plot. There is a difficult in this measure: when the microswitch commutate there are a rebound problem. The rebound time (Tr in Figure 2) in negligible respect the cams programmer tolerance and I want eliminate it from my measure. Can Somebody help me to write the program, I am new in LabView world.

Thank you
Luca

[AlessioD]

Luca,

the thing you are trying to do is basically a Buffered event counting using NI-TIO counters. Also you probably want to turn on filters on the input lines to the 6602 counters.
One example to implement buffered counting on all 8 counters with the 6602 with Traditional NIDAQ is found ,a href="http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3DC9F56A4E034080020E74861&p_node=DZ52325&p_source=External>here

Also in LabVIEW, from Help>>Find Examples>>Hardware Input & Output>>Counter Measurements>>Count Digital Events>> you can find solutions with DAQmx for the 6602.
Keep in mind that this device has the possibility of enabling filters on input channels. For details check the DAQmx online Help under Start>>Programs>>NAtional Instruments>>Ni-DAQ>>NIDAQmx online Help

Regards,

AlessioD

[luca75]

Hallo AlessioD, thank you for an answer but I can't reach the link in your post. Can you send it me again?

Regards,

Luca

[AlessioD]

Sorry ;-(

Here you go!

[luca75]

Hallo AlessioD, I read the Digital Filtering Considerations for TIO-Based Devices on NIDAQmx but i haven't understood where i can modify the attributes associated with digital filtering. Do you know it?

bye

Luca

[AlessioD]

Luca,
you can find the digital filtering properties by using a DAQmx Channel Property Node. Drop it on the Block Diagram and browse through all its properties. Yuo will see properties are divided in categories.
You can find the property you are looking for under

Counter Input>>Count Edges>>Digital Filter>>

Look at the screenshot below to see what your property node should look like

Regards

AlessioD
National Instruments

[Kallis]

Hi AlessioD,

I understand that this is an old post, but I'm also interested in using buffered event counting with all the 8 counters of PXI-6624. Is it possible to do this and will there be any DMA issues. Do I need to use some sort of interrupt for counting? Also the link that you send no longer seems to be valid. I would love to read the document that you are referring to.

Actually i'm more concerned because my application requires me to sync all the 8 counters of 6624 with 4472( I will be sharing the oversampling clock of 4472 with the counters).

Thanks

Kallis