DIO 6533 Question

[Marshall GaTech]

I have a pci DIO-32HS card, which I have wired (using a SCB-68) such that there is a binary number coming in as the input lines for port A, and I also have a strobe signal as an input. I have two questions:

1. What pin should the strobe signal be wired to, so that every time strobe goes high I have the card read the input on port A and convert it to a number. I only want the data read on the rising edge of the strobe signal, and not again until the next rising edge.

2. How would I implement this using labview? What vi's and settings should I use?

Thanks in advance for all the help.

[Russell]

Thank you for contacting National Instruments.

There is actually a LabVIEW/NI-DAQ shipping example that covers this called "Buffered Pattern Input.VI". You can search for it by going to the Help menu and choosing Find Examples.

In the documentation of the VI you will find I/O connections information as well.

I hope this helps!

Russell
Applications Engineer
National Instruments
http://www.ni.com/support

[Marshall GaTech]

I have been trying to get this to work and still cannot. Is it possible for you to help me with the specific settings that I need to have in the vi? I obviously need to use an external clock, and the clock is asynchronus. I also set it up for the correct device and port numbers, and I know the card works because I have tested/configured it in MAX. However whenever I run the vi, and then apply power to the strobe line (connected to REQ1 because I am trying to read port 0/A) nothing happens the vi still sits there. Any help?

Thanks again.

[Russell]

In asynchronous mode the VI will continue to run until all the samples in the buffer have been acquired. So, if you have a buffer size of 100, the VI will wait until 100 pulses go by on the REQ line before finishing. I have a PCI-DIO-32HS working with an external clock, asynchronous mode and default values for the other controls on the VI and the clock connected to REQ1 (pin 2). You might want to verify that your strobe signal is present with a scope or counter. Also, is your strobe faster than 20 MHz?

Russell

[Marshall GaTech]

I seem to be able to get everything working now, however I'm still confused by the fact that "pattern generation w/ external clock" is the setting used. It seems that it would be more fitting to use the "change detection" setting since my strobe is esentially a completely random signal. Maybe I am just confused about this as well though. I appreciate your helpfulness. Thanks.

[Russell]

Hmm, I'm not sure why "pattern generation w/ external clock" is the constant used to specify external clock. It should be "I/O Connector". I guess that since DIO Config already specified the operation as input, the "pattern generation w/ external clock" constant works too.

Sorry for the confusion.

-Russell