Can I use an external clk and an external digital trigger both at the same time on a PCI-5105 digitizer

[B Cox]

I would like to use 4) PCI-5105 digitizers in 4 different computers (all in the same rack, but separate chassis). I would like to sync the sample clock on all of them, and would also like to simutaneously trigger each board. I only see a single digital IO (PFI1) line. I see how I can use that line for either of the functions, but how do I do both at the same time?

Also, do I understand correctly that I the 5105 can acquire data, and fetch records at the same time. I would like to config the board to take a large number of records, and then start downloading them while the acquisition continues. Will this work, and will I still be limited to the number of records that can fit in the on-board memory, or can a circular buffer be used to allow a near-continuous acquisition of records.

[Sean_C.]

Hello B,

Are you acquiring with all 8 channels?  If not, you can use one of your unused channels as an analog trigger source, and input your digital trigger there.

Alternatively, the PCI-5105 has a RTSI connector on the rear of the board.  This connector gives you access to 8 digital RTSI lines which can be used for digital triggering.  See the following KB for more information about RTSI:

http://ae.natinst.com/operations/ae/public.nsf/web/searchinternal/ad2d553f55a07bbf8625650d005f1f00?O...

You are correct.  You can fetch data while an acquisition is in progress.  And you can fetch more data than will fit into memory provided you set the Enable Records > Memory property to true.  Take a look at the "niScope EX Fetch In Chunks.vi" and "niScope EX Multi Record Fetch More Than Available Memory.vi" shipping examples in:

C:\Program Files\National Instruments\LabVIEW 8.2\examples\instr\niScope

I hope this helps.

Regards,
Sean Close

Product Support Engineer: High Speed Digitizers

[B Cox]

Thanks for your reply.

I need to use all 8 channels, dedicating one as a trigger will not work.

Can the RTSI bus be extended to boards that are in different computers? (I could not get your KB link to work, and was not able to find any other general overview of RSTI on the NI website) I plan to have 4) PCI-5105 boards in 4) separate computers with different backplanes. The computers will all be mounted close to each other, but in separate chassis.

[Sean_C.]

Sorry about that... Try this link:

http://digital.ni.com/public.nsf/websearch/AD2D553F55A07BBF8625650D005F1F00?OpenDocument

You will not be able to connect these boards with a RTSI cable.  The RTSI cable is not that long, and you need to have all boards within one system for that to work.  You can however still set the digital trigger source to a RTSI line, and externally wire your digital line to the correct pin on the RTSI connector.  This will require some external wiring as we do not provide any kind of connector block for the RTSI lines.