Writing Digital Patterns

[TP Cytyc]

I am trying to write a digital pattern at 5kHz to a digital line using
Labview. Software timing only allows 1kHz from what I can tell, so I
was trying to use one of the clocks on one of my devices. I've tried
almost every device and can't seem to get the sample timing to work. I
want to take an array of bool and feed that one by one at a specfic
rate to a digital out. The devices I have at my disposal are PXI 6289,
PXI 4461, PXI 6515, USB 6009, USB 6016. Can any of these do what I want
it to do? It seems like a simple problem, but I can't seem to get
anything to work.

Thanks,
Tim

[praiselight]

The LabVIEW example you mentioned worked fine on my 6251 card when
using port 0 exclusively. Anyway, I would like to use the ports P1 and
P2 (in either PFI or static mode) to generate and acquire digital
waveforms, too. LabVIEW complains, that these ports are not able to run
buffered operations.

I've been through some forum posts and have read many manual pages, but
I still I don't understand how I can generate a waveform (e.g. to
communicate with peripheral hardware) and aquire a response, without using
an external clock (I need to use one-wire communication with a
microcontroller). And I didn't get the message why and how to use
PFI-Ports except, that they are intended for timered applications. I
would appreciate any hint.

In the attechment you can see the application, that I would like to move to the PFI-I/Os.


ReadControllerMemory.zip:
http://forums.ni.com/attachments/ni/70/5003/1/ReadControllerMemory.zip

[McKala[DE]]

Hello Tim,

Port 0, as you discovered is the only port on the 6251 which can
preform correlated digital I/O.  Port 1 and 2 employ static
digital input and output which means every
digital read
or write the board performs must be initiated by a software command and
on receiving the command the lines or ports immediately inputs or
outputs a pattern.  I don't think this is what you have in mind.

You could  generate a pulse train using one of your counters and
route the output of the counter to one of the PFI lines to be used as
an external clock.&nbsp; The <a href="http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=FD8B9065A13F29FAE0340003BA7CCD71&amp;p_node=201195&amp;p_source=External" target="_blank">M Series Hardware-Timed DIO with Counter
Clock Generation</a> example demonstrates this.

Let us know if you have any questions about this VI!

Regards,
Message Edited by McKala[DE] on 06-07-2006 08:39 PM