Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Mute
- Printer Friendly Page
6602 counting pulses on all 8 counters
Nick_H
Member
03-23-2005 05:12 AM
Options
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report to a Moderator
I need to count the number of pulses on 8 lines simultaneously.
Each line will have a burst of 2MHz pulses.
Can I do this on a PCI-6602 or will this need to be a buffered operation that will be limited by the available DMA channels.
Also how many of the 32 digital I/O lines are used by the counters, if I use all 8 counters how many inputs will be left over for digital i/o use.
Any help appreciated
Nick
Each line will have a burst of 2MHz pulses.
Can I do this on a PCI-6602 or will this need to be a buffered operation that will be limited by the available DMA channels.
Also how many of the 32 digital I/O lines are used by the counters, if I use all 8 counters how many inputs will be left over for digital i/o use.
Any help appreciated
Nick
Kevin_Price
Proven Zealot
03-23-2005 10:10 AM
Options
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report to a Moderator
Nick,
Good news -- if you only need a total count for each of the 8 channels, you could perform unbuffered edge counting without requiring any DMA. When the bursts of activity have finished, you simply read the count stored in each counter.
Counters 2-7 share their i/o pins with DIO 8-31. Counters 0 and 1 do not share and DIO 0-7 do not share, so you always have at least 8 DIO lines available for use.
I recall that under traditional NI-DAQ, there were ways to operate DIO on some of the counter lines that weren't needed in their tasks. It took a little care to setup properly, but you may be able to free up a few more DIO that way. Counters 2-7 need their Source pins for their counting tasks, but their Gate and Aux pins should be available though possibly only as inputs. Output pins may also be available, but I'm less sure about that, and they may be restricted to output.
I haven't tried this under DAQmx, but I kinda suspect it might wind up being a bit simpler to setup.
-Kevin P.
Good news -- if you only need a total count for each of the 8 channels, you could perform unbuffered edge counting without requiring any DMA. When the bursts of activity have finished, you simply read the count stored in each counter.
Counters 2-7 share their i/o pins with DIO 8-31. Counters 0 and 1 do not share and DIO 0-7 do not share, so you always have at least 8 DIO lines available for use.
I recall that under traditional NI-DAQ, there were ways to operate DIO on some of the counter lines that weren't needed in their tasks. It took a little care to setup properly, but you may be able to free up a few more DIO that way. Counters 2-7 need their Source pins for their counting tasks, but their Gate and Aux pins should be available though possibly only as inputs. Output pins may also be available, but I'm less sure about that, and they may be restricted to output.
I haven't tried this under DAQmx, but I kinda suspect it might wind up being a bit simpler to setup.
-Kevin P.
CAUTION! New LabVIEW adopters -- it's too late for me, but you *can* save yourself. The new subscription policy for LabVIEW puts NI's hand in your wallet for the rest of your working life. Are you sure you're *that* dedicated to LabVIEW? (Summary of my reasons in this post, part of a voluminous thread of mostly complaints starting here).
