Changing the Duty Cycle (PWM) with buttons

[fusion2022]

I have to generate 6 PWMs. It is possible to use only one timer?. I have done this file but only 4 timers appeared, and I should like use 3 to other purposes. (Note: I can not post a new thread)

[Bob_Schor]

I only recently started using Counter/Timers (I'd been in the "analog" world up until recently), and really started to admire them.  However, I think found that (a) most NI DAQ devices have "too few" Counter/Timers, and (b) some configuration require pairs of Counter/Timers (as I learned when I could create one pulse when/where I wanted it, could create a second as well, but if I wanted to control pulse frequency, width, and initial delay, this required a pair ...  Sigh.

You might look at/for NI's 6602, which comes as a PXI or PCI board, and has 8 Counter/Timers.  Maybe NI has something else out there ...

Bob Schor

[Kevin_Price]

I'm guessing you may have an X-series board -- they have 4 user-programmable counters.

It sounds like you want 6 counters for generating PWM and another 3 counters for other purposes.  Is that right?

Bob Schor's suggestion of a dedicated counter/timer board is a good one, but there's a newer generation version that improves on the 6602 in several different ways (bigger FIFO, hw-timed DIO support, finite pulse trains with only 1 counter, more flexible digital filtering, and more).  Check out the PCIe 6612 (also available in PXIe).

If you need to sync the 6612 counters with the X-series board you already seem to have, you should install a RTSI cable between them and configure MAX accordingly (so DAQmx can do auto-magical timing signal routing, once it knows they share a timing signal bus).

-Kevin P

[Bob_Schor]

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@Kevin_Price wrote:

Bob Schor's suggestion of a dedicated counter/timer board is a good one, but there's a newer generation version that improves on the 6602 in several different ways (bigger FIFO, hw-timed DIO support, finite pulse trains with only 1 counter, more flexible digital filtering, and more).  Check out the PCIe 6612 (also available in PXIe).

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Oooh, I want one ...

Bob Schor

[Kevin_Price]

Oh yeah, one more big improvement -- buffered pulse train generation!  (Something I had complained about / requested for about a decade worth of using the 6602.  It came around with the STC3 chip in the X-series MIO boards, a couple years after I stopped doing apps that needed it.)

-Kevin P

[fusion2022]

I am programming a NI-USB-6341 that has 4 timers

I should like program several PWMs at the same frequency and other using different frequency and made following program:

[IMG]http://i65.tinypic.com/ogan4m.jpg[/IMG]

But I have to use the 4 timers to have only 4 PWMs.

Is there a possibility to use the same counter for several PWMs?

[Kevin_Price]

Same question you asked before and has been answered over here.  I'll follow up in that original thread...

-Kevin P

[Kevin_Price]

General answer:

1 counter can be used to make no more than 1 output signal (some counter tasks use less than 1...).   You cannot make 2 or more distinct output signals with 1 counter.

If you want several of those output signals to be *identical*, then you *might* be able to simply physically wire 1 single counter output signal to multiple destinations.  Be aware that counters can only source a very minimal amount of current natively so there's no guarantee that 1 counter will drive several of your external thingies at once.

-Kevin P