How to generate a delayed retriggerable pulse using only one counter with PXI 6070E card

[ElvisMarcy]

Hi

I have a problem in generating a retriggerable delayed pulse with a single counter(triggered through a signal at gate) using PXI 6070E card. VI was developed in NI LabVIEW traditional DAQ Ver.7.1. I have used the "delayed pulse generator config" VI and a "Start counter" & "Stop counter" VIs for the purpose. But there is no output seen at the out terminal of counter. So I introduced a "wait" VI and set it to 1 sec. Now the pulse output appears but some pulses are missing mometarily after every 1 sec interval. (any solution for this)

I have gone through a few similar requests in the forum but they suggest either to use two counters or to generate a finite pulse train which does'nt fit my application. Moreover PXI 6070E has only 2 counter timers. I am already using one counter to measure the frequency of a pulse train(signal 1). The application requires to generate a delayed retriggerable pulse for every pulse in signal 1. So I have only one counter left.

Can I measure the frequency of signal 1 by analog means.? so that I can use two counters for pulse generation. (Signal 1 is a TTL signal).

Request some help.

Thanks in Advance

Regards

[R Sandoval]

Hello Kalyan,

You may want to refer to the following example:

Using One Counter to Generate a Retriggerable Finite Digital Pulse Train with a PCI-6602 and DAQmx

Although you can measure the frequency of your signal using the analog input, this setup is not typically recommended.  Doing so will require setting a voltage threshold which will be used to enumerate the count in software and may become CPU intensive and error prone.  Furthermore, the sample rate of the analog input is 1.25 MS/s whereas the counter uses the internal time base of 20MHz or an external clock.

[John_P1]

A finite pulse train (N_Pulses >= 2) does require the use of 2 counters on most of our older hardware including your 6070E.  If you're just talking about generating a single retriggerable pulse, you would only need one counter.

Here's an example in Traditional DAQ that shows you how to set a retriggerable pulse generation (it also allows you to adjust the characteristics of the pulse on-the-fly).

If you're writing a new program, you might consider switching to DAQmx as it supports NI's latest hardware and recent OSes should you ever need to upgrade.  Traditional NI DAQ is no longer in active development.  Here's an example of how to implement a retriggerable pulse generation in DAQmx.  You should take note that you can't use the two drivers to simultaneously talk to the same piece of hardware, although you should be able to go back and forth by resetting the Traditional DAQ driver before switching to DAQmx.

Best Regards,