Labview controlled NI Hardware to output TTL pulses

[easyrider]

Hello

 I have an MCA card that takes TTL pulses to Start and Stop itself. I am looking for a suitable NI hardware that I can control with Labview and when certain condition is met, the LAbview will tell the hardware to output the TTL pulse.

Will NI USB 6501 solve the purpose?

saurabh

[crossrulz]

How fast and accurate of pulses do you need?  The 6501 only has software timed outputs.  This means that your code has to explicitly write a TRUE to the line and then write a FALSE for a positive pulse.  Being software timed, you will not have consistent pulse lengths.

[easyrider]

The MCA card takes TTL pulses, so +5V (FALSE) should do. What I am trying is that Labview checks a temperature controller. everytime the temperature is equal to the setpoint, it will 'ask' the 6501 to output +5V TTL pulse. This pulse will fire up the MCA.

About the stability, i dont know. I have tried it with a DC source of +5V , the pulsing done by touching the output wire to the MCA port. And it works. Please dont ask me to LabVIEW the DC power supply, now!

I dont have the whole manual now, but the related part goes like-

"Start with DigIO Input Dig.4" and then press the start button.
Acquisition will start when you short cut the DigIO port 4 with ground, and
stop when you release the short cut. The DigIO port has a pull-up
resistor to +5V. If you want the opposite behaviour that it should start
with +5V, check "Invert".

This DigIO port is the one I tried with the DC source.

thanks

Saurabh

[crossrulz]

It sounds like the timing of the pulse doesn't really matter if you are doing it by hand with a power supply.  As I stated above, simply write the high value to the DIO and sometime later write the low value.  The 6501 will work just fine.

[Li12345]

Hi, I would like to output TTL pulse to trigger our laser source.  Does USB 6501 work well for this function?  the frequency is less than 1 Khz.  Looking forward to your answer.

Thank you very much for guidance.