TTL DOWN detection and generating

[mozdas]

Hello,

I was proceeding 2 simultanous signals from Labview which go to different instruments. 

One signal is like dirac delta function, very sharp positive part of cosine function and one TTL.

Both are at the same frequency but duration could be adjusted.

Now I want to have TTL signal from another device, which will be connected to a digital input of DAQ (NI 6211), when TTL is Down, the other signals will be on for predefined duration. The frequency will be based on external TTL which will come from a signal generator.

I added the Labview program and the signals that I need. Basically, there will be a master TTL signal connected to input of DAQ and when TTL down is detected, 2 signals will be generated to output for defined durations fore each and the freaquency will be based on master TTL signal.

Any help will be appreciated. Thank you.

[Christoph_D]

Hi,

in your example you use analog inputs although your applications sounds like you have digital inputs (you mentioned TTL).

(BTW your explanation and the sketch is not very detailed and structured, so perhaps I missunderstood your question)

if you want to output a signal with a exact timing between trigger and output it very much sounds you want to look into Counters. You might want to to use a Counter Output Frequency task where you use a input as a digital start trigger and define the desired delay between trigger and generation.

Please also have a good look into those resources:

Using Counters and Digital IO
http://www.ni.com/academic/students/learn-daq/digital/

M Series User Manual
http://www.ni.com/pdf/manuals/371022l.pdf

Best regards,
Christoph