Re : Square very low frequency signal

[scls19fr]

Hello,

for an experiment I need to send to a device a low frequency square signal.
In fact I would like to be able to set the high level delay and low level delay.
I don't think the "simulate signal express" can fit to my needs.
I believe that I should use a sequence inside an infinite loop while.
The first sequence
 set output to 0 (a numeric float constant)
The second sequence
 wait x seconds
The third sequence
 set output to 100 (a numeric float constant)

and so one

But I don't know if it's a good way to do like this...

Any idea ?

I also encountered a problem when I try to send the 2 constants (0 and 100) to a display.

I don't know what I should do.

I hope you can help me

Best regards

[Richard_KEROMEN]

Hi,

I think your solution is a good one, it allows you to set all the parameters you need. Have you tried? does it work ?

Regards

[scls19fr]

I don't think so !
The problem is that if I want to stop the sequence (because as I said it before... it can be quite long !) I can't.
Sequences can't be break !
See my posts on LAVAG forum
http://forums.lavag.org/Generate-my-own-input-signal-for-a-device-t10532.html
http://forums.lavag.org/Break-abort-a-long-sequence-t10544.html

I wonder if I shouldn't use
Express / Input / Simulate arbitrary signal
(not sure of the translation because in french it's
Express / Entrée / Simuler un signal arbitraire)

[Richard_KEROMEN]

Hi,

I suggest you to use a State machine, if it's not already done. See the exemple given in the link below.
Hope it will fit your spec.

Regards

[scls19fr]

Sorry but I can't try your vi with your DAQ board !
Moreover I wonder if using a state machine is a good solution because what should I do
if I want to change the square for a sawtooth signal ?

Best regards

[Richard_KEROMEN]

Hi,

Have you solved your issue? Did you find a solution?

Regards

[scls19fr]

Yes I use the VI Express / generate abitrary signal
All the VI are in my SVN repositery
http://svn.berlios.de/viewcvs/openphysic/labview/turbo-wrenturbines
svn checkout svn://svn.berlios.de/openphysic/labview/turbo-wrenturbines
see trunk/input dir
I like this VI Express instead of using sequences because I can easily stop it.
(because breaking/abording a sequence doesn't seem easy)