generatig double pulse signal

[satriany]

Hello everybody,
i'm trying to generate a signal with double pulses in which should be able to change the time interval of each pulse
t1 and t3 ( swtiching on intervals ) and also to change the time interval of the switching off interval t2
note: all these time intervals are independet from each others and also not periodic and these three time intervals will be
in µs ( between 1µs and 1,0 µs )
i have Labview version 7.1 and the device which i use is NI PXI- 6259 M series
could you please help me with your advice, how can i produce this signal?
thank you very much
Satriny

[Quickbeam]

Manipulating and concatenating arrays is one way to have two independently variable pulses. To put in error checks for array lengths would be useful.

[satriany]

Hello,
thank you for your effort with your replay but as i tried to change the time to be able to work with µs the output of the array was straight line not pulses
i did this by multiplay µs factor with the the constant of the width. if there is another soultion it will be great

another question which task is suitable to act with the DAQ  as i mentioned before i use the device NI PXI-6259

thank you very much

[devchander]

The trick is to first build a waveform of finite points, then generate it on the analog output of   DAQ card with a suitable update rate, such that the signal generated will have microseconds interval as descriibed below

Your DAQ card has update rate upto 2.8Mega samples/second.

for example, if you have a pulse that stays low for 10 samples and high for next 10 samples( as shown in the example attached by Quick beam) and u update this on one DAQ channe at 2 Mega samples/sec, you will get a cycle pulse of duration 10 Microseconds( 5 micro seconds low, five microseconds high)

Here, 20 samples are updated at the rate of 20 Megasamples/sec to give this output pulse

similiarly choose a suitable number of points to build a pattern you want and generate it a suitable update rate.

hope this helps

Dev

Message Edited by devchander on 04-11-2006 07:10 AM

Message Edited by devchander on 04-11-2006 07:12 AM

[devchander]

To generate on an AO of a DAQ, you will find following examples helpful.

In LabVIEW, Go to find examples>>hardware inpit/output>.DAQmx>>analog generation>> Voltage folder will have all the relevant examples.

[satriany]

Hello,
i think i'm close to finish the function but i have an error in my code i will send the code as an attachement and at the position ( 2a)  in my code there is a big question mark
instead of a task  its name is "get termianl name with device prefix.vi "  and  because of this question mark i couldn't run  the  simulation of the function 
i found on the webside of NI this page http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=DD535427AB1D5A53E034080020E74861&p_...

and after download the file directly the question mark was disappered and i could run the function but
occures an error and here is the message of the error :

 ( error- 200565) occures
 in DAQmx write(Digital 1D U8 1Chan N5amp).vi
 the possible reasons:
 the used ditial channel contains more bits than 8
 bit-version von DAQmx- port writing)

i will apperciate  if you tell me how can i solve this problem 

thank you very much