Ao write and Ao start

[JCC_(SK)]

Hi Hood,
my problem is I don't have any DAQ card. And I can not testing your problem.
Please try look this few examples:
This is what you wont:
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3D83756A4E034080020E74861&p_node=201241&p_source=external

Two paralel generators:
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3E15B56A4E034080020E74861&p_node=201244&p_source=external

Look example on: http://zone.ni.com/devzone/devzone.nsf/webcategories/BF1AC4565B4D356486256797004CBD45

Continuously Generator:
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B123AE0CBAC1111EE034080020E74861&p_node=201241&p_source=external

Theory:
http://zone.ni.com/devzone/conceptd.nsf/webmain/1239BF7126B432D786256802007B90C6

If you look to ther exampel, you can see different order of AO VIs as in your VI. NI use in while loop only "AO_Write.vi". And not your triple combination "Write-Start-Wait".
I hope that help to you.

If you have NI-DAQ wizard try with this generate new "icon" for analog output wiht sine-wave {I can not test it, I saw it only in demo. It is possible that working.}

Answers:

Points 1) and 2) probable handle by examples.

Point 3) hmmm It is possible you wrong set up you card. Ther Exampes from IN working well? They have Parameter set to 0. Do noy have programing documentation to your card? ;-(

Point 4) Between examples is one parallel � dual chanel generator VI �AO 6_10.vi�

Point 5) and 6): Be careful when you wont use two and more wave (generated to one array). Everyone must have same numbers of samples and must by continual betweend perionds. Example: You have signal no. 1: Freq = 10 Hz and 1000 samlpes per second. From this you know you have 100 samples per one period of signal no.1.
When you have signal no.2: Freq = 20 Hz, sample per second you must have same as in signal no.1 that are 1000. And you know you have 50 samples per one period of signal no.2.

But what happened when your signal no.2 will be have frequenci 33 Hz? You have big problem, and your signal no.2 will be not sine signal ;-( Because you need 30,3030� samples for one period.

When you have still problem with AO start.vi {you can not pause � breake runing} try contat NI distribution in your country. If is it bug or feature. It is Their job to help you.

Have a nice day

JCC

[hood1]

Thanks JCC for detailed reply.
few issues in response of your reply that i would like to raise.

1)regarding point 6, let us first talk about only one source with amplitude 5(positive peak) , -7 (negative peak) and Frequency of 1.6Hz. in your example that you posted to me. i give 20000 periods and then i switch on stop watch to calculate the total time. the total time of the execution must be
12500 seconds.that means clearly when i run this VI.these 20,000 periods must take 12500 seconds to finish the execution. if i make pause in between and resume. it must pause and resume from the moment.that means the rest time and number of remaining periods must finish in the rest time. this tota
l time i calculated on the basis of frequency and and total number of periods.i am using the following formula(see attached VI please). now my question is that these numbers(20,000 in my case) of periods are not finishing their execution in corresponding time. why? am i using the wrong formula for frequency time conversion or some other reason. i hope i explain my question now.
2) regarding Ao start it is mentioned in the AO start help, when you set 0,it will continuosly generate the sine wave and when you set this parameter to 1, it will execute only once.that means by setting this parameter, you cannot interrupt it any more and when you set the parameter to 1 you can pause and resume. this is that i understand by setting parameter 0 or 1.
i am testing other examples that you send to me. as soon finish it i will acknowledge to you.
any way many thanks for your asisstance.
regards