time taken to recieved an analogue input

[ash.]

Hi there,
I am trying to synchronise the time at which an analogue input is recieved with other data i am acquiring. Thus I wish to know exactly when i start recieving my analogue acquisition in relation to the other data i am acquiring. The other data i am acquiring is high speed film that is triggered by a delayed pulse. The delayed pulse function is located in a sequence frame prior to the analogue acquisition function.

I have found that when acquiring multipoint analogue data, there is a small delay in this aquisition. I want to know if this small delay is occuring before or after the acquistition takes place. that is, is there some kind of initialisation delay taking place before the analogue input is reciev
ed? Or is there some kind of processing delay after the analogue acquisition?

Please have a look at the example code and accompanying text for a clearer question.

cheers,

ash.

[waldemar.hersacher]

Hi Ash,

most of the delay occurs before acquiring data to initialize the card.

Since you have a trigger you should use the intermediate Analog In VIs. There you can configure your card to use a trigger signal. So you can synchronise your high speed film and your DAQ Card by the hardware pulse. A good way to start is the LabVIEW measurement manual Chp. 6>>Bufferd Waveform acquisition>>Simple buffered analog input examples.

[ash.]

Thanks very much for the prompt answer Waldemar.

Thanks also for the advice. Unfortunately my programming knowledge is fairly primitive and I don't really know how to use the intermediate functions (I did earlier have a go at using the triggering examples). Alas, I don't really have any more time to spend on improving the program thus the existing program will have to do, warts 'n all.
Cheers,
Ash.

[ash.]

Hello all,

just furthering the question, I was wondering if a value is known for the delay in initialising the card. Or does it depend upon the processing speed of the computer.

Alternatively, if this value for the delay is not possible to evaluate, how can I use the delayed pulse function to trigger an analogue acquisition? Keeping in mind that the value of the pulse delay and pulse width is used actuate a solenoid for an exact amount of time. In other words, can the delayed pulse function be used to both send a pulse to a piece of equipment and to trigger an analogue acquisition?

Please have a look at the acompanying code,
cheers,

Ash.