Re : wait a time depending of number acquisition

[Mibemol]

Hello,

I use labview 7.1 and 8.20 with 6251 daq Board.

For numeric acquisition

Port0 and 2 entries

line port1.5 out

(How to send a low level after every acquisition ?)

I want to send after every aquisition done by a numeric acquisition (port0 and port 2) trigged by a front one pulse low level (1ms).  After every acquisition a level down must be sent on a line E/S always high level, for exemple : port1.1 become during 1mS level down and return to high level. After this, the next acquisition occure and a next level down is sent.

But there is times (low level port1.5) must stay 10 S low level not only 1 mS i.e if n aquisition equal to 16, 32, 64,128,256,512,1024 the low level stay 0 during 10 s.

Actually, I nead to fix time of the level down depending of the number of data acquired.

Is anybody able to help me !

Thank you for help

Best regards

[Omar S.]

Hello,

I'm afraid to don't understand all your specifications, can you explain your problem in a simmple way.

A picture of your signals will be better.

Regards.

Omar. NIF

[Mibemol]

Thank you Omar,

I'm sorry for my bad explanation, I asked for too many things in the same message.

So, once again, sorry !

I would like to acquire 16 bits of a data. This acquisition must start on an external numeric front. It seem to be impossible to do it with a 6251 serie M card.

Because I have 3 ports, but only one can be cadenced (I think). So is it possible to acquire 2 ports and use an other mean to cadence the acquisition on the front clock. 

I think there is no way to do this, and an other card (with 2 ports cadenced) must be bought.

Thank you for your help !

Best regards

Mibemol (Hadj)

[Omar S.]

Hi,

It is not possible to achieve this type of application with this board, have you got another board available?

Let me know in order to check if the application can matched with your hardware.

Regards.

[Mibemol]

Hello Omar,

Yes, I have one which can be used  whith the 6251: the 6229 NI card.

Thank you Omar for your help.

Best regards

Mibemol  ( Hadj )

[Omar S.]

Hi Mibemol,

With your boards, it is possible to achieve digital triggering.

Have a look on the following document:

http://digital.ni.com/public.nsf/websearch/E761255A5729CD2E862570310075A23A?OpenDocument

Thanks to a digital triggering, you can use an external signal to start your acquisition.

Have a look on the following document in order to know how implement a start trigger with DAQmx functions:

http://zone.ni.com/devzone/cda/tut/p/id/4329

Regards.

[Mibemol]

Thanks,

Have a nice day

Best regards,

Mibemol