Two frequency with two square signals on daqcard conuters synchronized with analog inputs

[Yvan]

Hello,

My configuration : PC portable P4 / 1.8GHz, Win 2000, Labview 7.0, DAQCard AI-16E-4, BNC 2110 and two magnetic speed sensors (6000rpm, 120 top/rotary)

1) I would like to recorde the two frequencies with the two counters of the DAQCard. Can I do it with my configuration and how ?

2) Can I synchronize these two inputs with analog inputs ? If not, which configuration I need for ?

Thanks a lot,

Yvan

[daviddelebecque]

Bonjour Yvan,

Pour répondre à vos questions...

1) I would like to recorde the two frequencies with the two counters of the DAQCard. Can I do it with my configuration and how ?

Votre carte possède deux compteurs qui vous permettront de faire deux calculs de fréquence. Je vous conseille de consulter l'exemple qui se trouve dans LabVIEW 7.0 Aide/recherche d'exemples. Naviguez dans le répertoire E/S matériel/Ni-DAQ traditionnel/compteurs/DAQ-STC/Measure Frequency.vi. Concernant la connectique de votre signal, elle est expliquée dans les propriétés de ce VI, dans Documentation. (Connect the gating signal to the gate input of the gating counter).

2) Can I synchronize these two inputs with analog inputs ? If not, which configuration I need for ?

Vous pouvez effectivement utiliser les signaux TTL comme horloge d'échantillonnage pour acquérir des entrées analogiques. Vous trouverez un exemple dans E/S matériel/Ni DAQ traditionnel/Entrée analogique/général/Cont Acq&graph ExtScanClock.vi. L'horloge externe se configure dans le VI AI-Démarrer.

En espérant que ceci vous aide à solutionner votre problématique.

Cordialement,

David DELEBECQUE

Ingénieur d'Applications

NI France

[devchander]

Hi David,

A small request,

could you plz post your answer in English too?

Thanks in advance.

Dev

[daviddelebecque]

Sorry from english-speaking people...

1) I would like to recorde the two frequencies with the two counters of the DAQCard. Can I do it with my configuration and how ?

Your board has 2 counter inputs (with 2 gates) which allow you to measure 2 signal frequencies. Take a look at the example located in LabVIEW 7.0 in Help/Find Examples. Navigate in the folder I/O material/Ni-DAQ traditionall/counters/DAQ-STC/Measure Frequency.vi. For I/O connexions of your signal, go to VI properties, in the Documentation. (Connect the gating signal to the gate input of the gating counter).

2) Can I synchronize these two inputs with analog inputs ? If not, which configuration I need for ?

You can use TTL signals as external scan clock to acquire analog inputs. Look at the example I/O material/Ni DAQ traditional/Analog input/general/Cont Acq&graph ExtScanClock.vi. The scan clock is configured with the AI-Start.vi.

Hope it helps you,

Regards

David DELEBECQUE

Ingénieur d'Applications

NI France

[devchander]

Hey David,

merci beaucoup!

that's the limit of my french! 😉

regards

Dev

[daviddelebecque]

It is not so bad...

De rien,

Good luck !

[Yvan]

Thank You. After careful thought, I have come to the following conclusion.

The example "Measure Frequency.vi" is for one input (two counters in cascade) and it calculates the average frequency of 100ms of acquisition.

I need a continious synchronized acquisition at 500Hz of the two frequncies (two magnetic speed sensors) an analog signals.

I could have two DaqCard AI-16E-4. Does it possible now ?

Regards

[daviddelebecque]

Hi,

Obviously, the example I told you to look at is to measure one signal frequency. You can copy/paste the code to run it on 2 counter inputs to measure 2 signal frequencies.

Only one board is sufficient for that kind of operation.

Regards

David D.

[daviddelebecque]

Bonjour,

Je vous joins cet exemple qui opère la mesure de fréquence sur les deux compteurs... Je vous laisse le découvrir.

Cordialement,

David D.

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3E8E556A4E034080020E74861&p_...

[Yvan]

If someone seach Gate and Source on BNC 2110, it doesn't appeared ! Then you have to watch "Multifonction DAQ Cable and Accessory Selection Guides" :

E Series sauf 6025E
Broches : ***
40 : CTR 1 OUT
42 : PFI3 / GPCTR1_SOURCE
41 : PFI4 / GPCTR1_GATE
02 : CTR 0 OUT
37 : PFI8 / GPCTR0_SOURCE
03 : PFI9 / GPCTR0_GATE

Regards