USB 6009 + encoder Lika I41 - how to connect?

[badrequest]

Hi everyone

I'm new to this board and I'm new user of Labview as well. I started to learn it a few weeks ago and I have to solve few problems. I'm not able to come up with everything on my own and that's why I'm asking you. I went through very simple courses of LabView and now I have more serious troubles.

First of all - I have the NI USB-6009 device and an incremental encoder Lika I41-h-500ZCU46L2. It has 8-wire cable and is described here: http://www.lika.pl/pliki_do_pobrania/QR%20I28_I40_I41.pdf . And now - I know the very basics about encoders so the description of the cables is understandable for me. What I don't know is how to connect it to the USB 6009? I need to make a VI which will be counting the impulses and release the camera every X impulses. But I want to start with counting the impulses.

Any help will be MUCH appreciated.

P.

[PBP · Accepted solution]

Hi You can connect 5V supply to Encoder. Connect output A of encoder to PFI0 line of USB6009 and encoder GND to USB6009 GND. Make event counting VI on PFI0.

[badrequest]

Thank you. I've already read that with the USB 6009 card I won't be able to achieve everything from the encoder, because it has only one counter. For example I can't read the direction of motion. BUT if I don't need it, because the encoder will be rotating only in one direction anyway, I guess I still might be able to make my VI, right?

[PBP]

Yes limitation is you can not sense direction. Atleast you can count pulses.

[badrequest]

That should work for me.. I'll try it ASAP and then I'll be asking next questions .

By the way - can I connect the power cable to +5V (number 31) output on the card instead of using the external power supply? The output gives up to 5V and the encoder needs 5V too. Unfortunately I can't find anywhere how much mA it needs.

[PBP]

You can take 200mA MAX from +5V as in manual. You may need pullup resistor. Check PFI0 signal specification in manual. Read manual carefully. 🙂

[badrequest]

Ok, so I found the rest of information. Encoder needs 5V and about 70mA. USB 6009 gives me 5V as well and up to 200mA. NOW my question 🙂 As far as I know when the power supply gives more mA than the device needs nothing should be wrong, sometimes even the power supply will have lower temperature. How about this particular case? Can I safely connect the encoder to my card, or do I need any precautions?

Oh, and the second important question. I am supposed to connect the Ovdc cable to GND input, right? Not the 'shield' wire?

[PBP]

Hi If power supply can meet load demand then there isn't any problem. Just chek PFI0 power specification in manual. It is 2V max you can give to PFI0 line as per specification on page 21.

[badrequest]

Okay, I've connected everything as you said and it works perfectly (thank you!). It looks like this:

- yellow cable (signal A) to PFIO input

- red cable (power supply) to +5V input

- black cable (OVDC) to GND input.

I've put event counting VI and it counts the pulses. Of course it only counts up and it doesn't matter if I rotate the encoder clockwise or anti-clockwise, but it's fine for me and my project.

Now I want to make next step. I need to make a VI which will activate a diode every X impulses for specific amount of time (let's say for Y number of impulses). It will be kind of 'introduction' before I replace the diode with a line camera. Anyway, how should I do that? The first thing I came up with was to use an Event Structure block. Are there any other ways to do this? Maybe any easier ones? Because Event Structure is something I haven't mastered yet and I'm not sure how to programm everything correctly.

[PBP]

Congratulation for your achievement....

You can use two while loop one with Event structure waiting for event to be fired from other loop. second loop will count number of pulses. If it is greater than set count, will generate event using value signaling property node.

Read about event structure.

See my post here and download attached VIs