MAX program quirky?

[walter-donovan]

Sorry if this forum's wrong. Tried digital I/O but no response & I can't find a forum for MAX.

I have a problem with a client computer that houses PCI-6071e & PCI-6043. In MAX test panels.

I have quad encoder lines hooked to PFI0 & PFI1. If I go into counters, set for edge count, trigger = PFI0 (or PFI1) I get counting when I turn the encoder. But if I go into digital I/O I get no response from the encoder. All 8 lights stay on.

Tried this on another machine (with USB-6211) it works fine.

MAX or drivers are broken right? Not possible to have counters good and signals across all PFI's bad, right? 

[smercurio_fc]

other post is here

You need to be patient. The forums are not a good venue for "instantaneous" responses. Most of the people on here are volunteers (like myself) who have full-time jobs. If you need immediate assistance then you should contant NI Tech Support directly. 

[walter-donovan]

Sorry. I wasn't looking for immediate responses. The post had been up for 4 days with no responses other than a series of questions that I answered. I had no way of knowing if my post was in the correct place since it didn't clearly fit into any board here.

Are you familiar with the way MAX operates? Is the behavior I describe flawed? If I can get an answer to this basic question, I can proceed.

Message Edited by walter-donovan on 02-09-2009 12:53 PM

[smercurio_fc]

I hadn't seen the original date of the post. I had seen the dates on the latest posts, so it seemed as if there was a disappointment in the lack of immediate response. Sorry about that.

To your question: Have you verified that if you stick in a voltage (not the encoder output, but some other voltage source), or ground one of the digital I/O lines, then the line state changes?

[walter-donovan]

No. And simply because it works correctly as a counter. It just doesn't work correctly as a basic input. My assessment was that the bug could not possibly be with the sensor but has to be with software. I am trying to verify this concept before proceeding.

Addendum:

I just ran test panels with the encoder removed from the circuit and get same reading (all high signals). This can't be right.

Message Edited by walter-donovan on 02-09-2009 01:22 PM

[mishkin · Accepted solution]

walter-donovan,

I believe you misquoted your second DAQ device model number - I don't believe we make a 6043. 

If you want to use an E series card (6071E) with a quad encoder, you'll have to hook it up a little differently. Most quadrature encoders have at least two pulse output signals (and maybe a third which is the index output). These two pulse outputs, A and B, should be wired into the DAQ counter source input (PFI3 for Ctr 1or PFI8 for Ctr 0) and the P0.6 input respectively. Then I recommend setting up a quick edge counting task in MAX to verify that this setup works (use "externally controlled" for direction). 

The reason it worked a litte differently with your other card (USB-6211, M series) may be that the counters of the two cards are different. M Series supports NI-TIO counter features, such as two-edge separation and quadrature encoding, and E series does not (for other differences, see this article). However, you can still use your E series board with a quad encoder like I described. For more information, 

Using Quadrature Encoders with E Series DAQ Boards

I do not think anything is wrong with MAX or your drivers. The lights may or may not reflect the signal on your digital inputs depending on the speed of the pulse train coming in from your encoder. 

Message Edited by mishkin on 02-10-2009 12:30 PM

[F._Schubert]

Just some basic trouble-shooting:

Do you have the task running (green error) on digital I/O when you move the encoder?

As sidenote: PFI is a complete different circuity than DI. They only share the screw terminal. DI allows to aquire waveforms, PFI feeds the signal into a counter.

Felix