Using the FP-PG-522 through Labview

[Brian Chan 1]

I am trying to use the Pulse Generator FP-PG-522 through Labview.

I have followed the instructions on the example VI (Pulse Generation.vi),
but still cannot seem to generate pulses. The FP 1000 shows access when I run the VI, but the
pulse channel indicator does not light up, and no pulses show on an oscilloscope
either. However, the VI runs without errors.

Following the instructions on the VI, I have created these extra items in MAX:

Discrete inputs, Output 0:
-Control @Ch0
-Generate Pulses @Ch0

Count inputs, Pulses Remaining 0:
-Off Time @Pulses Remaining 0
-On Time @Pulses Remaining 0
-Pulse Mode @Pulses Remaining 0
-Resolution @Pulses Remaining 0

Is there anything that I seem to be doing wrong or neglecting?

Thank you,
Brian Chan

[George M.]

Hi,

There is an online Knowledge Base that will help you to understand why the channel light is not turning on.

Also, here is a link to another thread that talks about setting this module up:

http://forums.ni.com/ni/board/message?board.id=110&message.id=599&requireLogin=False

This should get you going. If you still have questions, please let me know. Thanks, and have a Great Day!

Best Regards,

George

[Brian Chan 1]

Hi George,

Thanks for the link, I think I see what my problem has been-

I am using Measurement & Automation Explorer, and have looked at the NIOSH.iak file downloadable from your link;
Under the Data Neighborhood, Fieldpoint Items, Pulse Generator,

I need to create Items of Type: "Channel Attribute" and Type: "Channel Command" but when I create a new item, MAX only allows me to make them "Discrete input" or "Count input"

Hence, I'm not quite there yet with getting things to work. This time I've searched the Discussion Forums and haven't found anything describing this problem.

Brian

[George M.]

Hi,

You can access the Channel Attributes and Channel Commands in MAX. You can get to these by first selecting the module under remote systems. Once you have selected the module, there will be two tabs available at the bottom: Device Configuration and Channel Configuration. You want to select the Channel Configuration tab. In this, you will be able to define the Channel Attributes and Channel Commands.

I hope this helps. Have a Great Day!

George

[Brian Chan 1]

Hi George,
Thank you for your help, we were able to get the module generating pulses, finally.

I have a few more questions to whom it may concern, regarding the PG-522 and hooking it up-
(these questions may reflect more on our lack of electrical engineering knowledge; we're all mechanical engineers)

We are generating pulses with Channel 0 of the Fieldpoint Module FP-PG-522. A lab power supply supplies 5v to the V and C terminals. The manual for the FP-PG-522 suggests connecting a load between the Vsup and Vout. The pulses that come out, as measured by an oscilloscope connected between the Vsup and Vout, span from 0 volts (off) to negative 5 volts (on). However, when we use the oscilloscope to measure voltage between Vout and Com, we do not measure a signal of 0 to +5 volts; instead we measure pulses that are much smaller. We have also tried connecting Vsup to the "+" terminal of the oscilloscope and the Vout to the "-" terminal. The signal came out 0 to +5V as we wanted, but there was a large 5v "hump' added to the signal, which was undesirable (and inexplicable). We would like a signal that spans between 0-5 v as we are using another Fieldpoint module that outputs a 0-5v signal (the FP-DO-401), and is to share a common ground with the FP-PG-522. A smaller problem is that the pulses generated by the FP-PG-522 are not clean square-wave like outputs, but have a very noticeable die-off curve after each "on" phase, and we would like to make the pulses more discrete if possible.

Why is the Pulse Generator channel designed as a 'sinking output'?

[sergesl]

Hello Brian,

When you view your signal on the scope (when you were getting -5V), you probably had the positive lead of the scope connected to Vout and the negative to Vsup wich explains why you had -5V. If you just reverse the leads when measuring on the scope so that negative (black) goes to Vout and the other goes to Vsup, you will get the waveform you are looking for.
The sinking output circuitry you see on the diagram means that it is an output that takes current coming in. When current flows through the load, it goes from Vsup through the load into the Sinking Output Circuitry on Vout connector, meaning that Vout takes current coming in and is therefore a sinking output.
Hope this helps...

SergesL

[emcuebe]

Where can I get a copy of this Pulse Generation.vi?