Setting up Streaming Mode for Quadrature Encoder

[dark212]

Hi there!

I want to read a quadrature encoder using streaming mode with my U3-HV.

Basic Command/Response mode worked fine, but I now require a higher sampling rate.

Before, I just needed to enable two timers in a 'StartUp' sequence, specify the QUAD mode and read from a single 'Timer' channel.

But I can't seem to figure out how to set up streaming mode for this application.

I tried creating channels 200, 224, 201, 225, but I'm not sure how to get the single absolute position of the encoder.

All help will be appreciated!

Thanks in advance!

Alvin.

[LabJackSupport]

First, you still need to enable/configure the timers. You can do that with a startup sequence like before, or use the "config defaults" section of LJControlPanel.

Then you want to stream channels 200 (LSW) and 224 (MSW). To get the total count take Ch200+(Ch224*65536).

http://labjack.com/support/u3/users-guide/3.2.1

Everything in stream mode is considered an analog input channel, so in DF you want to use iotype A/D. I would start with the example U3_StreamTimerCounter.ctl:

http://labjack.com/support/ud/examples/daqfactory

[dark212]

Thanks for the reply!

I can get the counts to increment nicely, however, if I go the other way past 0 counts, it goes straight to 2^32. Is it possible to make it go negative like it did in basic command/response mode?

And also, since there isn't one single channel that displays the total counts of the encoder, how can I implement logging of this data? There are other input channels I would like to stream and log, so preferably without creating a sequence to continuously calculate the total counts, store it in a variable, and export.

Thanks in advance!

Alvin.