Host Engineering Forum

General Category => CTRIO and CTRIO2 => Topic started by: eric14779 on May 02, 2012, 10:57:21 AM

Title: Use of encoder input signals H2-CTRIO
Post by: eric14779 on May 02, 2012, 10:57:21 AM

I have encoder signals

A
A'not'

B
B'not'

Z
Z'not'

the encoder wiring diagram shows using overall shield and twisted pairs for the signal & signal'not'  for each A,B,& Z

the CTRIO wiring shows using only the  A, B, & Z signals with a common.

I had done a encoder project a couple of years ago and I do not remember what i did with the 3 'not' signals at the CTRIO or if i just did not use them.

And if I do not use them should I use shielded wire and not have any twisted pairs or at least keep the A, B, & Z signals in separate pairs.

Thanks,

Title: Re: Use of encoder input signals H2-CTRIO
Post by: b_carlton on May 02, 2012, 11:09:03 AM

Verify that your 'A' etc signals meet the 9-30 VDC requirement for counter inputs. I suspect that they may only be 5 volts.

Title: Re: Use of encoder input signals H2-CTRIO
Post by: eric14779 on May 02, 2012, 12:10:43 PM

b_carlton

you are correct my signals are 5V....  ??? >:(

what do I need to do to boost the voltage....  is there a commercial device available ?

Title: Re: Use of encoder input signals H2-CTRIO
Post by: b_carlton on May 02, 2012, 12:24:42 PM

We have used http://www.bei-industrial-products.com/e_optical-isolator.html (http://www.bei-industrial-products.com/e_optical-isolator.html).
They aren't cheap but they are designed to specifically do this job.

Title: Re: Use of encoder input signals H2-CTRIO
Post by: eric14779 on May 02, 2012, 01:05:49 PM

OK Got one on order...

Now what to do with the differential signals ??

drop them before the isolator or after ??

Title: Re: Use of encoder input signals H2-CTRIO
Post by: b_carlton on May 02, 2012, 01:28:27 PM

The input side takes the differential signals directly. After optoisolation the single-ended signals are generated and sent to the CTRIO. The diagrams are fairly specific. Diagram 1 in the specifications PDF shows exactly your setup. You'll use just the A, B and Z signals of the output on the right side. The 'Nots' on the output will be left unconnected.

Title: Re: Use of encoder input signals H2-CTRIO
Post by: eric14779 on May 02, 2012, 03:06:09 PM

GREAT !!

 Thanks  b-carlton