1756-HSC Application Example

[mhi 2]

Hello,

I have a cut to length application, and i want to use Contrologix V21.11
CPU 1756-L71 together with 1756-HSC/B counter module to make this
application.

There will be a measuring wheels place directly above the material to detect the length of material pass thru 
and also the line speed.
The measuring wheels is driving a encoder over a gear ratio of 20/6 to increase the encoder pulses.
That mean, 6 turns at measuring wheels will give us 20 turns at the encoder.

The encoder is having a 16384pulses/rev. In quad mode, we will have 65536pulses/rev from the encoder.

The measuring wheels diameter is 200mm, which mean circumference will be 628.3185mm.
That means, 628.3185mm=21854.3333 pulses (Result of 65536pulses x 20/6).

Counter 0 of 1756-HSC will be configure to Encoder x 4 to measure the material length. Roll Over=16123456.
Max measurable encoder revolutions=16123456/21854.333=737 revolutions. 737 revolutions at encoder mean 737x6/20=221 revolutions at measuring wheels. 221x628.3185mm=139066mm or 139.066m.

Counter 1 of 1756-HSC will be configure to Freq Mode to measure the material speed.

As the material flow continuously, the counter will roll over to 0 at every 139.066m.

How can i have the Output 0 of the 1756-HSC to turn ON for 100ms only when the length reached 4920mm, and at the same time, Output 1 turn ON for 100ms only when length reached 5000mm.

Mean output 0 will turn a precisely (tolerance of 1.5mm allow) at 4920mm,9840mm, 14760mm, 19680mm........132840mm,137760mm..(142680mm is not possible, counter 0 already Roll over to zero)...

And output 1 will turn a precisely (tolerance of 1.5mm allow) at 5000mm,10000mm, 15000mm, 20000mm........130000mm,135000mm..(140000mm is not possible, counter 0 already Roll over to zero)...

How to solve this application with Contrologix ? 

Any programming example and advice is very much appreciated.

[AndrewG 13]

Not sure if this will help but Rockwell has some sample code that uses the 1756-HSC here:

http://search.rockwellautomation.com/search?client=samplecode&oe=UTF-8&ie=UTF-8&output=xml_no_dtd&proxystylesheet=samplecode&site=sample_code&getfields=*&lang=en&hl=en&sort=date:D:L:d1&wc=200&wc_mc=1&ud=1&filter=0&q=+1756-hsc&dnavs=+1756-hsc

(It is Filename/ID 72311 in the Sample Code Library)