Gray Code and RSLogix 5000

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Sep 2007
Location
Michigan
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Long time RSLogix 500 user here. First time RS Logix 5000 user. I am trying to figure out how to do Gray Code in 5000. I have a 1769-L32E processor with a couple of 1734-AENTs. On one of the 1734-AENT I am using an Omron encoder. I am planning on using a 1734-IB8 input card for the encoder. When using the RSLogix 500 I have used the GCD instruction for this. Does RSLogix 5000 have this type of instruction? If someone could point me in the right direction I would appreciate it. Also has anybody had a situation when the help file won't work on RSLogix 5000?
 
Thanks for the replies. I am going to try the ladder logic mentioned in the Tech Note. Should be putting the power to the machine soon and we will see how successful it is.
 
What web site is supposed to have that tech note?

rockwellautomation.com returns 'no results', and searching for "technote 32743" or "tech note 32743" here on plctalk.net doesn't even find this thread... just "Sorry - no matches. Please try some different terms."

That RSS file won't open in RSLogix Micro Developer.

Here's the code we use for 9-bit 360 degree gray code rotary encoders.

The image is not showing up in Preview, so not sure if the IMG BB code works.
Inserting it with URL too.

https://ibb.co/VLNVG5g


VLNVG5g


(edit1: add attachment)

EncoderLogic.png
 
Last edited:
What web site is supposed to have that tech note?

rockwellautomation.com returns 'no results', and searching for "technote 32743" or "tech note 32743" here on plctalk.net doesn't even find this thread... just "Sorry - no matches. Please try some different terms."

That RSS file won't open in RSLogix Micro Developer.

Here's the code we use for 9-bit 360 degree gray code rotary encoders.

The image is not showing up in Preview, so not sure if the IMG BB code works.
Inserting it with URL too.

https://ibb.co/VLNVG5g


VLNVG5g


(edit1: add attachment)

That would be the Rockwell Knowledgebase. The technote is Techconnect status, which means you need a support contract with rockwell to see it anyway.

And a file not being able to be opened by Micro starter lite means it wasn't made for a processor that is supported by Microstarter lite like the 1000 or 1100.

Are you having issues with doing a conversion in rslogix 500?
 
Thanks for the clarifications. And translation to the new RA format.

That would be the Rockwell Knowledgebase. The technote is Techconnect status, which means you need a support contract with rockwell to see it anyway.

Our support contract expired before I hired in here. I've asked for a Studio 5000 seat, but management doesn't see the need. It will bite them someday, but probably after I'm retired. I do have a rockwell account (15+ character passwords are really not that much more secure than 8, btw).

And a file not being able to be opened by Micro starter lite means it wasn't made for a processor that is supported by Microstarter lite like the 1000 or 1100.

It's a licensed copy of RSLogix Micro Developer, but the support contract is expired so it can't be upgraded to the latest version.

It talks to the 5 different models of MicroLogix controllers we have, no problem - well, except having to unplug the touch screen and use a USB-Serial adapter with a CBL-PM02 on the controllers with no ethernet onboard (they definitely won't spend $500-$1000 for an ethernet I/O card... the machines are 50+ years old, and were integrated to touch screens and controllers, from push buttons and relay logic).

Are you having issues with doing a conversion in rslogix 500

The problem I have currently is the only 1:1 shaft we could access to add the encoder onto is turning the 'wrong' way, so the position sequence goes 0, 359, 358, 357... and rather than engineering the mount to drive the encoder in the other direction, I was hoping to reverse the sequence programmatically more-elegantly than using
N63:1 EQU 359 MOV 1 to N63:2
N63:1 EQU 358 MOV 2 to N63:2
N63:1 EQU 357 MOV 3 to N63:2
N63:1 EQU 356 MOV 4 to N63:2
... 355 more lines (0 is 0 in both directions)

say, using some pre-filled integer files with sequencer and #address arrays (but integer files are limited to 256 elements, for one thing).

It's not a problem with control of functions... we can just use the higher side of the window first with LIM instructions; it's only a matter of displaying the position in the correct sequence on the touchscreen for the machine operator.
 
Long time RSLogix 500 user here. First time RS Logix 5000 user. I am trying to figure out how to do Gray Code in 5000. I have a 1769-L32E processor with a couple of 1734-AENTs. On one of the 1734-AENT I am using an Omron encoder. I am planning on using a 1734-IB8 input card for the encoder. When using the RSLogix 500 I have used the GCD instruction for this. Does RSLogix 5000 have this type of instruction? If someone could point me in the right direction I would appreciate it. Also has anybody had a situation when the help file won't work on RSLogix 5000?

What is the part # of the Omron encoder?
I assume this is the same encoder you used in the SLC500. If so, what type of the 1747 input card were used to connect to the encoder?
It would be interesting to see how a 1734-IB8 would work.
Btw, I noticed you attempted to convert RS5000 back in 2007. lol.

In a nutshell:
Code:
Binary to Gray Code Conversions: 
GRAY_DST.[x] = BIN_SRC.[x] XOR BIN_SRC.[x-1]

Gray Code to Binary Conversions:
BIN_DST.[x] = BIN_DST.[x+1] XOR GRAY_SRC.[x]

P.S. I just noticed a different guy were asking the question now. lol
 
Last edited:
If you need to leave an indication of 0 at the same rotation point then test for 0 and if so transfer that to the result else subtract the indication from 360 and store the result.
 

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