RS logix 500 programming problems

[WrongWay]

Greetings,
Long time listener, first time caller....
I am fairly new to this so bear with me.
My problem(s) are with the use of integers to prompt message displays on a PV600, also program flow is problematic.I have tried ADD and MOV instructions to N7 to ensure part assembly is in correct sequence(Pokayoke, or at least close to it.) As I work through the sequence to test the install, when I make a pick bin sensor(light curtain) the input makes correctly and then all hell breaks loose. When the rung is true I want a value to move to N7, well when on rung 005 of the main program is true N7:0 jumps to a value of 2 instead of 1 and the PV600 message display jumps to the ERROR state.
Here's a copy of the program to anyone that has not only read this far, but cares to venture further.
Thank you

 

[iant]

I cant open your program at the moment
The mov command will be overwritten by the next mov command or not be released if the command is still enabled - program for this -

use a b3: bit in your program that will enable you to toggle on / off while you are testing - you can prevent the program from continuing during your test.

 

[WrongWay]

Thank Ian, I am intending to overwrite the previous MOV to the next integer in sequence, i will look at the potential releasing issue.
Regarding the b3, i think i have seen these called a temp block bit that prevents rungs from scanning?

 

[iant]

sorry for missleading you
B is an auxillary bit or word
b3 is the default (you can create b9 or n9 or other - see manual)
- b3:0 first word - b3:0.0 first bit last bit b3:0.15
- b3:1 etc.

normally use a spare unused bit like b3:0.0 then you can force togle it on or off and it will not change state until you change it back
Also program an always on bit and an always off bit - handy for testing

 

[bayeibrahima]

RS Logix programming

Hello Iant
please what do you mean by "always on bit" and "always off bit"
I also have a basic level.Hope to read you soon.
Best regards

 

[iant]

two bits - you choose
programmed for example

     B3:5/0                      B3:5/1

!-------[/]------------------------(       )--------

    AllWAYS OFF                ALLWAYS ON

NOTE - NO output rung is programmed for B3:5/0

REMEMBER DONT FORCE or TOGGLE THE FIRST BIT ON (B3:5/0)

 

[sthompson]

This is how I generally do it.

Stu....

 

[iant]

nothing wrong with that
It is a shame the AB dosnt have this as standard like other MFG's
The at least have flash (on/off pulse) settings

 

[WrongWay]

Ian,
Thank you I have seen the always on and always off bits in programs I have looked at. The "temp block" I was refering to is used in a similar manner. I appreciate your input so far, in the application I am working with are you suggesting I put this internal bit in on every run and toggle as I scan?

 

[Ron Beaufort]

since you're fortunate enough to be working with RSLogix500, there's probably an easier way to debug your program ...

DISCLAIMER: I haven't had a chance to even glance at the program you posted ...

SUGGESTION: rather than putting your processor in the Run mode, try using the "Test Single" feature instead ... you can click the "Go Single Step" button and make the processor execute just one rung at a time ... watch the red cursor move down through the rungs - and see what happens as the processor goes step-by-step through the program ...

CAUTION: naturally this is NOT something you'd want to try on an active piece of production machinery - but it's an excellent way for beginners to see what's going on in "slow motion" ...

 

[WrongWay]

Thank you Ron, I will definetly use that Monday morn,
By the way sir, you work too much, what are you doing helping out little ol' me on a saturday night.
I was looking at flying out to have you teach me a thing or two last year, something came up with my children during the time I had available. I will do my best to meet you in person someday?

 

[Ron Beaufort]

you work too much, what are you doing helping out little ol' me on a saturday night?

you'd be amazed at how little "work" I do when I'm not actually teaching ... I tell myself that I'm semi-retired ... now if I could just get my wife and the tax man to go along with that idea I'd have it made ...

God has been very good to us ...

 

[iant]

you know it's funny
it is 1:20 pm sunday afternoon here
And I am not getting paid for this either

 

[WrongWay]

To Ian and all those that post to this site,
It is encouraging to see the unselfish interchange that this site offers. I thought about my post last night, realizing that all who respond to posts are to be thanked for the time and insight offered.
Thanks again

 

[iant]

I appreciate the thanks
Dont like to be the pot calling the kettle black though.
Phil Melore has set this site up - I am only back on after some years.
Once I can afford it, I will be donating to the site like Ron who joined after me - Phil deserves the thanks for keeping this site running.