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DefineVariable in Post Processor
Posted: Tue Oct 04, 2011 10:11 pm
by jnvines
I'm having some difficulty getting DefineVariable to work.
My post processor looks something like this:
DefineVariable("myVar",sc.unitLINEAR,0,10)
function OnInit()
....
//to the end of file
When I save the file it says:
This post has thrown an error:
Lua: Error while running chunk..... global 'DefineVariable' (a nil value)
What am I doing wrong here?
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DefineVariable in Post Processor
Posted: Wed Oct 05, 2011 7:49 am
by Les Newell
You need:
post.DefineVariable("myVar",sc.unitLINEAR,0,10)
Les
On 04/10/11 15:23, jnvines wrote:
[quote]I'm having some difficulty getting DefineVariable to work.
My post processor looks something like this:
DefineVariable("myVar",sc.unitLINEAR,0,10)
function OnInit()
....
//to the end of file
When I save the file it says:
This post has thrown an error:
Lua: Error while running chunk..... global 'DefineVariable' (a nil value)
What am I doing wrong here?
------------------------------------
Re: DefineVariable in Post Processor
Posted: Sun Jan 03, 2021 4:01 pm
by hans
But how to access this variable?
adding somthing like
Code: Select all
circtrans = 360/(diameter*math.pi)
or
Code: Select all
circtrans = 360/(var.diameter*math.pi)
either in function OnInit() or outside a function
gives me the error:
An unexpected error has occurred:
..LinuxCNC_XZA.scpost:43: attempt to perform arithmetic on global 'diameter' (a nil value)
Post processing failed
Re: DefineVariable in Post Processor
Posted: Sun Jan 03, 2021 5:30 pm
by Les Newell
Did you define the variable using post.DefineVariable? For example:
Code: Select all
post.DefineVariable("diameter",sc.unitLINEAR,0,10)
Re: DefineVariable in Post Processor
Posted: Thu Jan 07, 2021 9:42 am
by hans
Les Newell wrote: ↑Sun Jan 03, 2021 5:30 pm
Did you define the variable using post.DefineVariable? For example:
Code: Select all
post.DefineVariable("diameter",sc.unitLINEAR,0,10)
Yes
Re: DefineVariable in Post Processor
Posted: Thu Jan 07, 2021 3:37 pm
by Les Newell
It should work then. Could you send me a copy of your post.
Re: DefineVariable in Post Processor
Posted: Fri Jan 08, 2021 9:50 pm
by hans
Re: DefineVariable in Post Processor
Posted: Sat Jan 09, 2021 11:19 am
by Les Newell
You are running into a sequencing issue. Code ouside of a function is run once when the post is loaded. For instance you have
Code: Select all
post.DefineVariable("diameter", sc.unitLINEAR, 0, 100)
circtrans = 360/(diameter*math.pi)
This defines the 'diameter' variable correctly but then immediately tries to do something with the value, before it has been set. The variable 'diameter' will only become valid after your 'Set post variable' opertion has been executed. Try putting the line
Code: Select all
circtrans = 360/(diameter*math.pi)
in function OnNewOperation(). While you are at it, take out the feed and plunge rate warnings. Your set post variable operation will trigger them.
Re: DefineVariable in Post Processor
Posted: Sat Jan 09, 2021 2:18 pm
by hans
Hmm that gives me nearly the same error message:
Code: Select all
Set variable diameter = 100 mm
An unexpected error has occurred:
...home/hans/.SheetCamTNG-dev/posts/LinuxCNC_XZA.scpost:109: attempt to perform arithmetic on global 'diameter' (a nil value)
Post processing failed
Re: DefineVariable in Post Processor
Posted: Sat Jan 09, 2021 2:51 pm
by Les Newell
Sorry, I didn't think it through fully. OnNewOperation is called before the operation is executed so it checks for diameter just before diameter is set.
Thinking about it, the safest thing to do is put it in OnRapid. It won't try to move until the first operation that uses a tool.
Code: Select all
if diameter then
circtrans = 360/(diameter*math.pi)
else
post.Error("You need to define the diameter!")
end
Re: DefineVariable in Post Processor
Posted: Sat Jan 09, 2021 3:17 pm
by hans
Thanks that's it!