Post variables

[romer]

Since numeric variables are modal and the post won't output unless prv_var and var are different, if an update is not forced, how can you determine exactly when it is updated using the debugging tools?

(I hope that makes sense).

Also, when a post line uses the statement:

sav_var=var such as in the line

sav_coolant=coolant

what exactly is the post writer trying to accomplish?

Thank you for any help,

Romer

[Reece L Gibson]

I make a dummy output and force it's output at certain post blocks that I 'am working with.

then I can track the time it's output

[Guest CNC Apps Guy 1]

To check a given variable's condition at any given time, you can place a "~" in front of it like "~scoolant", or "~mi7".

[romer]

Thank you for your help guys.

The use of the ~ is something I've read about in the post book but it didn't dawn on me to try.

It told me what I was looking for. I will use that more often in the future. Thanks for pointing that out James.

As to my second question, I have not found anything that references the sav_var that I see used in posts. Can anyone shed some light?

Thanks,

Romer

[Simtech]

Romer,

When programming, from time to time we like to keep in memory the value of certain variables to be able to recall them up later. Here's an example:

If I want to return my machine to it's home position before starting the next operation, like in a toolchange, I would want an output like this:

G00 G90 Z1.0 M05

G91 G28 Z0.0

T01 M06

G00 G90 G54 X1.0 Y1.0 S1000 M03

...

the 'absinc' variable, if used, needs to be saved momentarily so we can recall it's value after the toolchange (we are outputting a G91 for the home position movement), so here it goes:

"%", e

*progno, e

"(PROGRAM NAME - ", progname, ")", e

"(DATE=DD-MM-YY - ", date, " TIME=HH:MM - ", time, ")", e

pbld, n, *smetric, e

pbld, n, *sgcode, *sgplane, "G40", "G49", "G80", *sgabsinc, e

sav_absinc = absinc

if mi1 <= one, #Work coordinate system

[

absinc = one

pfbld, n, sgabsinc, *sg28ref, "Z0.", e

pfbld, n, *sg28ref, "X0.", "Y0.", e

pfbld, n, "G92", *xh, *yh, *zh, e

absinc = sav_absinc

]

pcom_moveb

Taken from the MPFAN post, if you notice the absinc variable was set to 1, absinc = one, so the G91 will output for the reference position. If the initial setting was 0, this value is saved 'sav_absinc = absinc' to be recalled later 'absinc = sav_absinc'.

Hope this helps!

Luc

[mats_asson]

Is it possible to change for example the prv_zabs to something (like -99999) to be sure that it outputs the next time it is used then ?

Mats

[Allan Brown]

Mats - that is indeed the preferred method to force the next occurrence of a variable.

[mats_asson]

Yes...

Great forum this...

I learn something new everyday.

Mats

[romer]

Simtech,

Thank you for your response, that explanation does help.

Dave,

Why would resetting the value to -9999 be preferable to forcing the update using !or*.

romer

[Allan Brown]

Romer - In an Mpfan based post, there aren't a lot of forced variables used. Instead of using flags, counters, or other logic - for instance to catch the first move after a tool change - you can simply leave the variable unforced in plinout and prapidout, but force the output by using a prv_feed = c9k line during the toolchange. Run on sentence. A short one to compensate. Hope this makes sense.

[romer]

Dave,

Thank you, everything makes sense except for

"Run on sentence. A short one to compensate."

I'm a little lost on those comments. Or am I trying to read too much into it?

Romer

[Allan Brown]

One of my sentences was extremely long - something the English teachers used to call a 'run-on sentence'. Instead of changing it, I thought I'd throw in an extremely short sentence. This would in effect lower the average sentence length. Just a joke!

[romer]

I thought I might be trying to find the meaning of something that wasn't there.

Thanks for all the help.

Romer

Some people can read WAR and PEACE and think it a simple adventure story while others can read a Bazooka Joe bubble gum wrapper and unlock the secrets of the universe. - Lex Luther