GX developer: What does this message mean?

[Mas01]

When I press F4 to convert the code, I get this message.
What does it mean? Thanks

 

[PLCDontUQuitOnMe]

Been a few years since I've used Mitz, but I remember seeing this every time I would make an online edit. I think it is memory allocated for online edits. I seem to remember there was somewhere where you could increase this number from 500 to a higher value. I also remember that as I would make more and more edits, the available "steps" would decrease, and I think when they got to zero, it would just ask if I wanted to increase it and I would say yes and carry on.



So basically it was never a problem as far as I could remember and never stopped me from doing what I had to do. I'm sure someone here will chime in with a more in-depth answer.

 

[Mas01]

Been a few years since I've used Mitz, but I remember seeing this every time I would make an online edit. I think it is memory allocated for online edits. I seem to remember there was somewhere where you could increase this number from 500 to a higher value. I also remember that as I would make more and more edits, the available "steps" would decrease, and I think when they got to zero, it would just ask if I wanted to increase it and I would say yes and carry on.



So basically it was never a problem as far as I could remember and never stopped me from doing what I had to do. I'm sure someone here will chime in with a more in-depth answer.

Cheers for the reply.
I also noticed that the number decreases with each edit I make. Was getting a bit worried I might be running out of memory or something if I reached the limited.. Don't think I'll worry about it too much. Cheers

 

[parky]

I have never had it go to zero, I believe it puts NOP's in places to allow an on-line change so if there are too many NOP's or the code you are changing will shift the code by more than the number of steps set in the compiler it will become a problem, the way round it is to compile & download the complete code, this will reset it back to the default 500 steps.
Some things you cannot do on-line download for example if you modify a function block (only valid in FBD/LAD) or you have a jump to a subroutine & the code moves the pointer too far then again the only option is to compile & download in stop mode.

 

[Mas01]

I have never had it go to zero, I believe it puts NOP's in places to allow an on-line change so if there are too many NOP's or the code you are changing will shift the code by more than the number of steps set in the compiler it will become a problem, the way round it is to compile & download the complete code, this will reset it back to the default 500 steps.
Some things you cannot do on-line download for example if you modify a function block (only valid in FBD/LAD) or you have a jump to a subroutine & the code moves the pointer too far then again the only option is to compile & download in stop mode.

Thanks for the reply, parky.
What's a NOP?

 

[I_Automation]

NOP means No-Operation


Basically a NULL command used as a placeholder for an empty rung, and what I call a FYI rung - N.O.'s and compares at the beginning just to show the status of the bit or word when monitoring online

 

[Mas01]

NOP means No-Operation


Basically a NULL command used as a placeholder for an empty rung, and what I call a FYI rung - N.O.'s and compares at the beginning just to show the status of the bit or word when monitoring online

Thanks for the answer.

 

[parky]

Sometimes a small change like removing a contact in a rung the download (well compile & download will put in a NOP (no operation) rather than shift up the whole program for example if you have a program that is 2000 instructions long but you delete an instruction in a rung at about 600 then rather than reduce the whole program (shift up) from 600 to 2000 it will only shift up the one ladder then insert a NOP, so the program is still 2000 instructions long.

 

[Mas01]

Sometimes a small change like removing a contact in a rung the download (well compile & download will put in a NOP (no operation) rather than shift up the whole program for example if you have a program that is 2000 instructions long but you delete an instruction in a rung at about 600 then rather than reduce the whole program (shift up) from 600 to 2000 it will only shift up the one ladder then insert a NOP, so the program is still 2000 instructions long.

Thanks for this, much appreciated .

 

[Mas01]

On a related subject, I've never understood the rung numbering on GX developer. Is the number of a particular rung related to the previous rung number plus the number of contacts etc in the previous rung?

 

[parky]

Yes, the difference is the number of instructions and their own count so for example simple instructions like AND OR etc. each one will be a one instruction, however, a maths instruction could be 2 or more instructions (depends on how that instruction is used) that is why you will see rungs that have say 5 steps but only 3 instructions so for that rung let's say it is AND xx AND xx ADD D0 D1 D2
that rung starts at 0 the next rung starts at 5.
So it's not exactly the number of physical instructions but the combined instructions of all where some may have three or more parameters

 

[Mas01]

Brilliant, thanks again.