I'm not sure if you guys still remember this project template, I'm reading it. If you can't remember, it's here (Thanks RMA).
Q1:
I noticed in each FB, it either use "STAT" or "IN_OUT" local memory instead of use one shared DB (such as 'Station'). Because it doesn't have a DB, so everytime when it's return to calling block, all the memory will be replaced by another current running block, how can you keep data consistency?
For example:
First you call "FB Load Inputs", it has its local symbols declared in 'STAT' as "Station";
Then you call "FB Setpoint Evaluation", it has its local symbols decalred in 'IN_OUT' as "Station" as well.
So how the values pass by thru "FB Load Inputs" to "FB Setpoint Evaluation" ? S7 supose to clear the memory before it load "FB Setpoint Evaluation".
Q2:
Why in some FB the symbols declared in 'STAT' and others in 'IN_OUT'? What's the reason to put it in 'STAT'?
Q3:
For the FBs which symbols declared in 'IN_OUT', it's same as FC. Why use FB not FC?
Q4:
Let's back to Q1. What I'm doing is almost same except declare all the symbols in some shared DBs (because I have a lot, I tried to put in one DB, and it's too slow to open it and display symbol names while LAD editing). What's the difference of that two ways?
Q5:
You opened a DB as an IDB, what's for? If I do it in LAD way, how can I do that or I don't need to worry about that at all? Or if I involve LAD at least at the beginning, do I have to use STL to open this DB as IDB ?
Thanks
Q1:
I noticed in each FB, it either use "STAT" or "IN_OUT" local memory instead of use one shared DB (such as 'Station'). Because it doesn't have a DB, so everytime when it's return to calling block, all the memory will be replaced by another current running block, how can you keep data consistency?
For example:
First you call "FB Load Inputs", it has its local symbols declared in 'STAT' as "Station";
Then you call "FB Setpoint Evaluation", it has its local symbols decalred in 'IN_OUT' as "Station" as well.
So how the values pass by thru "FB Load Inputs" to "FB Setpoint Evaluation" ? S7 supose to clear the memory before it load "FB Setpoint Evaluation".
Q2:
Why in some FB the symbols declared in 'STAT' and others in 'IN_OUT'? What's the reason to put it in 'STAT'?
Q3:
For the FBs which symbols declared in 'IN_OUT', it's same as FC. Why use FB not FC?
Q4:
Let's back to Q1. What I'm doing is almost same except declare all the symbols in some shared DBs (because I have a lot, I tried to put in one DB, and it's too slow to open it and display symbol names while LAD editing). What's the difference of that two ways?
Q5:
You opened a DB as an IDB, what's for? If I do it in LAD way, how can I do that or I don't need to worry about that at all? Or if I involve LAD at least at the beginning, do I have to use STL to open this DB as IDB ?
Thanks