Write the script in the PLC or HMI

The biggest time and productivity killer for me during projects are :

1. Being OCD with the architecture and tagname structure
2. Deciding where to house alot of my structure text code
3. GRAPHICS!!

Right now I'll just discuss number 2. Example : In the HMI>Recipe Manager Page, I created a dropbox list to select a recipe. On the same page I have a list of 10 different memory tags as my user-defined parameters. Once the save button is pressed, I wrote a script in the Archestra graphic to move all that data to the PLCs "Recipe_1" tags.

I spend a lot of unnecessary time second guessing if I'm doing it the best way possible or trying to decide if I should a dozen similar scripts in the PLC or HMI?

Snap25 said:

The biggest time and productivity killer for me during projects are :

1. Being OCD with the architecture and tagname structure
2. Deciding where to house alot of my structure text code
3. GRAPHICS!!

Right now I'll just discuss number 2. Example : In the HMI>Recipe Manager Page, I created a dropbox list to select a recipe. On the same page I have a list of 10 different memory tags as my user-defined parameters. Once the save button is pressed, I wrote a script in the Archestra graphic to move all that data to the PLCs "Recipe_1" tags.

I spend a lot of unnecessary time second guessing if I'm doing it the best way possible or trying to decide if I should a dozen similar scripts in the PLC or HMI?

Click to expand...

As a general rule, I try to avoid doing any logic in an HMI that could instead be done in the PLC. That said, I'm not obsessive about it when HMI scripting obviously offers the most efficient method to handle things like recipe management. I definitely avoid doing motor control within an HMI, although it is feasible to do so. I've had to work on applications in which HMI toggles directly control solenoids, etc., and that's something that I just wouldn't do.

You haven't really described your problem, you say "Structured Text", but that's a PLC thing not a SCADA thing. You then use an example of recipe interaction from SCADA??

From a script perspective, Are you talking about script organization in SCADA. Should it be all on a 'button' object, or should it call a function and pass parameters from the button?

You can code the PLC to work with the data it has, if the PLC doesn't have access to data (like recipes) then SCADA has to send it to the PLC, there insn't really an option. And no, PLCs shouldn't be a the primary recipe storage area unless a "recipe" consists of 10 setpoints and there aren't many of them.