Top 10 Reasons Why I Hate Programming Automation Direct Controllers

[milldrone]

What is "and above a join"

AND above a join =

 

[kamenges]

Originally posted by danw:

That "inverts" the ISA 'standard' (what I learned in an ISA course 25 years ago).

Direct and reverse acting works it way all the way back to the definition of error. Generally when I think of error I think of it in terms of the setpoint. So for me error = setpoint - process variable. However, ISA looks at it the other way. They think of error as process variable - setpoint. So in both cases direct acting is implied when a positive error produces an increasing output. It's just that ISA has a little bit of an odd way of getting a positive error.

My guess is this is done so if you use the derivative on PV controller configuration you don't need to invert the PV derivative before sending it into the CO. But that's just a guess.

Keith

 

[agarb]

OK, thanks, now I know what AND above a JOIN is.

I tried it and at least it throws a compiler error, instead of just not working.

 

[jprindle]

AND above a join =

One nice thing about the PAC 3000 is that it WILL do AND above a join...one of the first things I checked when I got one in...I always wanted that in AD, it makes some code so much shorter

 

[agarb]

I did a search on the PAC 3000 but didn't find any thread discussing it. Is it a brand-new architecture, or did they drag along octal addressing and BCD format for timers and counters?

 

[milldrone]

I did a search on the PAC 3000 but didn't find any thread discussing it. Is it a brand-new architecture, or did they drag along octal addressing and BCD format for timers and counters?

Productivity 3000 is it's proper name. Brand new architecture.

The software is free, download it and give it a test drive.

 

[jprindle]

AND above a join =

Productivity 3000 is it's proper name. Brand new architecture.

The software is free, download it and give it a test drive.

Thanks for correcting this, I was too lazy to type it out when I wrote it.

Everything is new, and it seems like the math is a breeze, you can write out a formula for functions. It is on the front page of AD's website.

There are some things I do not like about it, but it could just be a learning curve for me. I have one and am going to program it to run a couple of closed loop chillers.

 

[bernie_carlton]

We're waiting on high speed counting - then maybe we'll give it a serious look. The software looks interesting. It's certainly expandable.