for all the controllogix xsperts (function block help)

ghriver · Jun 20, 2007

Ok got an easy one. i have a scaled (4-20) signal scaled with the scl block in controllogix. the scaled output (0-100 tank level %) is used in ladder to do a pump up pump down (start pumping when tank level reaches 50% then latch in until tank pumps down to 20%). In ladder this is real easy. How would i do this in function block so i can keep it all together?

danny.michael · Jun 20, 2007

Haven't tested this, but I think it will work....

ghriver · Jun 20, 2007

thx, that will work, i was hoping there was some instruction i was missing to make it less cluttered and easier to trouble shoot. I guess i will stick to the logic to do it. Well maybe not, I use the function block and see if anyone complains.

Thx again.

CroCop · Jun 20, 2007

Do you have V16?
An AOI would do this beautifully............

Gerry · Jun 20, 2007

There are 4 types of flip-flop function blocks. The SETD is equivalent to the and/or combo shown above.

danny.michael · Jun 21, 2007

Thanks Gerry. I'm an old PLC5 guy who has only recently entered the ControlLogix world. The SETD block is a much more elegant solution than my And/Or logic. The ALM block will also work by setting the high alarm limit at 50 and the deadband to 30. But visually, the SETD is the better solution.

This old dog still likes to try new tricks.

ghriver · Jun 21, 2007

yes i have version 16, thx. When i did enter the above it wouldn't compile. The output window refered to a continuous loop. I will try the other mentioned.

danny.michael · Jun 21, 2007

Right click on the output of the BOR block and check "Assume Data Available" and it will compile.

I think Gerry has a better solution.

danny.michael · Jun 21, 2007

Here is the logic for the SETD block:

tvey · Jun 21, 2007

Here's how you could do it using the ALM block:

Attached is the above logic wrapped as an AddOn (remove the .txt extension to import)

-Trevor

rPraveenkum · Jun 22, 2007

danny.michael said:
Here is the logic for the SETD block:

danny

use RESD inplace of SETD for safety conditions you have to stop based on emergency PB & OLR

Here the difference is

RESD

The Reset input has precedence over the Set input.

SETD

Set input has precedence over the Reset input.

for all the controllogix xsperts (function block help)

ghriver

Member

danny.michael

Lifetime Supporting Member

ghriver

Member

CroCop

Member

Gerry

Member

danny.michael

Lifetime Supporting Member

ghriver

Member

danny.michael

Lifetime Supporting Member

danny.michael

Lifetime Supporting Member

tvey

Lifetime Supporting Member

rPraveenkum

Member

Similar Topics