View Full Version : Temp probe/Heater Issue with Apex

12/15/2012, 09:45 PM
Hey guys this is my code for my heater.

Fallback OFF
If Tmpx2 < 78.0 Then ON
If Tmpx2 > 78.7 Then OFF

The issue I'm currently having is my Heater turns off at exactly 78 degrees, and it does not shut off at 78.7? the one main reason is because i see my graph and it always says 77.9/78/77.9/78. i fear that this might cause an issue with my heater. any ideas?

12/15/2012, 10:37 PM
Remove the Set OFF, it interferes with the lower bound.


12/15/2012, 10:52 PM
Yep, what he said...

12/15/2012, 11:15 PM
will try this! thanks for your input

12/16/2012, 12:37 AM
works flawlessly ! thank you guys, still confused about the SET statement and if i should even use it for anything else except for pumps

12/16/2012, 03:05 PM
The purpose of the SET statement is to establish a starting point for the rest of your program statements. Not all program statements need a SET and sometimes you don't even want one. It's entirely optional and again, its sole purpose is to provide a known starting point for your outlet state.

12/16/2012, 04:51 PM
There a few key things to understand when working through Apex code. First, a FALSE statement is ignored. Second, is that the last TRUE command is what determines the resultant state of the outlet.

The Set command is always TRUE. If the Temp is less than 78, then the first Temp condition will be TRUE and the outlet will turn ON. However, once the Temp reaches 78, both Temp conditions will be FALSE. Therefore, the last TRUE statement is the SET OFF command.