Help Dual compressor [Logixpro]

[gato]

THANKS.
But what is the function in the program?

 

[Lancie1]

But what is the function in the program?

I do not understand your question. What is the function of WHAT in the program? Do you mean what is the function of each instruction in the list that you posted as used in my previously-posted program?

They are all used as intended and as described. In other words, all those instructions are used to do the job that each was designed to do. None are used differently or illegally.

For example, the first one on your list,(L), is the OTL instruction. This is used on Rung 001 to latch (lock on) a bit called "C1 Has Run". This is a flag bit that simply tells us (and the rest of the program) that Compressor 1 has been turned on at some time in the past. We need this bit of information to decide if we need to switch control to Compressor 2, or not. If Compressor 1 has not run (Bit B3:0/1 is OFF), then we do not switch control. If it is on, then when the pressure switches signal to do so, we switch to Compressor 2. On Rung 003, when Compressor 2 starts, we then unlatch (unlock or unseal) "C1 Has Run" (turn OFF B3:0/1) to signal or flag that Compressor C1 has NOT run in the time since Compressor C2 has run.

 

[gato]

TOD DIV ADD

blocks are needed in the program ??

 

[Lancie1]

Gato,

Now you are starting to think! No, the TOD, DIV, and ADD are only used in the extra Subroutine 3 to calculate the Accumulated Run Time for each compressor, and to display that Run Time on the operator display panel.

Because your instructor's student problem did not ask for the run times to be displayed, you could delete the entire Subroutine 3, or you could study it to figure out how it works.

 

[gato]

can explain step by step the lines

000
001
002
003

PLIS
PLIS
PLIS

THANKS

 

[Lancie1]

These are my opinions only of how the program works. I am not an expert and could be wrong about some of the logic. If you are willing to take a chance on my ideas, then here they are:

Rung 000: When the Start pushbutton is pressed, then the "System RUN" OTE (Output Energize) O:2/2 is turned ON and seals itself ON. When the Stop pushbutton is pressed, then O:2/2 is turned OFF.

Rung 001: When all conditions on the left side of the rung are met, then the Compressor C1 Motor OTE (Output Energize)O:2/0 is turned ON. When it is no longer needed, it is turned OFF. The lampara output O:2/3 is also controlled by the same logic because it should go ON or OFF at the same time as the C1 Compressor Motor. Each time that the C1 Compressor runs, the flag bit B2:0/1 is latched ON.

Rung 002: This rung creates alternator logic that switches (latches or unlatches) the "toggle" relay "C1/C2 TOGGLE" ON or OFF each time it is triggered by the pressure switches and the "One Shot" OSR bit B3:0/10. What causes this alternator to work?

Rung 003: When all conditions on the left side of the rung are met, then the Compressor C2 Motor OTE (Output Energize) O:2/1 is turned ON. When it is no longer needed, C2 is turned OFF. The lampara output O:2/4 is also controlled by the same logic because it should go ON or OFF at the same time as the C2 Compressor Motor. Each time that the C2 Compressor runs, the flag bit B2:0/1 is unlatched to OFF.

 

[gato]

THANKS!