Test whether two values are equal or not.
Let's say we have a counter that counts the number of cans that passes in front of a photocell. We want to check to counter to see if the counter reaches 24 (full box), then we want to turn the light on to inform the operator that we have a full box ready.
Ladder Logic Solution
- Photocell I:1.0/0
- Light O:2.0/0
When the photocell will go from false to true the counter c5:0 will increment by one.
Check if the counter is equal to 24. If the equation is true then the light will be energized.
- We could have used the C5:0.DN to verify if the counter has reached 24, but we used the EQU for illustration purpose.