Test whether one value is not equal to a second value.
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 green light on, but if the count is not equal to 24 then we want turn the read light on.
Ladder Logic Solution
- Photocell I:1.0/0
- Light Green O:2.0/2
- Light Red O:2.0/3
When the photocell will go from false to true, the counter will increment by one.
We will verify if C5:0.Acc = 24 equation is true. If it is then we will energize the light full.
We will verify if C5:0.acc <> 24 equation is true. If it is true then we will energize the red light.
- The red light will basically be on except when the count is equal to 24.