Trailing edge timer

I need to trigger a process off the trailing edge of an item passing in front of an eye.

Could someone offer some quick simple logic that will trigger a bit when a photo eye transitions from true to false and then resets for the next item to pass.

I've used trailing edge timers before but for some reason today the logic escapes me.

Use the eyes TRUE/ON to self latch a bit...this will state it WAS ON. In the next rung put that WAS bit in series with the eyes -|/|- (normally closed contact) to trigger the process. You can unlatch the WAS bit with the process bit.

CONDITION    SETUP       OS

---| |--------|/|--------( )---



== Controlled logic using OS goes here ==



CONDITION              SETUP

---| |------------------( )---

When CONDITION (PE 'sees' again) goes true, OS is on for one scan

Thanks guys! Your solution stopped that nasty self repeating loop I was in. My process is up and running great.

I noticed that in another post you mentioned the D0-06. That model has two contacts called Positive and Negative Differential. These can be used whenever you need a Leading (Positive) or Trailing (Negative) edge to trigger something. I use them all the time.