i need to write a simple ladder for 20 smokehouses. Each house has a temp controller. when it goes off it turns on a light and sounds a horn. i can get my light to come on and the horns to work also, but i have one reset button to kill the horn. I Can't figure out how to write it that when the reset is pushed it kills the horn on that alarm, but allows the horn to sound if another house goes into alarm state.

Example house one goes into alarm horn sounds i hit the reset button to kill the horn. A moment later house two goes it to alarm the horn needs to sound again.

 

Hard to say how to do it without more info on brand, temp control method, light and horn on each house or a single central one, ect.

Generally for ladder structure you need to do your logic in rungs separate from the output rung. So, conditions for alarm in house 1 in a rung, bit from that resulting conditions rung trigger the alarm output rung.

If single horn, reset will clear the active alarm conditions in all rungs for all houses. Horn would sound again on the next conditional trigger from any house.

 

Simple ladder logic is sometimes complex.

Advice as follows:

Always use a normally closed contact to represent the "normal condition". This is a "cheap" test for wiring faults.

Always "Latch" your alarm condition.

Never utilize a "Auto Reset" for alarm conditions. Handle the reset with logic.

Share this advice with your instructor.

Hope this helps