Ambulances cancelling

Ok.....I know it is found somewhere but I can't find it, so I am asking. There are calls where I know that an ambulance will be needed, so I add an ambulance to the required units for response but the ambulance is released before it gets there only to be "requested" a few minutes later. I know there is a feature that cancels unnecessary ambulances and that it can be turned off, but I can't find it after looking everywhere.. Thanks

Quote from DragonBlade

The settings tab in dispatch center. Its the 3rd option down. It should only stand down EMS units once they have made it on scene not before.

Ok....yes...should have been more specific... they get dispatched and then arrive and then clear...same with EMS Supervisors. I see what you say about the dispatch center... but I can's find what you refer to.. can you screen shot?

Never mind... I found it...thanks for the information