Lerch Bates Inc. Building Insight

Global Leaders in Technical Consulting for the Building Industry

Destination Control Observations

The latest and the greatest elevator innovation that is available on high end elevator control systems is Destination Control.  All of the major manufacturers of elevator control systems have their own version of Destination Control.   Schindler Elevator had the first installation in our market and leads the pack in total number of units, though Otis is not far behind.

Destination Control is available on both modernizations and new installations.  We are completing our first modernization project with destination dispatching control in the San Francisco office and I want to offer some of my observations:

First of all, while learning to use destination systems is very intuitive to the everyday user, the way in which the elevator control system actually assigns the calls is not necessarily so.  These systems have so many possible settings, and more and more are being added every day, that the technicians installing them often have only a basic understanding of the systems capabilities.  That’s not a knock on these guys.  Even the expert adjusters are discovering new wrinkles.

The systems use complicated algorithms and calculations to determine which car to assign to any given call and how to group calls together.  That does not mean that the first call entered will necessarily be the first call answered.  It also does not mean that a call will necessarily be answered in what seems to be the most logical way.
Let me provide an example:  the High Rise elevator group in this building has five cars, one of which doubles as a service car and provides service to one floor above and one floor below the levels served by all other cars in the group.  Destination Control is ideal for this type of application because there are, in effect, no hall calls, but only car calls.  If you want to travel to the 31st floor and there is only one car that serves the 31st floor, then the system knows which car can answer your call and sends that car to pick you up.  In a conventional two button system, you have only a one in five chance of getting the car that will take you to the 31st floor unless special controls are provided.

However, if you want to go from the first floor to the lower level, we’ll call it floor  0 (zero), and there are other calls in the system when you are picked up, the destination system may decide to take you all the way to 31 before taking you to 0.   I’m not entirely sure why this happens, and neither is the technician on the job, but I believe it has something to do with the elevator system trying to provide the overall best average “time to destination” and your short run from 1 to 0 just does not meet the necessary requirements.

There are adjustments that can be made to the system to prevent this from happening, since it doesn’t seem logical to take you all the way to the top of the building before going to just one level down.  But then, some other setting is changed, and you have another issue to deal with, such as the system telling you, “Sorry, no car available.  Try your call again.”  And in fact, the system can be programmed to say exactly that, or any other way you want to tell the passenger that they are out of luck, at least for the moment.

The possibilities of Destination Control seem to be endless.  One cool feature is VIP Service.  For that extra special tenant, you can provide a special code which, when entered, will assign a single car to that call and will take no other calls, thus giving Mr. VIP an express ride, all alone, to his desired destination.

But in the Post 9/11 era, probably the most popular feature of Destination Control systems is the ability to interface with card readers and building security systems to not only control, but monitor, who is going where.

By the time you read this, there are probably new possibilities, and most certainly new experiences with Destination Control.  Please share.

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