Analog Load Weigher Learn Function - Motion Control Engineering 2000 Manual

The Computer

Analog Load Weigher Learn Function

The Analog Load Weigher Learn Function must be performed before the load weigher system
will perform properly. With the isolated platform load weigher (MCE), the system simply learns
the reference values of the empty and fully loaded car weight. However, with the crosshead
deflection load weigher (K-Tech) and the rope tension sensing load weigher (EMCO), the sys-
tem must learn the reference values at each floor due to the dynamics of the elevator system.
This is necessary because the perceived load at the crosshead varies with the position of the car
in the hoistway due to the changing proportion of the traveling cable hanging beneath the car
and the position of the compensation cables.
The Analog Load Weigher Learn Function is performed as follows:
1. Move the empty car to a convenient floor where the test weights are located. It is best
to have one person in the machine room and another person at the floor to load the
weights.
2. Place the car on Independent Service operation. Place the F3 switch in the up position
and press the N push button to select the Analog Load Weigher Learn Function (scroll-
ing message is displayed)
• ANALOG LOAD WEIGHER LEARN FUNCTION. PRESS S TO START
3. Press the S push button to start. The computer responds with one of two scrolling mes-
sages:
• CAR NOT READY TO LEARN, MUST BE ON INDEPENDENT SERVICE
4. Verify that the car has been placed on Independent Service.
• READY TO LEARN EMPTY CAR VALUES? PRESS S TO START
5. If the empty car values have already been learned and you want to be learn the full car
values, press the N push button (go to step 9). To begin learning the empty car values,
press the S push button. The computer displays the message:
• LEARNING EMPTY CAR VALUES. PRESS N TO ABORT
6. If the Extra Features Menu Option "Analog Load Weigher?" is set to K-TECH, the car
will move to the bottom floor, record the empty car value and then move up, stopping at
each floor to record the empty car value. When the top floor has been reached, the car
will move back to the floor at which the Analog Load Weigher Learn Function was begun
and the computer will display the scrolling message:
• EMPTY CAR LEARN PROCESS COMPLETED. PRESS S TO CONT.
7. If the Extra Features Menu Option "Analog Load Weigher?" is set to MCE, the car will
learn the empty car value and then display the message:
• EMPTY CAR LEARN PROCESS COMPLETED. PRESS S TO CONT.
8. Press the S push button. The computer displays the scrolling message:
• READY TO LEARN FULL CAR VALUES? PRESS S TO START.
9. Place the full load test weights in the car and press the S push button to begin learning
the full car values. The computer displays the message:
• LEARNING FULL CAR VALUES. PRESS N TO ABORT.
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