Manuel_X_232_EN
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27.01.2016
2. Installation
Some Reflections to the Minimum Load Measurement
Background Information about the Floor Detection
The paragraph
“Configurations“has explained that the CLMI is potentially able to perform a minimum load measurement. For this
purpose following provisions has been made:
-
The possibility to compensate the error factor of the travelling cable (floor detection). The floor detection should be
activated if the maximum weight of the travelling cable amounts 25% of the minimum load.
Example: A minimum load measurement of 40 kg is required. The height of the elevator shaft amounts 12m and the
weight of the travelling cable is 1,5kg/m. According to this, the travelling cable (6m) itself affects the zero point for 9kg
what corresponds 23%. The floor detection must be activated.
-
Prevention of the slow drift of the zero point (e.g. at outdoor elevator shafts and variation of temperature). This function
is always on.
The chosen strategy is important to the achievable accuracy. A schedular rating:
Rank
Installation
Sensor
Equipment
Accuracy
Zero Load
1
Below the ground
X-133-Sxx
Extension cable
Junction Boxes for 4
sensors
2kg
Yes
– without
restrictions
2
Below the car
X-133-Sxx
Extension cable
Junction Boxes for 4
sensors (X-914)
5kg
Yes
– without
restrictions
3
Yoke
2x
X-109-S02-300
Extension cable
(only if needed)
The CLMI is already
prepared for
connecting two
sensors.
20kg
Yes
– with
restrictions
4
Yoke
X-109-S02-300
Extension cable
(only if needed)
35kg
Yes
– with
restrictions
5
Fixed point
X-130-Sxx
Extension cable
(only if needed)
40kg
Yes
– with
restrictions
Rank 1 and 2: Achievable accuracy does not depend on the suspension of the car, slide guide, etc..
Universal, very accurate measuring strategy but often an inconvenient execution.
Rank 3:
Best choice for yoke measurement. By installing a sensor on each journal, torsion forces and
asymmetric bend phenomenon are effectively compensated.
Rank 4:
Easy, robust measuring method, can be used everywhere. Widespread at modernizations.
Friction, hysteresis (etc.) at the slide guidance affect the measurement result.
An optimal choice of the measuring position (point at joke with the biggest elongation) can
reduce the error. If possible use a very elastic yoke.
Rank 5:
Another easy and robust method. This solution suits in every case where no suitable yoke is available.
Beside the already mentioned errors of the slide guidance caused by friction, the errors of the unequal load distribution
in the cable additionally affect the measurement.
In this case a measurement with two force sensors significantly improves the accuracy, by simultaneously measuring
all cable loads 100% with two sensors.
The CLMI calculates with the floor information the weight of the travelling cable and automatically subtracts
this weight from the measured value. So the zero point remains constant on each floor.
For this process, the CLMI needs information about the car
’s floor position. The CLMI can receive this
information through a parallel 6Bit wide interface. The information can be transmitted in Gray code or in
binary code. The signalling lines must be positive switching but the code can be also processed in inversed
logic. (See
“Technical Data” and “Setup Menu”)
Control the function of the floor detection by reading the code in the test menu of the CLMI. (See paragraph
“Advices about Commands” and “FAQ“)
The signal
“Synch“shows the validity of the code from Bit0 to Bit5. A logic “1” (active) signifies the validity of
the code, and the CLMI evaluates the floor information and load information.
If the signal
“Synch“is a logic “0“, the measurement, the current status of the readout and switching status will
be frozen.
There won’t be an evaluation of the load information. The polarity of this logic can be inverted by
changing the parameter “L”, refer to the truth table below.
When the floor detection is online, the signal
“Synch“ can even be used by putting the signal “Door Open” on
the signal “Synch”. The load is only measured as long as the door is open. So, unwanted signals will be
disabled during the ride.
Please note that the signals are galvanically separated and a separate reference potential is needed!
Parameter in the setup menu: E=x, F=x, C=x, L=?, S=x, P=x, I=x, A=x, H=x (x= 0 or 1)
Programmed parameter
L=
Input level “Synch“
Comment/Result
0 = (0-active)
0V/ not connected
Measurement is active mode
0 = (0-active
1
current readout and switching
status is frozen
1 = (1-active)
1
Measurement is active mode
1 = (1-active)
0/ not connected
current readout and switching
status is frozen