Service Manual
Description of the LC2 electronics
23.07.07 Kr/Rei
Page 2(6)
30-34-00-745
Hold + warning
triangle
Hold indicates that the weight display has frozen. The warning triangle
signals that the weight displayed on the scale is not verifiable.
TARE, NET
Tare or Net show that a weight on the scale has been tared out.
cm
The value displayed corresponds to body height in cm. (BMI)
lbs
The weight value is displayed in lbs.
kg
The weight value is displayed in kg.
sts
The weight value is displayed in lbs and sts.
Power supply
Power supply is provided via the LC module bus. The power supply for the display module is
connected through the start button. Once the microcontroller on the LC display module has started, it
assumes control of the power supply. When the start button is pressed again, the power supply to the
display is switched off.
Operation
With the exception of the start button (if provided), the connected buttons can be configured as
required for the particular model. These buttons can be pressed just lightly or longer (longer than 1 s).
Scale service
To activate scale service, 2 contact pins on the PCB must be short-circuited by means of a
jumper/switch. Access to these contacts can only be gained by destroying the seal and opening the
display housing. After placing the jumper, switch on the scale to start scale service.
LC module bus
The LC module bus establishes the connection to the LC weight module. The unregulated supply
voltage from the LC weight module is available on the bus. All relevant data is exchanged via a data
line and a clock pulse line.
Pin
Function
Note
1
SCL
Serial Clock TWI
2
GND
Ground
3
SDA
Serial Data TWI
4
Vin
Battery/power supply voltage
Programming interface
The programming interface is a 10-pin interface, which is only accessible after opening the display
housing. The display housing is secured with a seal that must be destroyed to open the housing.
Warning: If the seal is destroyed, verification is no longer valid. A special seca service adapter is
required to access the programming interface.
The service interface can be used to:
- supply the unregulated supply voltage
- measure the regulated voltage for the electronics
- execute the start function
- delete and write new data to the flash memory and the EEPROM of the microcontroller
Programming
The microcontroller contains two types of non-volatile memories that are used for various purposes in
the module.
The following memory types are provided:
