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PBJ_N-SH-e-1810.docx
24.1 Information for Inferring the Cause of Board Failure
(All of these balances use only a few boards and the varied functions work in tandem with
each other. It is therefore difficult to determine the failed board from a single breakdown
mode. An educated guess to determine the failed board can be made by understanding the
functions performed by each board.)
24.2 1Assy,Display (B4)
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Function <controls every function>
Its main functions are: (1) To supply power to everything except the I/F board (logic 5V,
analog ±12V, and LCD backlight power) (2) Display function (3) Clock function (4)
Storage of balance constants (5) Man-machine key input (6) Weight loading control (7)
RS232C communication control (8) Other external communication (printer, external input/
output, extended communication) functions (9) Control to the Analog board.
Detailed Contents
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Supplying power: the Assy,Display (B4) logic power 5V. Power supplied to the
Assy,Analog (B3) is ±12V. 16V/100mA power is supplied for the backlight.
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Display: Displays the weight values etc. on the basis of signals coming directly from the
CPU. (3) Clock: The IC for the clock (driven by the backup battery) is directly controlled
by the CPU.
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Memory: St
ores the balance constants and the user’s balance usage modes.
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Man-machine key input: A series of man-machine interfaces including power ON/OFF.
For setting the balance environment status modes and setting the clock etc.
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Calibration weight loading control: Controls the position, working together with the
calibration weight loading device. Also controls the drive torque.
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RS232C communications control: Controls communication with PCs as an external
peripheral (via IC M105).
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The I/O port controls communication with external printers. It controls communication with
external keys (e.g. AKB301) for key port, as well as having an external contact output
function. Other multi-purpose communications ports are controlled directly by the CPU as
extension ports.
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Controls the balance weight value A/D and the communication of temperature
measurement A/D with respect to the Analog board and receives data.
24.3 Assy,Analog (B3)
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A) Function <mainly weight measurement>
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(PID control (mechanical control) (2) Load value A/D control (3) Temperature A/D control
(4) Magnet temperature correction (span calibration) (5) Generation of reference voltage.
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Detailed Contents
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Mechanically controlled servo: Controls the static balance of the load and the
electromagnetic force for measurement with respect to the weighing capacity
measurement mechanism.
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(Load measurement A/D: Reads the electrical current of the coil generating the
electromagnetic force for measurement to calculate the raw data value (wAd).
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Temperature measurement A/D: Calculates the A/D and value (tAd) which measures the
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temperature inside the magnet generating the electromagnetic force. Corrects the
displayed load.
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Magnet temperature correction: Temperature correction of the magnetic flux density.
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Reference voltage generation: Used mainly as the reference voltage of the A/D converter
(the voltage which determines the span etc. of the displayed load).
Summary of Contents for PBJ-N
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