25/08/2004 ©
Söring
Service-Manual Arco- and RF-units
1
not valid for A-3000/ -2000
2
not valid for Arco-2000
-25-
3
not valid for MBC600
4
not valid for Arco-1000
3. Description of microcontroller unit, board CPU
3.1. General description
The CPU is the central control-system of the equipment. It gets information from other
units by parallel data-lines or via the I
2
C-bus. Data output is performed via the
addressable systembus, by pulse-with modulated signals or as for data input by parallel
data-lines respectively the I
2
C-bus. Analogue input-data are digitized by the processor.
An output for connection of loudspeakers is provided. Furthermore there is a possibility to
communicate with other equipment via a serial interface.
3.2. Connection to other units
3.2.1. Connection to frontpanel
The CPU is connected to the frontpanel via the I
2
C-bus. Input of commands is done by
reading the different I
2
C-input-chips. Output of data for display is done by writing to the
corresponding I
2
C-output-chips. Furthermore, the CPU-board delivers power to the
frontpanel.
3.2.2. Connection to handpiece recognition unit
Data transfer between CPU and handpiece recognition unit is done via parallel data-
lines. The handpiece recognition unit needs support from the CPU in order to detect a
handpiece. Different possibilities about the wiring of the connected handpiece are
investigated and the result of this investigation is passed back from the handpiece unit to
the CPU. The CPU is thereafter in a position to identify the correct handpiece. As an
additional function the handpiece recognition unit delivers the status of footswitches over
the data-lines.
3.2.3. Connection to high-power supply
The high-power supply receives its information about the voltage desired over the
equipment-bus. There is no further direct connection to the high-power supply.
3.2.4. Connection to Cut-module
4
The Cut-module receives its control-information via the equipment-bus. A function check
of the Cut-module is performed indirectly by the current consumption of the high-power
supply.
3.2.5. Connection to Coag-module
As the Cut-module the Coag-module is also controlled via the equipment-bus. The
monitoring is also made indirectly by checking the supply-current.
3.2.6. Connection to relay board
The relay board is the central distributor for the RF-power currents. Controlling is done
via the equipment-bus. A relay connects an input-module to a handpiece. All other
handpieces and the other RF-module are disconnected, thereby obtaining an optimum on
functional safety.
Furthermore the relay board sends the power-supply data current, voltage and mains
breakdown to the CPU. Measurement of RF-leakage current delivers the RMS-value of
the leakage current as an analogue signal to the CPU. Exceedance of the limit is
transferred to the CPU as a digital signal.
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