Accutorr Plus Service Manual - Mindray

3. Perform NIBP functions.
start measurement
repeat measurement
overpressure limit
enter or exit text mode
abort measurement
enter or exit calibration mode
update alarm limits
report alarm status
report data
4. Transmit/Receive data to/from Temperature module.
5. Manage Recorder functions.
6. Manage Keypad interface.
7. Drive Seven Segment LED.
8. Provide RS232 communications to PC and support software download.
9. Support Service Diagnostics.
2.2.1.3 Detailed Hardware Description
determine inflation pressure
perform controlled cuff deflation
monitor DC and AC pressure and
acquire pulsations
decide on termination point and
exhaust cuff pressure
smooth pulsation data
determine systolic, mean, diastolic
pressure and heart rate
check alarm conditions
Microcontroller, U1
Device U1 is an MC68302, which contains a 68000 core CPU, a 24-bit address bus and
a 16-bit data bus. Clock oscillator, Y2, shall operate at a clock speed of 16MHz which is
used to clock U1. Three serial channels are used. One for communication to the
temperature modules via J4. The second for communication to an external port for PC
applications via J3. The third for communication to the SpO2 module. The MC68302
also offers a Serial Communication Port (SCP), which interfaces to the NIBP A/D. The
recorder interface is via the IDMA channel with buffering through a transceiver of all
data to the recorder.
The power-on reset to the microcontroller and the rest of the system is generated by a
DS1239 micromanager (U19). The DS1239 also acts as a watchdog to the microcontroller.
The ST* input must see a high to low transition every 100ms maximum by the
ST_WDOG* signal (an addressable signal from the microcontroller), otherwise a reset
will be generated.
Upon a reset, both RESET* and HALT* will be activated through buffer U18
(74HCT125). These signals are bi-directional at the MC68302, therefore U1 could
perform a system reset.
2-10 Revised 12/20/00
Accutorr Plus Service Manual
Chapter 2 - Theory of Operation