Motorola MCX600E, Руководство по обслуживанию

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Open Controller
Theory of Operation 4-3
While EMERGENCY CONTROL is low, SW B+ is on, the microprocessor starts execution, reads
that the emergency input is active through the voltage level of EMER IGN SENSE, and sets the B+
CONTROL output of the ASFIC pin B4 to a logic high. This high will keep Q0611 switched on
through Q0612. This operation allows a momentary press of the emergency switch to power up the
radio. When the microprocessor has finished processing the emergency press, it sets the B+
CONTROL line to a logic 0. This turns off Q0611 and the radio turns off. Notice that the
microprocessor is alerted to the emergency condition via line EMER IGN SENSE. If the radio was
already on when emergency was triggered then B+ CONTROL would already be high.
2.5 Mechanical On/Off
This refers to the typical on/off button, located on the control head or mic, and which turns the radio
on and off. If the radio is turned off and the on/off button is pressed, line ON OFF CONTROL goes
high and switches the radio on as long as the button is pressed. The microprocessor is alerted
through line ANALOG 3 which is pulled to low by Q0925 (Control Head with display) while the on/off
button is pressed. If the software detects a low state it asserts B+ CONTROL via ASFIC pin B4 high
which keeps Q0612 and Q0611, and in turn the radio switched on.
If the on/off button is pressed and held while the radio is on, the software detects the line ANALOG
3 changing to low and switches the radio off by setting B+ CONTROL to low.
2.6 Ignition
Ignition sense is used to prevent the radio from draining the vehicle’s battery because the engine is
not running.
When the IGNITION input (J0400-10) goes above 6 volts Q0612 is turned on via line IGNITION
CONTROL. Q0612 turns on SW B+ by turning on Q0611 and the microprocessor starts execution. A
high IGNITION input reduces the voltage of line EMER IGN SENSE by turning on Q0450. The
software reads the line EMER IGN SENSE, determines from the level (Emergency has a different
level) that the IGNITION input is active and sets the B+ CONTROL output of the ASFIC pin B4 to
high to latch on SW B+.
When the IGNITION input goes below 6 volts, Q0450 switches off and R0449, R0450 pull line
EMER IGN SENSE high. The software is alerted by line EMER IGN SENSE to switch off the radio
by setting B+ CONTROL to low. The next time the IGNITION input goes above 6 volts the above
process will be repeated.
2.7 Hook RSS
The HOOK RSS input is used to inform the µP when the Microphone’s hang-up switch is engaged.
Dependent on the radio model the µP may take actions like turning the audio PA on or off.
The signal is routed from J0101-3 and J0400-14 through transistor Q0101 to the µP U0101-23. The
voltage range of HOOK RSS in normal operating mode is 0-5V.
To start SBEP communication with the radio this voltage must be above 6V. This condition generates
a µP interrupt via VR0102, Q0105, Q0104, Q0106 and enables the BUS+ line for communication via
Q0122, Q0121.
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