5-3
2.2 Details about the daily test
1. Finishing the test
After the test has finished, the distress signal receiving LED flashes and the external speaker and buzzer
sounds for 2 seconds, and the test results are displayed.
2. MAIN CPU
ROM and RAM tests are executed, and the program version of the main CPU is displayed. If any fault
is found out, “NG” is displayed.
U4 (Flash ROM) is tested by checksum test, U5 (EEROM) by read-write test, and U6 and U7 (SRAM)
by read-write test.
3. MODEM
ROM for DSP is tested, communications between main CPU, DSP, and CODEC are tested, and the
program version of MODEM is displayed. If any fault is found out, “NG” is displayed.
U11 (Flash ROM) is tested by checksum test.
For the communication test, U13 (DSP) receives commands from U3 (main CPU) and controls U12
(CODEC), and the main CPU receives the test results.
4. RCV-1
DSC watch keeping receiver board is tested. If the test result is good, “OK” is displayed, and if not
good, “NG” is displayed.
The 18 MHz carrier signal inputs to the antenna circuit through the capacitive coupling of printed
circuit pattern.
For the test, the mark signal of ‘1700Hz-85 Hz’ and the space signal of ‘1700Hz+85 Hz’ are gener-
ated by shifting the 3rd local oscillator frequency by
+85Hz, and sent to the MODEM. If the MO-
DEM cannot recognize the mark and/or the space tone signal, “NG” is displayed.
5. RCV-2
Daily test of DSC general watch keeping receiver board is executed. The test method is the same as that
of above RCV1. If this receiver is not installed, this line does not appear.
2. Daily Test
U3:MAIN CPU U13:DSP U12:CODEC
MODEM
SYN
18MHz
ANT
Co
RF
(1700Hz + 85Hz)
RX(05P0703)
CONTROL/MODEM
(05P0702)
MODEM
MAIN CPU
DATA
LINE OUT
(SNY-DATA,TEST,FIL-SEL)
456.7kHz + 85Hz
3Lo
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