2-4-2. Switch, Indicators, Audio and2-4-3. Indicators, Audio and Communication
Communication Circuit Check by anCircuits Check by EA-80 connected to
OscilloscopeLLC-8000
1. Connect the pin 7 of CN1 on the AU-254 board to the +1. Press the POWER switch on the LLC-8000 to turn the
terminal of the power supply, and the pins 1 and 2 oftotal LLC-8000 system on.
CN1 to GND of the power supply.(Do not press the ATTEND button on the LLC-8000.
Use the modified RK-8XXX cable to facilitate theNot pressing the ATTEND button does not light the
check required. (Refer to step1 in 2-4-1. Switch,indicator located at the left-above the monitor button on
Indicators and Audio Circuit Check.)the LLC-8000.)
2. Connect the pin 4 of CN1 on the AU-254 board to2. Check switches, indicators and audio circuit by the
GND of the power supply.same steps as steps 3 through 7 in 2-4-1. Switch,
3. Set a DC out voltage to +15 V, and turn on the powerIndicators and Audio Circuit Check.
switch.3. Communication circuit check.
4. Two seconds later, all response indicators (D1 throughWhen the communication is established, the indicator
D6 on the SW-952 board) flash.that shows the student unit, EA-80, being checked and
5. Disconnect the pin 4 of CN1 on the AU-254 boardlocated at the left-above the monitor button on the
from GND of the power supply.LLC-8000, lights.
6. With transmitting O55H� code from the pin 3 of IC14. Press the POWER switch on the LLC-8000 to turn the
(TxD terminal) on the SW-952 board, all responsesystem off.
indicators light.
With all response indicators flashing, that is, without
lighting, it is abnormal. Check the signals between the
pin 1 of IC1, the pin 3 of IC1 and the pin 4 of CN1 on
the AU-254 board.
7. (a) Switches and indicators check
Perform the same step as step 7(a) in 2-4-1. Switch,
Indicators and Audio Circuit Check.
(b) Audio circuit check
Perform the same step as step 7(b) in 2-4-1. Switch,
Indicators and Audio Circuit Check.
(c) Communication circuit check
Using an oscilloscope, confirm that O55H� code is
transmitted to the pin 4 of CN1. With transmitting
O55H� code to the pin 4 of CN1, it shows the following
waveform on the oscilloscope.
b6b?
TXD TERMINAL
"55 H"
1101010
Start bitStop bit
55H
0.42 msec
EA-80
2-4 |
ACEC
