Hitachi RAS-25CNH2 - Page 42

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● Fig. 2-1 shows the interface circuit used for the indoor and outdoor micro computers to communicate with
each other.
+
–
+
–
+
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Indoor P.W.B.
Outdoor P.W.B.
Terminal board
Terminal board
CD
CD
D101
I/F 0V
C801 R802
C802
0V
0V 0V0V
5V 5V 5V
0V
0V
0V
5V
0V
C806
R810
R811
C804
0V
IC801
C803
0V
0V
0V
I/F 0V
0V
IF transmit
output (SDO)
IF receive
input (SDI)
MICRO
COMPUTER
5V
5V
5V
12V
5V 5V
5V
5V
5V5V
5V
C805
R812
R813
C808
64
19
IF transmit
output (SDO)
IF receive
input (SDI)
MICRO
COMPUTER
AX-8J00
70
11
32
69
33
0V
L701
C801 R802 Q802
R801
R813
0V
0V
0V
0V
0V
0V0V
C710
NF COIL3
C708
C709
Interface
relay
36V
(Communications from indoor micro computer to outdoor micro
computer)
(Communications from outdoor micro computer to indoor micro
computer)
Fig. 2-1 Indoor/outdoor interface Circuit