Citizen Systems CBM-910 - Manual (Page 32)

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6.4 Electrical Characteristics
(1) RS-232C I/O signals (RD/TD/DTR)
• Input (RD)
Mark = (
−8 V): Stop bit
Space = (+8 V): Start bit
• Output (TD, DTR)
Mark = (
−8 V): For Busy
Space = (+8 V): For Ready
(2) TTL circuit
Input (RESET)
2: TD
SP232ENC
20: DTR
3: RD
25: RESET
12
9
R1 in
R2 in
R1 out
R2 out
13
8
14
7
T1 in
T2 in
T1 out
T2 out
11
10
C1+
C1
−
1
3
16
VCC
VCC
0 0
104
104
104
104
GND
104
GND
15
C2+
C2
−
4
5
V+
V
−
2
6
23: RESET(L)
7: GND
1: FG
(HC04 or equivalent)
RESET 23 :
VCC
104
3.3k
Set to LOW when reset.