Data Communications Signal Levels - HP 2641A Reference Manual

Table 7-9. EIA RS232C and CCITT V24 Interface Data and Control Signals
Installation
CONNECTOR CIRCUIT
R P2 R C
S
13260 S C
2
2 IV
MODEM
3
3 T2
CON-
2 A B
C D 2 T4 DESCRIPTION TO FROM GND DATA TROL TIMING
- A
A A A AA - Protective Ground X
7 H H H
H AB 102 Signal Ground/Common Return X
2 B
B B B BA 103 Transmitted Data
X
X
3 C C C C BB 104 Received Data X X
4 0 0 0 0 CA 105 Request to Send
X
X
5 E E E E CB 106 Clear to Send X X
6 F F F F CC 107 Data Set Ready X X
20 P P P P CD 108.2 Data Terminal Ready X X
22
- -
14 14 CE 125 Ring Indicator X X
8 J J J J CF 109
Received Line Signal Detector
X X
-
- -
-
-
CG 110 Signal Quality Detector Xi
X
23
-
R R R
CH
111 Data Rate Selector (DTE Source) X X
-
-
-
-
-
CI 112 Data Rate Selector (DCE Source) X X
24 -
- S S DA 113 Transmitter Timing (DTE Source)
X
X
15
-
- -
12 DB 114
Transmitter Timing (DCE Source)
X X
17
- - -
13 DO 115 Receiver Timing X X
- -
- -
- SBB 118 Secondary Transmitted Data
X
X
- - - -
- SBB 119 Secondary Received Data X X
19
M M M M SCA 120 Secondary Reque~to Send X X
- - - -
-
SCB
121
Secondary Clear to Send
X X
12 N N N
N SCF
122
Secondary Received Line Detector
X X
Table 7-10. Data Communications Signal Levels
DATA:
Name
Logic
Voltage
CONTROL:
CLOCK SIGNALS:
Space
o
>+3V but <+25V
ON (true)
o
=
ground
Mark
1
<-3V but >-25V
OFF (false)
1
=
+5V
7-27