Black Box LES1508A - Page 317

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724-746-5500 | blackbox.com Page 317
RS-232 Standard Pinouts
The RS-232 pinout standards for the DB9 (and DB25) connectors are tabled below:
DB25
SIGNAL
DB9
DEFINITION
1
Protective Ground
2
TXD
3
Transmitted Data
3
RXD
2
Received Data
4
RTS
7
Request To Send
5
CTS
8
Clear To Send
6
DSR
6
Data Set Ready
7
GND
5
Signal Ground
8
CD
1
Received Line Signal Detector
9
Reserved for data set testing
10
Reserved for data set testing
11
Unassigned
12
SCF
Secondary Rcvd Line Signal Detector
13
SCB
Secondary Clear to Send
14
SBA
Secondary Transmitted Data
15
DB
Transmission Signal Timing
16
SBB
Secondary Received Data
17
DD
Receiver Signal Element Timing
18
Unassigned
19
SCA
Secondary Request to Send
20
DTR
4
Data Terminal Ready
21
CG
Signal Quality Detector
22
9
Ring Indicator
23
CH/CI
Data Signal Rate Selector
24
DA
Transmit Signal Element Timing
25
Unassigned
FEMALE
MALE
25 pin DB25
9 pin DB9
8 pin RJ45