D – serial port pin outs – Keyspan USA-49WG User Manual
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The pin assignments for the Keyspan USB 4 Port serial Adapter’s male DB9 port are illustrated below:
7.1.d – Serial Port Pin Outs
Pin
Name
Signal Designation
1
DCD
Data Carrier Detect (Input)
2
RX
Received Data (Input)
3
TX
Transmitted Data (Output)
4
DTR
Data Terminal Ready (Output)
5
GND
Ground
6
DSR
Data Set Ready (Input)
7
RTS
Request To Send (Output)
8
CTS
Clear To Send (Input)
9
RI
Ring Indicator (Input)
In order to ensure compliance with emission specifications, cables, should be shielded using braided shields and
metal hoods with complete 100% contact between the shields and hoods.
External Loopback Connector Information
The Keyspan Serial Assistant allows you to perform two types of loopback tests – internal and external. The external
test requires the use of a special loopback connector. This connector requires a “DB9 Female Loopback plug” with
the following wiring:
Pin(s) Wired to
Pin(s)
1
<->
4, 8
2
<->
3
6
<->
7, 9