Keyspan 1.9 - Manual (Page 30)

7.1.d - Serial Port Pin Outs
The pin assignments for the Keyspan High Speed USB Serial Adapter's male DB9 port are
illustrated below:
Keyspan High Speed USB Serial Adapter's
male DB9 port
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
Keyspan:High Speed USB Serial Adapter for Mac OS-v1.9 User Manual
This User Manual applies to the Keyspan High Speed USB Serial Adapter Software for Mac OS.
(rev 02may12JA)
Page 30