User manual

Chapter 2. Port Card Overview
16 Version 1.2 Apr 2006
When the Fiber Multiplexer is ordered with an RS232 Port Card option, a 4-CHANNEL
RS-232 Card and adapter cable are supplied with each DB25 wired according to the following
table.
Signal
Function
DB25
PIN
Circuit Direction Description
Protective
Ground
1 AA <->
Chassis ground.
May be isolated from signal ground.
Signal
Ground
7 AB <-> Common signal ground.
Transmitted
Data
2 BA To MUX UNIT Serial digital data from DTE.
Received
Data
3 BB Fm MUX UNIT
Serial digital data at the output of the Fiber
Multiplexer receiver.
Request to
Sent
4 CA To MUX UNIT
A ON signal to the Fiber Multiplexer when data
transmission is desired.
Clear to
Sent
5 CB Fm MUX UNIT Constantly ON.
Data Set
Ready
6 CC Fm MUX UNIT
Constantly ON,
Except during test loops.
Data Terminal
Ready
20 CD To MUX UNIT
DTR not used, used for a received serial data rate
clock input from the DTE.
Data Carrier
Detect
8 CF Fm MUX UNIT
Constantly ON, except when a loss of the received
carrier signal is detected.
External Transmit
Clock
24 DA To MUX UNIT
A transmitted data rate clock input from the data
source.
Transmit
Clock
15 DB Fm MUX UNIT
A transmitted data rate clock for use by an external
data source.
Receive
Clock
17 DD Fm MUX UNIT
A
received data rate clock for use by an external data
source.
Remote
Loop back
21 RL To MUX UNIT
When on, commands Fiber Multiplexer into remote
loop back.
Local
Loop back
18 LL To MUX UNIT
When on, commands Fiber Multiplexer into local
loop back.
Test Indicator 25 TM Fm MUX UNIT ON during any test mode
Table 2-5 : DB25 adapter cable pin out for RS-232