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342-86400-447PS
Issue 1
March 1994
Page 8
Copyright
GE Power Management 2001
3. FRONT PANEL FEATURES
Led Indications
Alarm (red)
Denotes when the unit has lost either Shelf Framing, Data
Framing or operates at an out of temperature range. Shelf
Framing refers to the 2 kHz shelf SYNC clock and must first
be established before a Data Framing alarm can occur. After
shelf SYNC has been detected, the local and remote units
exchange messages to establish Data Framing. Shelf
Framing alarms usually occur if there are no JIF or JMUX
units present.
Xmt and Rcv (green)
These leds are green (steady) if the ports have been
configured but no data activity is present on the transmit or
receive terminals. These leds are green (blinking) if data
transitions are occurring on the transmit and receive
terminals.
Note: All led indications are controlled by the micro-
processor.
Push-button (ACK)
The main use is a led and micro-processor test; pressing the button causes all
the leds to light.
The second use is to put the micro-processor into a "Forth Loop" state. In this
condition, the micro ignores all settings until the JCI software is run. The JCI will
automatically clear the Channel Assignment setting (--) at which point the user
can configure the unit to the desired settings. If the unit is inserted with the ACK
button pressed and then removed and inserted normally (no JCI), all previous
settings will return.
Craft Interface (C.I.) Jack
This is a serial RS232 9600 b/s port for connection to a 386 or better PC. The
supplied JCI software enables the user to configure the unit and monitor the
units status.
LS-DATA UNIT
C.I.
86447-01
ACK
RCV
ALARM
XMT
4
3
1
2
Figure 1
Front Panel Layout