Hardware manual

Electra Elite Issue 8
System Hardware Manual 5 - 65
4.12.5 Alarm Conditions
A brief description of each alarm condition referred to
under the SW2, position 0 alarm indications is given
below.
Layer 1 Status
LED Lights red when layer 1 is active. The LED is
off when layer 1 is inactive.
Controlled Slip indication (SLIP)
When the difference between the timing of a
synchronous receiving terminal and the received
signal exceeds the buffering ability of the
synchronous terminal, the LED lights red.
Remote Alarm Indication (RAI) Detection
When RAI is received the LED lights red.
Loss of Frame (LOF) Condition Detection
When two of the four or five framing data bits
received are in error, the LED lights red.
Alarm Indication Signal (AIS) Detection
When the system is receiving an Alarm Indication
Signal from a PRT trunk, the LED lights red.
Cyclic Redundancy Check (CRC) Error Event
Detection
When a CRC Error occurs, the LED lights red.
Active Call
LED Lights red to indicate an active call.
LED 11 Channel 23 N/A Channel Busy CO Trunk 23 Busy
LED 12 Not Used N/A Not Used Not Used
Table 5-24 PRT(1)-U( ) ETU LED Indications (Continued)
LED Description On Flashing Off