Lanex TM-76, Operating Manual, Page: 15 / 56

E1/G.703 F
IBER
O
PTIC
M
ODEM
O
PERATING
M
ANUAL
IOA76-1F 9 May 2009
contacts in the telecommunication rack are connected to DB- 9 female socket. The detected
failure conditions and actions taken are shown in Table 1.
Table 4. Detected failure conditions and accompanying actions.
Actions taken
LED diode
Re-
lay
1)
E1 channel signal
G.742
frame
bit
Failed
Element
Failure
condition
Alarm
LOOS
LOF
10
-3
10
-6
LDF RAL
LOES
UA
NUA
AIS
Loss of signal UA
;
C O
AIS signals are
transmitted to all E1
interfaces
;
Loss of frame
synchronization
UA
;
C O
AIS signals are
transmitted to all E1
interfaces
;
Error rate
> 10
-3
UA
;
O C
AIS signals are
transmitted to all E1
interfaces
;
Error rate
> 10
-6
NUA
;
C O ---
Transmitter
failure
UA
;
---
Linear optical
Interface
Remote alarm
;
---
Local
interface
E1
G.703,
G.704
Loss of signal UA
;
C O
AIS signal is transmitted
via E1 channel to
multiplexer
Entire device
Loss of power
supply
UA C C

;
– LED diode is on
1)
– alarm relay, an activated alarm is indicated by closed relay contacts (C – closed contacts,
O – open contacts). TM-76.1 version is not equipped with alarm relays.
3.2 Additional channels
A frame is generated in the multiplexing system. The frame includes two bits, which are
used to generate two additional synchronous bi-directional data transmission channels
at the speed of 10 kbit/s each.
The first bit – Alarm Indication Signal Bit is used to transmit an alarm signal to a remote
device.