Table of Contents
Advertisement
Chapter 4.
f)
g)
h)
i)
Note :
a)
b)
c)
4.2.3.
Preventive Maintenance at E-10B
E-10B's local clock (given by HOSA cards) may drift with passage of time
(oscillator stability 10
voltages should be checked on Vas points of all three HOSA cards. The
voltage indicated shall be in between 1.45V to 1.55 V D.C.
If voltages are found to be out of the above mentioned range, these should be
adjusted with the help of a potentiometer mounted on the cards.
Note: Tolerance values may vary from card to card. So if FNU alarm on
HASU is present after connecting to NSE (ie after switch over from
independent to synchronize mode, HASU card can be tuned to match and
RZLP pressed to remove the alarm. Tuning to be done to the effect that no
alarm is present both in independent & synchronize mode.
4.3.
NSE INTEGRATION WITH C-DOT SBMs
4.3.1.
General
C-DOT SBM accept a timing input of 8,192 MHz. NSE4 supplies three
duplicated 8.192 MHz TTL clock output along with 8 KHz SYNC signal.
18
Change the switch on BT bay from INDEPENDENT mode to SYNC
mode. Also reset the button on BT. All the existing non-urgent alarms
should disappear on the HASU card of E-10B exchange.
To verify that NSE output is supplying clock to the E-10B, connect the
Monitoring input (check input) of NSE on connector J18 to the point
shown on the BT bay as shown in the Figure 4.1a. The SYS0 LED on
NSE display panel shall light up.
Slip at E-10B can be monitored by connecting the slip counter at BT
bay at the point shown in the figure.
The slip values on counter shall be noted on daily basis at a particular
time one day before and after synchronisation.
If 'MSEXT' alarm on BT (CIT-1) is red then give a reset to 'HASU' card
and press 'RZLP' switch on 'HASU'.
The 'MSEXT' alarm shall be off to show proper operation.
The NSE 2MHz G.703 output cable length shall be not more than
15 meters.
No oscillator drift messages should apear
-6
). Therefore, before synchronisation, the HOSA card
C-DOT NSE
Advertisement
Table of Contents
