Procom 4NSA User Manual
Data Sheet
4NSA
LF Interface Module, 4-Wire
The low frequency (LF) interface module is designed for the switching on of 4 call
stations in four-wire technology.
At a Glance:
• Switching-on of up to four call stations
• Call station monitoring from the control unit
• Monitoring of call station voltage
• LF monitoring function (special model)
• Establishing long-distance lines
• Sending/receiving level can be regulated
• Special functions (optional)
Fig. 4NSA (L- No. 2.300)
Date:
13.03.2009
Page:
1/4
© 2008 ProCom, All rights and technical changes reserved
Author: HS Document-No.:
DB_4NSA_ 2300_01
Data Sheet
4NSA
LF Interface Module, 4-Wire
The principle functions of the 4NSA are illustrated in the following block
diagram.
C
S
a
p
l
r
e
l
c
h
S
s
t
t
a
e
t
l
i
l
o
e
n
C
S
a
p
l
r
e
l
c
h
S
s
t
t
a
e
t
l
i
l
o
e
n
Sa
Sb
La
Lb
+
Sa
Sb
La
Lb
+
Satz 1
Set 1
-48V
Satz 4
Set 4
-48V
4NSA
+
Modem
CODECCODEC
+
+
Modem
+
S
C
e
O
u
N
e
R
r
O
u
n
g
t
T
L
+5V
GND
-5V
KS
BUS
-48V
+0V
Block diagram 4NSA
The 4NSA has four independent sets. One call station with two wire pairs can be
connected to each set. If the 25 W booster amplifier of a call station is activated or
connected then two additional wires are necessary for voltage supply.
With a four-wire connection, jumpers on the backplane are necessary for the supply.
The voltage feed (-48 V) of each 4NSA set is fused with a 1.6 A fuse. If a fuse has
been triggered then the fuse LED switches off on the front plate and a message is
sent to the processor module CPU1.
The functionality of the LF module can be programmed per set using the
configuration software ICS. Control frames are sent bidirectionally over the modem
line (S
) cyclically between the 4NSA set and a call station. If a subscriber (call
a/Sb
station) is absent then an error frame is sent to the CPU and the sending/receiving
LED blinks slowly.
This monitoring function can be disabled in the ICS.
The analogue voice signal from the LF line (L
) is digitized on the 4NSA and
a/Lb
transmitted to the PCM bus.
Date:
13.03.2009
Page:
2/4
Author: HS Document-No.:
© 2008 ProCom, All rights and technical changes reserved
DB_4NSA_ 2300_01
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