Karel MS128 - II.7. Isdn Adaptor - Ia12, Exp-Ia12

Karel MS128 Installation & Maintenance Guide
Edition 3.2
30
II.7. ISDN ADAPTOR – IA12, EXP-IA12
The IA12 ISDN Adaptor is an ETSI compatible terminal adaptor that serves as an
interface between the ISDN BRA-S0 lines coming through the network terminator
(NT1) of PTT and the analog lines of the MS128 system. The adaptor also supports
many EURO-ISDN facilities for Basic Rate Access.
The function of IA12 ISDN Adaptor is to support the ISDN BRA protocol of the
network in order to make bi-directional conversions between the ISDN BRA lines of
PTT and the analog lines of the MS128 system.
At basic capacity, IA12 ISDN Adaptor is capable of handling one S0 line coming
from NT1 of the PTT. This capacity can be further increased by means of an EXP-
IA12 Expansion Board which can also support one S0 line. Since each S0 line
offers two separate channels, the IA12 alone can convert two analog lines of the
MS128 system to one ISDN BRA-S0 line whereas the IA12 with EXP-IA12 can
convert four analog lines to two ISDN BRA-S0 lines.
The IA12 ISDN Adaptor communicates with the MS128 system through the data
line of KAREL telephones. Due to the current limitation on this data line which also
feeds the adaptor, it is not possible to connect more than three adaptors to the
same system, and the third adaptor cannot have the EXP-IA12 Expansion Board.
As a result, the available ISDN line capacities of MS128 system are illustrated as
follows:
With motherboard only 1 S0 (2 analog lines)
1
st
IA12 ISDN Adaptor
With expansion board 2 S0 (4 analog lines)
With motherboard only 3 S0 (6 analog lines)
2
nd
IA12 ISDN Adaptor
With expansion board 4 S0 (8 analog lines)
3
rd
IA12 ISDN Adaptor With motherboard 5 S0 (10 analog lines)
The IA12 motherboard has one 8-pin RJ45 socket for connection to the S0 line
coming from NT1, two 623K4 type connectors for connection to the A / B terminals
of the analog line on the MS128 system and one 6-pin RJ jack for connection to the
data line of KAREL telephones. The data cable having a connection box at one end
and a 6-pin RJ plug at the other end also comes with the adaptor.
The EXP-IA12 Expansion Board has one 8-pin RJ45 socket for connection to the
S0 line coming from NT1 and two 623K4 type connectors for connection to the A /
B terminals of the analog line on the MS128 system. The EXP-IA12 Expansion
Board also comes with a flat cable for IA12 connection, which is to be attached to
the corresponding 20 pin connectors on the IA12 motherboard and EXP-IA12 card.
The IA12 motherboard also has three LEDs to display the status of S0 lines as well
as the data line. The rightmost LED turns on when the adaptor is synchronized with
the S0 line connected to the IA12 motherboard. The middle LED turns on when the
adaptor is synchronized with the S0 line connected to the EXP-IA12 card. And the
leftmost LED turns on when the adaptor is synchronized with the data line.