AVT MAGIC ISDN, Описание аппаратуры

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PA G E 5 5
ANNEX 2 I N T E R F A C E S
In the following, all interfaces of the system are described.
A2.1 Extension Bus
The Extension Bus socket is used to connect individual MAGIC units with the
bus for the transmission of control signals and encoded audio data..
Connector: Extension Bus (25-pole SUB-D)
Pin Signal Electrical characteristics
1
Shield Data rate: 64-kbit/s to 2.048-Mbit/s
(Total data rate with
J.52 data
Level: V.11, symmetrical
Protocol for RS-485:
1 Start bit
8 Data bits
1 Parity bit
1 Stop bit
Data rate: 19200 Bd
2
TXa Transmit Data
3
Ca Control
4
RXa Receive Data
5
CLK48a
a
Clock 256
×
48 kHz
a Is only used if more than four systems are connected to one bus
6
CLKa Clock Receive
7
8
GND Ground
9
TXb Transmit Data
10
Cb Control
11
RXb Receive Data
12
CLK48b
a
Clock 256
×
48 kHz
13
CLKb Clock Receive
14
CTa Control RS485-Bus
15
CTb Control RS485-Bus
16
C_DATAa RS485-Bus
17
C_DATAb RS485-Bus
18
RXD_Va Receive_D_Valid
19
RXD_Vb Receive_D_Valid
20
TXD_Va Transmit_D_Valid
21
TXD_Vb Transmit_D_Valid
22
FSa Frame_Sync
23
FSb Frame_Sync
24
CLK48a Clock 256
×
48 kHz
25
CLK48b Clock 256
×
48 kHz