ATL Telecom AM2048 - Manual (Page 14)

ATL TELECOM USER GUIDE
AM2048A
25
4.10.2 Timing
For a full treatment of the timing options, see section 4.9.
4.10.3 Framing
4.10.3.1 Unstructured Operation
FIGURE 4.10.1: UNSTRUCTURED OPERATION
For unstructured working, Loss of Frame Alignment and AIS alarms are suppressed. The user
data passes transparently through the system. An arbitrary frame position is assumed for
mapping the user data in to the line pairs. The user data may or may not have TS0, and may
or may not be using CRC4.
To set up this configuration, go to the “Configuration > User Port” Menu and select
Rx Unframed
(*)
Rx Framed ( )
Rx CRC4 [ ]
Tx TSO Transparent (*)
Tx TSO Generate ( )
Tx CRC4 [ ]
CRC4G
Tx
TS0 TS0
Rx
CRC4M
FAW
A
SA4
SA5
SA6
SA7
SA8
HDSL
CRC6
CRC4
CRC4M
Rx
FAW
A
SA4
SA5
SA6
SA7
SA8
TS0 TS0
Tx
CRC4G
FAW
A
SA4
SA5
SA6
SA7
SA8
HDSL
CRC6
NTU ELU TE ET
T V3
FAW
A
SA4
SA5
SA6
SA7
SA8
4
24 ATL TELECOM USER GUIDE
AM2048A
4.9.3 Crossing an SDH Network
Both AM2048 sections take their timing from the network and both are configured the same.
Use the configuration shown in section 4.9.2.2.
Note: The SDH network might be configured to provide a PDH path, in which case see
section 4.9.4.
4.9.4 Crossing a PDH Network
In this example, a PDH network is shown where timing is passed transparently from end to
end in both directions. From a timing point of view, this is equivalent to connecting Master A
directly to Master B. To provide a Master clock to the system, side A should be set as in
section 4.9.1.3, otherwise, without a master clock somewhere in the path, the timing will be
unstable.
4.10 G.703 OPTIONS
4.10.1 Impedance
120 Ω and 75 Ω may be selected under software control and set differently at each end of the
link. E.g. CO (Master) set to 120 Ω and the CPE set to 75 Ω . The factory default is for the
AM2048 to auto-detect which interface is being used. Once a signal has been detected on an
interface, the impedance parameter is then set so that after a power OFF-ON event the
impedance is selected immediately. The AM2048 may be set back to auto-detect at any time.
Connect the VT100 terminal emulator to the Master AM2048.
Go to the “Configuration>User Port” Screen to view/change the settings for the Master.
Use F8 to view/change the settings for the slave.
G.703/X.21/V.35/10BaseT/USB
Customer
Terminal
AM2048A AM2048A
G.703
Timing
Master
B
Slave Customer
Terminal
AM2048A AM2048A
G.703
Timing
Master
A
Slave
PDH
Network
G.703/X.21/V.35/10BaseT/USB
G.703/X.21/V.35/10BaseT/USB
Customer
Terminal
AM2048A AM2048A
G.703
Timing
Master Slave
G.703/X.21/V.35/10BaseT/USB
Customer
Terminal
AM2048A AM2048A
G.703
Timing
Master Slave
SDH
Network