RAD Data comm ASMI-450 - Manual (Page 94)

Diagnostics
5-6 ASMi-450 Installation and Operation Manual
5.3 Test Functions
Test Functions The ASMi-450 supports the following types of test functions:
•
Local loopback on the user's port of the local ASMi-450 (LOOP LOCAL
PORT).
•
Remote loopback on the user's port of the remote ASMi-450 (LOOP REM
REM PORT).
The loopbacks are not available for an ASMi-450 with the Ethernet interface.
The user-controlled test functions are accessed from the TEST OPTIONS menu.
In addition, when the internal jumpers ALB and RLB are set to EN (see Section
2-4 for detailed instructions), the LOOP LOCAL PORT and LOOP REM REM
PORT loopbacks, respectively, can also be enabled via the corresponding
CCITT Rec. V.52 pins in the DCE connector.
The available test functions are described in the following paragraphs. The test
functions are identified by the designation displayed by the ASMi-450.
LOOP LOCAL PORT
When activated, the local user's port loopback returns the signal received from
the user's DTE, after passing through the user's port interface of the ASMi-450.
The local loopback is formed by connecting the transmit signal, provided by the
user's port interface to the processing circuits, to the input of the receive path of
the user's port interface. The test signal is provided by the DTE connected to the
ASMi-450, that must receive its own transmission without errors while the
loopback is activated. During the loopback, the local ASMi-450 continues
sending the user's data to the link.
Figure 5-1 shows a typical local user's port loopback.
This test is generally used to check the connections between the DTE and the
ASMi-450.
Figure 5-A. LOOP LOCAL PORT Loopback
REMOTE ASMi-450 LOCAL ASMi-450
User
Interface
Processing
HDSL Line
Interface
HDSL Line
HDSL Line
Interface
Processing
User
Interface