Pots Subscriber Search Tone Test - Huawei SmartAX MA5612 Maintenance Manual

SmartAX MA5612 Multi-service Access Module
Maintenance Guide
Result
The conclusions of the POTS subscriber loop line test are as follows:
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The fault can be located and troubleshot according to the preceding conclusions.
Reference
In many cases, the voice service faults (such as there is no tone after offhook or there is noise
during the communication) are caused by the subscriber loop line. Therefore, the subscriber loop
line test is used to check whether the subscriber loop line is normal. This helps locate the faults.

8.5 POTS Subscriber Search Tone Test

The search tone test allows an MA5612 to send a voice signal with a certain frequency and
amplitude to a plain old telephone service (POTS) line. A maintenance engineer then checks
whether the POTS line receives the signal on the peer side using a phone receiver or other special
instrument. This method helps to determine whether the line is faulty. In addition, the search
tone test helps to locate a specific line among multiple lines.
Context
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Issue 01 (2012-07-25)
Normal: The subscriber loop line is normal.
Touching the power line: The subscriber loop line touches the power line.
Line A mixed with other lines: Line A touches other subscriber loop lines.
Line B mixed with other lines: Line B touches other subscriber loop lines.
Line A and line B mixed with other lines: Line A and line B touch other subscriber loop
lines.
Line A grounding: Line A is connected to the ground.
Line B grounding: Line B is connected to the ground.
Line A and line B grounding: Line A and line B are connected to the ground.
Self-mixing (small resistance and self-touch wire): Line A touches line B.
A-B poor insulation: The insulation between line A and line B is poor.
A-ground leakage: Creepage to ground occurs on line A.
B-ground leakage: Creepage to ground occurs on line B.
Creepage of line A and line B to ground: Creepage to ground occurs on line A and line B.
Telephone unconnected: The subscriber loop line is not connected to a phone or the
subscriber loop line is broken.
Off-hook: The phone of the subscriber is offhook.
The search tone test does not depend on the service status of a port. In other words, the test
is executed after being started.
The search tone test cannot be implemented when other tests are being performed, such as
the circuit line test, subscriber line test, emulation test, signal tone test, and loop test.
The search tone test cannot be performed when the port is prohibited.
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