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POTS circuit test
Parameter | Description |
Digital Voltage | Digital voltage |
Low Battery | Low voltage (-) |
High Battery | High voltage (+) |
Positive Battery | Positive voltage |
Loop current | Loop current |
Feeder voltage | Feeder voltage |
Ringing current voltage | Ringing voltage |
Ringing current frequency | Ringing current frequency |
VAG | A-G voltage |
VBG | B-G voltage |
Feeder voltage (V) | Feeder voltage (V) |
Ringing current voltage (V) | Ringing current voltage (V) |
Loop current (mA) | Loop current (mA) |
A circuit test on POTS lines checks circuit functions (ringing, feeder, and dial tones) and parameters (feeder voltage and ringing current) to determine circuit status.
POTS loop line test
Conclusion | Description |
Normal | The loop line is functional. |
A/B wire touching the power line | The loop line and the power line are short-circuited. |
Shorted A wire with wires of an adjacent twisted pair | A wire and a loop line are short-circuited. |
Shorted B wire with wires of an adjacent twisted pair | B wire and a loop line are short-circuited. |
Shorted A and B wires between twisted pairs | Both A and B wires and a loop line are short-circuited. |
Grounded A wire | A wire is grounded. |
Grounded B wire | B wire is grounded. |
Grounded A and B wires | Both A and B wires are grounded. |
Shorted wires within the same twisted (small resistance) | A and B wires are short-circuited. |
Poor insulation between A and B wires | The insulation between A and B wires is poor. |
A wire leakage to the ground | A wire to the ground is leaking. |
B wire leakage to the ground | B wire to the ground is leaking. |
A and B wires leakage to the ground | Both A and B wires to the ground are leaking. |
No connected phone | No phone is connected or the loop line is disconnected. |
Off-hook | The phone is off-hook. |
A POTS loop line test checks performance or indicators (inter-line capacitance and resistance) of a POTS loop line and determines the loop line status.
A SELT test automatically tests a DSL line from one end of the line. It is an effective method of evaluating the line quality. Before a line is used or when a line is being used, the SELT test checks key parameters, such as line gauge, line length, and SNR, that affect line quality to obtain line capability and determine the services that can be carried over the line.
SELT Test Specifications
Supports the test on ADSL2+, ADSL2, ADSL, and VDSL2 ports.
Supports a valid distance of 300-2500 m.
Supports a test precision of 15% (available for 0.4 mm and 0.5 mm lines).
The test duration is within 3 minutes.
Only one port on a board can be tested at the same time and multiple ports in the same subrack can be concurrently tested.
Only one port in an entire subrack of some devices can be tested at the same type.
SELT Test Parameters
Frame ID/Slot ID/Port ID
Updated time: year-month-day hour:minute:second
Line length
Terminal status
Gauge specifications
SNR margin (dB), upstream rate (kbit/s), and downstream rate (kbit/s)
QLN tests on static line noises
A
MELT test is a narrowband line test initiated from one end of a DSL line. The
test items include line voltage, resistance, and capacitance. Based on test
results, you can determine whether the line is grounded,
disconnected, or short-circuited.
METL Test Specifications
Supports the test on ADSL2+, VDSL2, and SHDSL ports.
Only one port on a board can be tested at the same time and multiple ports in the same subrack can be concurrently tested.
A MELT test does not affect the broadband services on the tested line and its adjacent lines.
MELT test results can be cleared globally.
The board test precision cannot be set if a SELT test is performed.
The system saves only the latest MELT test data, which can be queried through CLI.
MELT Test Items
AC voltage on subscriber lines
DC voltage on subscriber lines
Insulation (A/E, B/E, A/B, B/A)
Capacitance (A/E, B/E, A/B)
Search tone tests
Thanks.
