7
Modes and Functions
There is often no way to know by inspection or by
audio monitoring if the wire pair you are connecting to
is a high-speed data line or not. Most high-speed data
is above the human hearing range so listening to the
line in Monitor mode may not allow you to identify it
as a data line. If you see the
DATA DETECTED
message,
chances are you have accidentally connected to a data
line. If so, disconnect the test set from the line, being
careful not to short the clip leads together in the
process.
Caution
If you have accidentally connected to a data
line, do not press the down arrow because
overriding will cause the test set to go off-
hook and take the data service down.
In some situations you may want to go off-hook, as
described in the next section.
Data Lockout Override
Caution
Shorting the Tip and Ring leads together
while connected to a data line will cause
disruption to the data.
Whenever you try to go off-hook on a high-speed data
line, the TS25D Test Set will go into Data Lockout mode
and will not go off-hook. This is to protect data
services, most of which would be corrupted by loading
the line with the low impedance of an off-hook
telephone. But ADSL (Asymmetrical Digital Subscriber
Line) is a different circumstance.
ADSL is a high-speed data service intentionally
designed to co-exist on the same wire pair as standard
analog telephone service. If you try to go off-hook on a
wire pair carrying both ADSL and analog telephone
service, the TS25D Test Set will detect the ADSL data
signal and go into Data Lockout mode as it would on
any data line. You will see the message
DATA
DETECTED, DOWN ARROW TO OVERRIDE
. Now, if you
want to go off-hook to access the analog phone service
sharing the line with ADSL, press the down arrow as
instructed on the LCD.
The test set will override the lockout, will go off-hook
and draw dial tone without disturbing the co-existing
ADSL service. The TS25D Test Set has circuitry that
protects the ADSL service when it is off-hook. Going
off-hook on ADSL lines is the most common use of
Lockout Override.
There is another case where the override function may
be needed. You may encounter the rare circumstance
where the analog telephone line you connect to is not
carrying any data but there is enough high frequency
noise on the line that theTS25D Test Set thinks there is
high-speed data on the line. If you know you are
connected to such a line, use the Lockout Override
function to go off-hook. This usually only happens
when the telephone line is near a commercial AM
radio broadcast antenna.
There is a provision for turning the data lockout
function off. When Data Lockout is turned off, the test
set will go off hook on a powered line when switched
to Talk (
T
), even if data is present. When Data Lockout
is off, the test set will still detect data in Monitor mode.
To learn how to turn Data Lockout on and off, refer to
the System Configuration section.
High Voltage Lockout
Caution
Do not short the test set leads to each other
while it is connected to a line carrying high
voltage.
The TS25D Test Set is designed for use in environments
where analog voice lines co-exist with lines that carry
high DC voltages. When the TS25D Test Set is switched
to Talk mode, it tests the line for high-speed data and it
measures the DC voltage on the line before it goes off-
hook. If the DC voltage exceeds 140 V, the test set will
prevent itself from going off-hook and will display
HIGH VOLTAGE LOCKOUT
.
