Panasonic KX-TDA0177XJ / KX-TDA0177X (serv.man2) Service Manual ▷ View online
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KX-TDA0177XJ / KX-TDA0177X
5.2.4.
2W-4W Conversion
It converts 4W-VOX signal used in the PBX to 2W-VOX signal used in SLT, and vice versa. It consists of an operational amplifier in
the HIC and a balanced network in the CODEC. It can control the return loss of the audio data and frequency characteristics. By
modifying the CODEC program, it can match the corresponding impedance.
the HIC and a balanced network in the CODEC. It can control the return loss of the audio data and frequency characteristics. By
modifying the CODEC program, it can match the corresponding impedance.
5.2.5.
DTMF Signal Detection
Each port has its own DTMF receiver. The receiver detects the signal using IC1 for port A through D, IC2 for port E through H, IC4
for port I through L and IC6 for port M through P. The CODEC detects the DTMF data to be effective at EST terminal=H. This infor-
mation is detected in the MPR via SAMSON, then DTMF signal is detected by MPR reading the DTMF receiver data that came
through the SAMSON local bus.
for port I through L and IC6 for port M through P. The CODEC detects the DTMF data to be effective at EST terminal=H. This infor-
mation is detected in the MPR via SAMSON, then DTMF signal is detected by MPR reading the DTMF receiver data that came
through the SAMSON local bus.
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KX-TDA0177XJ / KX-TDA0177X
5.2.6.
Power Supply
A constant-current power supply in HIC provides +30V, ring side 0V grounding to SLC. The maximum feeding current is 30mA.
5.2.7.
Dial Pulse Detection
When a telephone initiates pulse dialing, this feature detects the pulse-dialing signal.
When the telephone initiates dialing, changes in voltage is detected by the RING terminal in HIC, and this information is transmitted
to the HOOK terminal (Example: 3-pin IC200A) as Make=L/Break=H signal. This digital signal is received by CODEC IC (Example:
35-pin IC201) and recognized as dialing signal. Both 10pps and 20pps can be received. The dialing speed is analyzed by software.
When the telephone initiates dialing, changes in voltage is detected by the RING terminal in HIC, and this information is transmitted
to the HOOK terminal (Example: 3-pin IC200A) as Make=L/Break=H signal. This digital signal is received by CODEC IC (Example:
35-pin IC201) and recognized as dialing signal. Both 10pps and 20pps can be received. The dialing speed is analyzed by software.
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KX-TDA0177XJ / KX-TDA0177X
5.2.8.
Hook Detection
The off-hook status is detected when the telephone is off-hook. When a telephone is off-hook, change in voltage is detected by the
RING terminal in HIC, and this information is transmitted to the HOOK terminal (Example: 9-pin IC200A) as OFF-HOOK=L/ON
HOOK=H signal. This digital signal is received by CODEC IC (Example: 35-pin IC201) and recognized as off-hook signal. The off-
hook status is analyzed by software.
RING terminal in HIC, and this information is transmitted to the HOOK terminal (Example: 9-pin IC200A) as OFF-HOOK=L/ON
HOOK=H signal. This digital signal is received by CODEC IC (Example: 35-pin IC201) and recognized as off-hook signal. The off-
hook status is analyzed by software.
5.2.9.
Ring Trip Feature
When the BELL signal is sent out, the off-hook signal from a SLT is detected, and then it breaks the BELL relay.
When the handset of a ringing telephone is picked up, a DC loop is formed in the sequence of "Original bell signal", "Internal electri-
cal resistance of a telephone", "Intercom bell load resistance" (R203A-P:1K
When the handset of a ringing telephone is picked up, a DC loop is formed in the sequence of "Original bell signal", "Internal electri-
cal resistance of a telephone", "Intercom bell load resistance" (R203A-P:1K
Ω), and then "Ground" (Since DC30V superimposed in
the BELL signal). As a result of this, a voltage rise occurs in Intercom bell load resistance" (R203A-P:1K
Ω) in the intercom circuit,
and a voltage is placed on the 9-pin RING terminal. This change in voltage turns off the driver transistor of the BELL relay in HIC,
and it breaks the BELL relay.
and it breaks the BELL relay.
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KX-TDA0177XJ / KX-TDA0177X
5.2.10. Surge Protection
ZNRs installed between T and R, and between T or R and FG protect from extraneous surge.
5.2.11. Self-Diagnosis
A self-diagnosis relay (RL201A) is installed in A port. In the normal operation mode, it breaks the self-diagnosis relay, and in the
self-diagnosis mode, it makes the self-diagnosis relay. In the self-diagnostic mode, A Tip-Ring is connected to the paired Tip-Ring of
the outside-line card via backboard, and self-diagnosis is feasible.
The self-diagnosis of the outside-line card includes outside call pick up, dial pulse transmission, DTMF transmission, BELL recep-
tion and CPC detection.
self-diagnosis mode, it makes the self-diagnosis relay. In the self-diagnostic mode, A Tip-Ring is connected to the paired Tip-Ring of
the outside-line card via backboard, and self-diagnosis is feasible.
The self-diagnosis of the outside-line card includes outside call pick up, dial pulse transmission, DTMF transmission, BELL recep-
tion and CPC detection.
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