![background image](http://html.mh-extra.com/html/panasonic/kx-tg5571bxm/kx-tg5571bxm_service-manual_279721066.webp)
12.5. Intercom Mode
1. Press the Base Unit INTERCOM button, and the handset number button ([1] to [8]), then a monitor tone is heard from the
speaker.
2. At the same time, the Handset ring. This status is called “Intercom stand-by”.
3. Then press TALK button of the Handset, the status is changed to “Intercom mode”.
12.6. Telephone Line Interface
Telephone Line Interface Circuit:
Function
•
Bell signal detection
•
ON/OFF hook and pulse dial circuit
•
Side tone circuit
Bell signal detection and OFF HOOK circuit:
In the idle mode, Q141 is open to cut the DC loop current and decrease the ring load. When ring voltage appears at the Tip (T)
and Ring (R) leads (When the telephone rings), the AC ring voltage is transferred as follows:
T
→
L101
→
R111
→
C111
→
Q111
→
DSP pin 3 [BELL]
When the CPU (DSP) detects a ring signal, Q141 turns on, thus providing an off-hook condition (active DC current flow through
the circuit). Following signal flow is the DC current flow.
T
→
L101
→
D101
→
Q141
→
Q161
→
R163
→
D101
→
L102
→
P101
→
R
ON HOOK Circuit:
Q141 is open, Q141 is connected as to cut the DC loop current and to cut the voice signal. The unit is consequently in an on-
hook condition.
Pulse Dial Circuit:
Pin 4 of DSP turns Q141 ON/OFF to make the pulse dialing.
Side Tone Circuit:
Basically this circuit prevents the TX signal from feeding back to RX signal. As for this unit, TX signal feed back from Q161 is
canceled by the canceller circuit of DSP.
66
KX-TG5571BXM / KX-TGA550BXM
Summary of Contents for KX-TG5571BXM
Page 8: ...4 2 Location of Controls 4 2 1 Base Unit 8 KX TG5571BXM KX TGA550BXM ...
Page 9: ...4 2 2 Handset 4 2 3 Charger Unit for Optional Handset 9 KX TG5571BXM KX TGA550BXM ...
Page 10: ...4 3 Displays 4 3 1 Display Items 4 3 2 Menu Icons 10 KX TG5571BXM KX TGA550BXM ...
Page 11: ...4 3 3 Troubleshooting Handset LCD 11 KX TG5571BXM KX TGA550BXM ...
Page 12: ...12 KX TG5571BXM KX TGA550BXM ...
Page 13: ...4 4 Settings 4 4 1 Connections 13 KX TG5571BXM KX TGA550BXM ...
Page 14: ...4 4 2 Guide to Handset Programming 14 KX TG5571BXM KX TGA550BXM ...
Page 15: ...15 KX TG5571BXM KX TGA550BXM ...
Page 17: ...4 4 4 Direct Commands 17 KX TG5571BXM KX TGA550BXM ...
Page 18: ...18 KX TG5571BXM KX TGA550BXM ...
Page 19: ...19 KX TG5571BXM KX TGA550BXM ...
Page 21: ...21 KX TG5571BXM KX TGA550BXM ...
Page 22: ...22 KX TG5571BXM KX TGA550BXM ...
Page 23: ...23 KX TG5571BXM KX TGA550BXM ...
Page 24: ...24 KX TG5571BXM KX TGA550BXM ...
Page 40: ...7 9 5 RF DSP Interface Signal Wave Form Test Burst Mode 40 KX TG5571BXM KX TGA550BXM ...
Page 41: ... Test Burst Mode 41 KX TG5571BXM KX TGA550BXM ...
Page 84: ...19 SIGNAL ROUTE Each signal route is as follows 84 KX TG5571BXM KX TGA550BXM ...
Page 85: ...Each signal route is as follows RF part signal route 85 KX TG5571BXM KX TGA550BXM ...
Page 88: ...22 EXPLANATION OF IC TERMINALS RF PART 22 1 IC701 88 KX TG5571BXM KX TGA550BXM ...
Page 89: ...22 2 IC801 Backside Terminal GND 89 KX TG5571BXM KX TGA550BXM ...
Page 90: ...22 3 IC851 Backside Terminal GND 90 KX TG5571BXM KX TGA550BXM ...
Page 93: ...24 CABINET AND ELECTRICAL PARTS BASE UNIT 93 KX TG5571BXM KX TGA550BXM ...
Page 94: ...25 CABINET AND ELECTRICAL PARTS HANDSET 94 KX TG5571BXM KX TGA550BXM ...
Page 95: ...26 CABINET AND ELECTRICAL PARTS CHARGER UNIT 95 KX TG5571BXM KX TGA550BXM ...
Page 96: ...27 ACCESSORIES AND PACKING MATERIALS 27 1 KX TG5571BXM 96 KX TG5571BXM KX TGA550BXM ...
Page 97: ...27 2 KX TGA550BXM Optional Set 97 KX TG5571BXM KX TGA550BXM ...
Page 99: ...28 3 Charger Unit 99 KX TG5571BXM KX TGA550BXM ...
Page 106: ...Memo 106 KX TG5571BXM KX TGA550BXM ...
Page 113: ...Memo 113 KX TG5571BXM KX TGA550BXM ...