12.8. Parallel Connection Detect Circuit
Function:
In order to disable call waiting and stutter tone functions when using telephones connected in parallel, it is necessary to have
a circuit that judges whether a telephone connected in parallel is in use or not. This circuit determines whether the telephone
connected in parallel is on hook or off hook by detecting changes in the T/R voltage.
Circuit Operation:
Parallel connection detection when on hook:
When on hook Q136 is ON, the voltage is monitored at pin 35 of IC501. There is no parallel connection if the voltage is
1.65 V or higher, while a parallel connection is deemed to exist if the voltage is lower.
Parallel connection detection when off hook:
When off hook Q136 is OFF, the voltage is monitored at pin 35 of IC501; the presence/absence of a parallel connection is
determined when the voltage changes by 0.2 V or more.
68
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 ...