9
VL-SVN511BX/VL-SVN511CX/VL-SVN511CX1
4 Technical Descriptions
4.1.
What is a Video Intercom?
4.2.
Video Intercom
4.2.1.
Block Diagram
Here is the block diagram of Video intercom system in Fig 1.1.
The image data is converted into NTSC signal by Camera Unit. The NTSC signal is modulated into FM, then transferred to the
Monitor station through the interphone cable. Meanwhile the received FM signal is demodulated into the NTSC in the Monitor
station. The signal is converted into Y/C signal in LCD controller so that the image is displayed on LCD.
Fig. 1.1 Video intercom system block diagram
Next the voice route between the visitor and the responder is as follows:
the voice signal from the microphone of Door station is sent through a hybrid circuit and interphone cable to the speaker of Mon-
itor station. While the responder’s voice from the microphone of Monitor station reaches the speaker of the Door station through
the reverse route.
The Monitor station provides the Door station with DC power supply through the interphone cable. It means that the image sig-
nal, voice data and power are all sent through the interphone cable.
Summary of Contents for VL-MVN511BX
Page 20: ...20 VL SVN511BX VL SVN511CX VL SVN511CX1 Reference Refer to Image Signal in Signal Route P 32 ...
Page 21: ...21 VL SVN511BX VL SVN511CX VL SVN511CX1 Reference Refer to AM Signal in Signal Route P 32 ...
Page 23: ...23 VL SVN511BX VL SVN511CX VL SVN511CX1 8 2 1 Defect of the Main Monitor Station Power Supply ...
Page 24: ...24 VL SVN511BX VL SVN511CX VL SVN511CX1 Defect of the Main unit power supply ...
Page 25: ...25 VL SVN511BX VL SVN511CX VL SVN511CX1 ...
Page 33: ...33 VL SVN511BX VL SVN511CX VL SVN511CX1 ...
Page 34: ...34 VL SVN511BX VL SVN511CX VL SVN511CX1 ...
Page 74: ...74 VL SVN511BX VL SVN511CX VL SVN511CX1 15 1 2 Door Station ...
Page 75: ...75 VL SVN511BX VL SVN511CX VL SVN511CX1 15 1 3 Power Supply Unit ...
Page 76: ...76 VL SVN511BX VL SVN511CX VL SVN511CX1 15 1 4 Relay Box ...
Page 78: ...78 VL SVN511BX VL SVN511CX VL SVN511CX1 15 1 5 2 VL SVN511CX VL SVN511CX1 ...
