14-05-2012, 04:55 PM
Design and Implementation of Home Intercom and Security Control Systems for Buildings
[attachment=22028]
INTRODUCTION
Home intercom and security systems for buildings are
used for communication between households and visitors or
guards; they offer talk-back, entrance guard and security
management. In Europe, as houses are mostly of the villa
type, the home intercom emphasizes high stability. In Asian
cities many people are living in big apartment blocks with a
hundred or more families, and the home intercom
emphasizes multi-functionality for many users. There are
many different communication protocols for home intercom,
such as CAN Bus, LonWorks, BACnet, MODBUS-ASCII,
RS-485/RS-422, Ethernet, power line communication and
wireless LAN. CAN Bus was proposed in 1983 in Germany
by Robert Bosch, and the Version 2.0 of CAN Specifications
issued in 1991 is today mostly used in vehicle control
systems and building automation equipment [2].
Application Layer
For the multicasting with Peer to Peer protocol, to identify
the communication between source and destination, the
system needs to have source and destination address in the
packet. For example, if the guard station calls the indoor
machine, the network connector acts like a router. If the
network connector can’t find the destination address in the
routing table, it discards that packet and then sends another
packet to the indoor machine.
For multicasting with Master and Slave protocol there is
one source, but there is a group of destinations for medium
load communication, for example, sending a message for an
Indicator to show the door release.
For broadcasting with Master and Slave protocol there is
one source sending the packet to all devices for high load
communication, for example, the guard station sending an
announcement to all households.
SECURITY OF HOME COMMUNICATION
When the system deals with the communication procedure,
we use the queue or buffer to store the received packets to
prevent the data from being lost. The data transmitted or
received are put in the queue, waiting to be processed. For
example, the system takes an alarm message in the indoor
machine and the message is put in the queue first and then
waits for transmission. Because the alarm message has a
higher priority when the system detects that the medium is
idle, it sends the RTS immediately. Then the system sends an
alarm message or a packet after waiting to receive a CTS.
When the system receives the confirming message, it deletes
the data from the queue.
GUARD AND DOOR STATION
To improve the system performance the central guard
machine is divided into talk-back machine and security
machine. At the door there is the gate machine, used for
video signal, talk-back and entrance lock control. The data
and parameters relating to the gate machine are set up on the
network connectors, and the gate machine calls the indoor
machine or the guard machine by the network connector.
When the design is used for small-scale buildings, just one
button suffices for the indoor machine. But for larger
buildings the design must map the user relations into a twodimensional
array between the logic address and the user
address, as shown in Table VII. The general user address
consists of user number, floor number and room number.
[attachment=22028]
INTRODUCTION
Home intercom and security systems for buildings are
used for communication between households and visitors or
guards; they offer talk-back, entrance guard and security
management. In Europe, as houses are mostly of the villa
type, the home intercom emphasizes high stability. In Asian
cities many people are living in big apartment blocks with a
hundred or more families, and the home intercom
emphasizes multi-functionality for many users. There are
many different communication protocols for home intercom,
such as CAN Bus, LonWorks, BACnet, MODBUS-ASCII,
RS-485/RS-422, Ethernet, power line communication and
wireless LAN. CAN Bus was proposed in 1983 in Germany
by Robert Bosch, and the Version 2.0 of CAN Specifications
issued in 1991 is today mostly used in vehicle control
systems and building automation equipment [2].
Application Layer
For the multicasting with Peer to Peer protocol, to identify
the communication between source and destination, the
system needs to have source and destination address in the
packet. For example, if the guard station calls the indoor
machine, the network connector acts like a router. If the
network connector can’t find the destination address in the
routing table, it discards that packet and then sends another
packet to the indoor machine.
For multicasting with Master and Slave protocol there is
one source, but there is a group of destinations for medium
load communication, for example, sending a message for an
Indicator to show the door release.
For broadcasting with Master and Slave protocol there is
one source sending the packet to all devices for high load
communication, for example, the guard station sending an
announcement to all households.
SECURITY OF HOME COMMUNICATION
When the system deals with the communication procedure,
we use the queue or buffer to store the received packets to
prevent the data from being lost. The data transmitted or
received are put in the queue, waiting to be processed. For
example, the system takes an alarm message in the indoor
machine and the message is put in the queue first and then
waits for transmission. Because the alarm message has a
higher priority when the system detects that the medium is
idle, it sends the RTS immediately. Then the system sends an
alarm message or a packet after waiting to receive a CTS.
When the system receives the confirming message, it deletes
the data from the queue.
GUARD AND DOOR STATION
To improve the system performance the central guard
machine is divided into talk-back machine and security
machine. At the door there is the gate machine, used for
video signal, talk-back and entrance lock control. The data
and parameters relating to the gate machine are set up on the
network connectors, and the gate machine calls the indoor
machine or the guard machine by the network connector.
When the design is used for small-scale buildings, just one
button suffices for the indoor machine. But for larger
buildings the design must map the user relations into a twodimensional
array between the logic address and the user
address, as shown in Table VII. The general user address
consists of user number, floor number and room number.