Note: Descriptions are shown in the official language in which they were submitted.
20~8~
The present invention relates to security alarm systems
and in particular, relates to improvements in security alarm
systems suitable for commercial, residential and industrial
use.
The use of security alarm systems is well established
in the art and thus such systems range from very basic units
primarily used in residential applications, to highly complex
systems for relatively large industrial and commercial
applications. ~lthough the capabilities of such systems
varies to a great degree, the basic elements in all systems
remain the same. Thus, a typical system comprises a central
control panel, alarm means, sensors and transmitters.
Although the basic elements remain the same the capability of
these elements will be variable depending upon the particular
requirements. For example, a basic system may include
sensor capabili.ties for one or two parameters while larger
systems may have multiple sensors - i.e. there may be sensors
for theft (glass breakagel forced intrusion, space detection,
etc.) fire and smoke sensors, appliance sensors, temperature
sensors, etc. Basically, each ~ondition to be monitored
utilizes a sensor to de.tect the desired condition or
parameter and a transponder is usually associated with the
sensor for sending the information sensed to the central
control panel~ The sending of the information to the control
panel may either be done through hard wiring or through
wireless means such as radio transmitters.
Aissociated with the alarm systems are means for arming
~ and disarming the system. In a very basic system, such
on/off control may be as basic as means to turn the power on
-- 2
208~6~
and off while todays more sophisticated systems utilize, to
an increasing extent, keypads which are placed at desired
entry locations. The keypad can be used to arm or disarm the
system as well as to program certain information into the
central control panel.
Today, most alarm systems, even in residential
applications, have multiple sensors. With the use o~
multip~e sensors, even for a single function such as
unauthorized entry, it becomes desirable to be able to
identify where the alarm is coming from. ~or example, in a
typical residential/commercial/industrial application, an
alarm system may use a number of sensors on windows and doors
to detect unauthorized entry therein, (this can include both
opening and glass breakage) fire and smokP alarms, moisture
detection, etc. The sounding of an alarm without indicating
the type of problem or area causing the alarm can lead both
to considerable problems in trouble shooting any defective
sensor and/or quickly identifying the source of the alarm for
security purposes. Accordingly, it has now become common
practice for alarms to have a number of different zones, each
zone heing itself able to support several sensors.
In a residential application, a single zone may, ~or example,
include only the bedroom area while another zone would cover
general liviny quarters, another zone would cover the
basement, etc. This wide range of requirements has lead to
the need for most manufacturers to sell a range of alarm
systems 7 ths individual category of the system generally
being characterized by the number of zones which it can
monitor.
208~
Conventional alarm syskems centralize their processing
in the control panel. When utilizing a keypad, the single
step of entering a four digit user code at the keypad would
entail an exchange on the communication BUS. In this
exchanga, the panel queries the keypad, the keypad sends back
the first keystroke, the panel will then either acknowledge
or not acknowledge this keystroke, and the process is
repeated for each of the digits. After entry of, for
example, a four digit user code, the central panel will check
the codes validity and then take the appropriate action. The
central panel would then resume its normal polling of the
transponders.
The entry of the four digit user code re~uires a minimum
of ten data packets on the BUSo At 1200 baud, this requires
approximately 1/lOth of a second. However, if the user
wanted to take some other actions such as clock updates,
changes, modi~ications to user codes, the panel has to buffer
this data until it is complete before anything can be done
since the interaction is in serial fashion. In other words~
although the micro controller has the time to do many other
things, the keypad entry process is inherently a slow one
(being operator controlled) and the micro controller must
wait ~or the data to be completed before it can proceed. If
there is a second keypad, one must allocate twice the buffers
and system resources if th system is to support the second
keypad being accessed at the same time. This in turn,
- quadruples instead of doubles the ~ommunication BUS traffic
since each data packet must contain the address of which
` 208~8~
buffer or keypad it is going to or from. Thus, most
manufacturers are not able to offer a large number of split
armings without extremely expensive ]price tags.
As can be appreciated, the addition of æone expansion
modules to such a BUS could create an unsafe system. Thus,
it would be possihle to compromise such a system by keeping
the panel busy with keypad input/out]put such that the panel
would not be able to discover a system intrusion in a timely
fashion.
A further problem with prior art systems is the number
of peripherals which can be supported by a typical
residential system. Previously, most residential systems
consisted of the central panel and a few transponders.
However, recently greater demands have been placed on the
systems including a number of additional peripherals. This
has led to increased wiring and power loss. In turn, the
potential for greater interference on the line exists thus
causing more false alarms.
It is an object of the present invention to provide an
alarm system which allows for a large number of peripherals.
It is a further object of the present invention to provide an
alarm system wherein the address of the transponder may
easily be set after installation of the system.
It is an object of the present invention to provide an
alarm system which is suitable for use as a basic system and
which can easily be expanded to have far greater
capabilities. It is also an object of the present invention
- to provide an alarm system wherein the control panel cannot
be tied up by the keypad for long periods of time.
208~8~
The present security alarm system is one which can be
used for practically any application ranging from a small
residential application to relatively large commercial
complexes. The advantage of such a system is the
minimization of inventory for the alarm company and the ease
of use for an employee installing the systems since they
would only need to learn one system type. This would in turn
result in fewer faulty installations and fewer false alarms.
For most residential, commercial and industrial
applications, a system having between 4 to 32 zones is
su~ficient with 4 to 16 zones being one of the most popular
system capacities. In the present invention, there is
provided a control panel which has a basic six zone
capability but which can be expanded to be functional up to
96 zones. The present invention provides zone expansion
msdules which can be added on to the basic system as
required, either at the time of installation or as a
subsequent "add on".
The system pre~erably uses a keypad which is provided
with its own micro processor capabilities to minimize the
time factors set forth above. Thus, everything that is
keypad related such as entry of user codes, bypassing,
update, deletion of user codes etc. is done locally at the
keyboards. By so doing, when the user, for example enters
his four digit user code, the keypad will verify the same and
prepares an action code to send to the panel. When the panel
queries the keypad, this is sent to the control panel. For
~ example, in the case of arming the system, when the panel
queries the keypad, the keypad would send the arm co~mand.
` ~)8~6~
The panel would either acknowledge or not acknowledge and
would arm the corresponding area. The keypad would then set
the arm indicator and the panel would continue polling.
Utilizing the above, only three data packets flow on the BUS
for all the keypad functions. No address destination
information is required since all data is prepared with no
waiting for keystrokes and hence one buffer with associated
system resources can accommodate an unlimited number o~
keypads with the only limit being the perceived response time
of the system to the user at the keypad. For example, given
a rate of ~200 baud at three data packets, this equals 27
milli seconds~ Even given 100 keypads placed on the BUS, the
longest wait for a response would be 2.7 secsnds~
Also, most modern alarm systems allow one panel to be
shared among several different users. A problem arises when
a panel i5 "split" because any keypad can be used to
arm/disarm any other split~ This limitation has kept split
systems from being used in installations where high security
is necessary while the present system allows one panel to
protect several different dwellings or offices.
The present invention preferably has both a
microprocessor and non-volatile memory on keypads which
allows them to function independently of the control panel.
The key pads can verify user codes without having to consult
the panel for each
key stroke and thus, the same basic panel can be expanded to
several splits by simply adding more keypads. Isolating the
~ security codes for each split from each other improves the
security thereof.
20~6~
It is also desirable that an alarm system have the
ability to automatically arm/disarm at a given tlme. In
conventional alarm systems, this information was stored in
memory on the control panel and thus only one auto arming or
disarming time can be provided, common to all users and
applicable to all days. The present invention, on the hand,
stores the auto arm/disarm times in the keypad and provides
them with a medium through which to communicate with the
control panel. Thus the system is capable of maintaining
several distinct arm/disarm times for each splik and in
addition, each time may be individually selected or de-
selected for each day of the week.
Conventional alarm panels are responsible for supplying
power to their sensors and peripheral devices. As such, most
alarm panels and sensors operate from a 12 volt supply.
However, this limits the available supply to sensors and also
severely limits the distance which the sensors/transponders
can be located from the control panel. While it is possible
to use a higher battery voltage, this increases cost by
requiring the use of more expensive batteries, larger
transformers and non standard sensors.
The present invention uses a high efficiency step-up
regulator at the panel which changes the transformer voltage
into a higher voltage which is then transmitted to all
peripherals such as keypads and transponders. In turn, these
peripherals have high efficiency step down regulators to
recover th~ lower voltage from which they operate. The
kransponder then can supply sensors with the lower voltage.
208~86~
The arrangement allows longer wire runs to provide a
greater regulation and improves the efficiency of power
distribution. ~lso, one obtains betl:er immunity to induced
electrical noise such as radio transmissions and inductive
motors due to the step down reregulation of the peripheral
power supply while still maintaining high power distribution
efficiency. The system allows the use of standard
peripherals and low cost high resistance wire.
Naturally, alarm systems using transponders require
means of communication between the control panel and the
remote transponders. This communication takes the ~orm of a
voltage or current which is changed between two values, the
pattern of these changes representing the information to be
transmitted. Because it is desirable to have the largest
possible difference between these two voltage levels, most
panels maXa use of their supply, or battery as the upp~r
level while the lower level is set to ground.
The present invention, by using a high voltage
communications BUS through step up regulators to increase the
panel supply voltage and thPn using that increased voltage as
the upper level for communications, allows communication
between panel devices at greater distances. ~lso, noise
immunity is improved by providing for a greater signal swing.
Preferably, the system uses a voltage of above 20 volts
and conveniently may operate at approximately 28 volts.
In alarm systems, the control panel, in order to talk to
one specific device, must assign a unique name or address to
- that device so that it can tell when it is being addressed
and respond accordingly. A traditional method of assigniny
2 ~
these addresses has been by setting a battery of switches on
each device to a unigue combination~ Under such a system,
the installer must first ensure that no two devices have been
given the same combination. This operation is both time
consuming and error prone.
In order to overcome the above, a more recent method
involves first connecting the devices to the control panel.
The control panel then writes the device's address into a
small electronic memory on the device. This avoids having to
set switches on the device, but instead requires the
installer to perform an extra step and to then keep track of
which device is which.
To overcome the above, in a further aspect of this
invention, a module allocation system protocol may be
utilized. In this method, the installer simply wires up the
entire system without regard as to individual device
addresses. Once he has finished wiring th~ system, a control
panel is made operational and the installer will then go from
device to device to ch~ck that each i5 operational. A~ he
checks eaeh device, the installer will either press the
tamper switch or keys in a special code. This will then
cause the control panel to assign a unique and valid address
ko that device over the communications BUS. In other words,
it is only after the system has been installed that the
control panel allocates the individual device addresses.
Having thus generally described the invention,
reference will now be made to the accompanying drawings
- illustrating an embodiment of the invention in whicho
-- 10 --
'2~8~
FIGURE 1 is a block schematic representation of an alarm
system;
FIGURE 2 is a block diagram showing the system
controller and interface therewith;
FIGURE 3 is a block diagram of the keypad and local
announciator;
FIGURE 4 is a block diagram showing a typical
transponder as utilized in the present invention; and
FIGURE 5 is a schematic block diagram of the quick
loader.
Referring to the drawings in greater detail, and by
reference characters thereto, and in particular referring to
Figure 1, there is provided an alarm security system which
includes a central system controller 10. Central system
controller 10 includes interfaces 10 and 12; interface 12 is
a direct interface which is directly wired to sensors 18.
Interface 14 is a communication BUS interface; and example of
such an interface is that known as a "pinpoint" TM interface.
Sensors 22, through remote transponders 20, are connected to
communication BUS interface 14. A keypad 16 also
communicates with the central controller through ~:
communication BUS interface 14. A quick loading means 62 is
also provided for reasons which will be discussed in greater
detail hereinbelow.
Controller 10 includes a microprocessor 30 which is
adapted to monitor sensors 18 and 22. ~hese sensors may
include local and/or remote switch contacts at doors and or
- windows. Other suitable sensors such as motion detectors,
floor mat sensors, fire/smoke detectors, temperature sensors,
-- 11 --
208~86~
etc~ may also be utilized.
Interface 14, as previously mentioned, is also capable
of monitoring and controlling a plurality of remote
transponders 20 via a communications BUS. A number of remote
transponders may be coupled either in serial or parallel
fashion to the interface with the remote transponders/sensors
identifiable either as a particular group or individually.
Central controller 10, in a conventional manner, will
respond to detective states of the alarm sensors by producing
the appropriate alarm signals which in turn will be sent to
suitable alarm devices. The alarm devices may typically
include horns, lights, buzzers, etc. In centrally controlled
systems, the alarm systems may include a telephone dialer
connected to a central switchboard either through a public
telephone network or through direct dedicated communication
media such as direct wire, radio, etc. It will be
understood that the particular response may be partially
determined by the system (factory pre-programed) although
generally, such responses can be modified by the user and/or
installer by suitable programming of the system parameters.
Referring to Figure 2, there is shown a schematic block
diagram of the central controller. It will be understood
that the various circuits and/or functions descrihed herein
are within the capability of those knowledgeable in the art
of designing and thus, are not described in greater detail.
The control includes suitable physical mounting means and
thus, typically the system will include one or more printed
- circuit boards suitably mounted in an enclosure with
appropriate coJmection means provided.
- 12 -
20~8~
Central controller 10 includes a battery 24 to provide
power during any AC power failure so that the ala.m system
will remain functional. Low battery cutoff means 26 are
provided to reduce system maintenance requirements. If,
during an AC power failure, battery 24 should drain below a
prsdetermined point (as determined by voltage divider network
means 28) the system microprocessor 30 will sense this
occurrence and shut off all power to the system except to the
microprocessor itself. This arrangement saves the
battery 24 from discharge dendrite formation which would
otherwise render the battery non rechargeable while, at the
same time, providing the minimal power required for micro
controller 30 so that it can continue to maintain its real
time clock thereby alleviating the system user of the
drudgery of having to reset the clock each time following a
prolonged power ~ailure~ Also, through the ~eedback provided
by the voltage divider network 28, micro controller 30 is
able to monitor the charging voltage on battery 24 and can
switch, if required, to a fast charge circuit 32. As may be
seen from Figure 2, there is also provided power supply
means 33 which are connected to AC supply 31.
Power supply means 33 will include a transformer to
provide a suitable DC voltage normally in the range of 13 to
18 volts. The output to the battery 24 and low battery
cutoff means 26 will be regulated to the desired voltage
which is normally approximately 14 volts. The output to the
system will also be regulated, but at a substantially higher
- voltage - i.e. preferably around 28 volts.
~0~5~6~
Alarm output 34 utilizes a MOSFET power transistor 36
instead of a conventional relay. This permits the use of an
ex~ernal alarm which can either be a bell, which requires a
constant current output, or a siren or other electro
mechanical speaker device to which an audio-wave form must be
supplied. If desired, an output 35 for an automatic
telephone dialer may be provided.
Output connector 38 is provided for all attachable
peripherals such as keypads, transponders, etc. and
communication is provided by means of a 4 wire BUS. As may
be seen from Figure 2, fuse means 40 are provided. A takeoff
monitor 42 feeds a sense transistor 44 so that the system
microprocessor 30 is able to perform automatic diagnosis to
determine if the peripherals are not responding due to lack
of power or otherwise.
An internal emulator circuit 46 allows control of the
direct wire inputs 48. This permits testing during and/or
following manufacturing to provide automatic verification of
the circuit correctness and integrity. Thus, for example, if
there are any poor solder joints or other faults, these can
be tested prior to placing the controller in service. The
system, as illustrated in Figure 2, also includes a
connection point 50 which may be utilized to supervise the
status of the alarm sensors. Connection point 50 can also
function as an additional direct wire input through function
selection circuit 52.
An AC power loss indicator 54 is provided; associated
~ therewith is a 60 hertz pulse source to drive the counter
circuits of the microprocessor 30 for the real time clock.
14 -
. .- - ,
29)~86~
Thus, in the event of AC power failure as would be indicated
by the loss o~ the 60 hertz pulse train, the system
microprocessor 30 has its own crystal frequency source 56 to
generate an appropriate clock signal to keep the real time
clock operational.
Connection point 50 is provided with serial
communication in packet ~raming protocol through drive
circuit 58 while there is provided a buffered reset signal 60
active on power up and during BUS retrys.
Quick loader port 63 is provided for easy access to
system parameter information held in the system EEPRO~ 64 of
microprocessor 30. By utilizing quick loader port 63, the
system can be quickly injected with pertinent system
information to allow immediate and full operation. Thus, the
parameters of a "typical" system can be placed into a
suitable quick loading card and then injected into a virgin
system through quick loader port 63 so that a lot o~ the
lengthy manual programming normally associated with a new
system can be avoided. Quick loader port 63 will also
provide access for testing purposes during the manufacturing
process.
Referring to Figure 3, the circuitry for a typical
keypad 16 is illustrated. It will be understood that this
circuitry would be assembled on a suitable printed circuit
board and housed in a conventional housing which will provide
the required mounting and structural integrity. It will be
- understQod that although the system only demonstrates one
such keypad, a plurality of such keypads may be connected by
20g~6~
means of the 4 wire power, reset and serial packet framing
communications BUS interface 68 to the equivalent BUS
connection 50 in the system controller. The communication
drive circuit 70 is of the open collector type so that no
device can grab and/or hold master control over the BUS
except the circuitry in the system controller location.
Amplification means 72 are provided l:o give local
amplification of the reset signal to alleviate signal
difficulties that may incur in installations with long BUS
lengths. Input through keypad 75 is by matrix arrangement so
that the number of input pins o~ the microprocessor 74 which
are required to achieve the input are kept at a minimum.
In a preferable embodiment, the visual displays are
multiplexed through a single data latch 76 to two seven
segment displays 78A and 78B and to 6 LED's 80 used for
status display. To gate the appropriate data signal from
data latch 76 to the appropriate display, the LED's
se~uentially have power enabled to them through their
respective grounding transistors 82 when the appropriate data
for them is available on a visual data BUS 84. Audible
indications means 86 (local announciator) are provided to~a
speaker 88 mounted integral with the keypad's PCB. Keypad
identification operating parameters are kept in the
micro controllers own dedicated EEPROM 90.
Referring to Figure 4, a typical transponder is
illustrated and will now be referred to. As was the case
with the keypad, the circuitry of transponder 20 is normally
~ mounted on a suitable printed circuit board and placed in a
suitable housing designed to provide the required mounting
- 16 -
208~8~
and structural integrity.
As previously discussed, a plurality of transponders may
ba connected by means of the 4 wire power, raset and serial
packet communications BUS 104 to equivalent BUS connection
point 50 on the system controller. The communication drive
circuit 92 is of the open collector type so that no device
can grasp and hold master control over the BUS. Local
amplification of the reset signal is provided by
amplification means 94 to alleviate signal difficulties that
incur in installations with long BUS lengths.
Each transponder 20 includes a high efficiency switching
regulator means to decrease the voltage to the conventional
level of 12 volts. Each transponder also will have its own
identification number held in the memory of the local
EEPROM 98 of the microprocessor 96.
An internal alarm sensor switch emulator circuit 100
allows control of the direct wire alarm sensor inputs 102
during manufacturing testing to determine if there are any
poor joints or other defects during the assembly process as
well as allowing a test on the inputs of khe micro controller
96. Provision is made to supervise the status of the alarm
sensors through connection point 105 which can also serve as
an additional direct wire input by means of ~unction
selection circuitry 106.
Port 108 is mechanically compatible with the quick
loader port 62 (Figure 2). During installation, the
transponder port 108 is connected to port 62 so that the
- systems microprocessor 30 can have access to the memory of
EEPROM 98 so that the transponders identity numbers can be
æos~s~
automatically programed by th0 system microprocessor 30.
Alternatively, the system can be programed such that the
systems microprocessor 30 can have direct access to EEPROM 98
by means of the four wire BUS. In either way, this speeds
installation time and prevents tampering that would otherwise
be a possibility if the ~ransponders identify codes were
stored locally in the transponder by means such as d.ip
switches.
Thus, the transponder can be provided with a module
allocation system protocol. Upon installation of the system,
the control panel, once operational, will continually address
each device. The installer need only be present at the
transponder and either press the tamper switch or key-in a
special code which will cause the control panel to assign a
unique and valid address to that d~vice over the
communications BUS.
Re~erring to Figure 5, a typical quick loader is shown.
As is the case with the other components, the circuitry is
con~igurated and assembled on a printed circuit board and
housed in a suitable protective material to provide
protection against rough handling and the like.
The quick loader may be connected by means of its own
connector 110 to provide access to the system
microprocessor 30. Power, reset and serial packet framing
communications are equivalent to those that exist on the
communications BUS connection 38 of the central
controller lO. The communication drive circuit 112 is open
~ collector to again prevent any device holding master control
over the BUS. Amplification means 114 provide local
- 18 -
2~8~86~
amplification of the reset signal to alleviate signal loading
of the device. A local microprocessor 116 has access to the
memory of EEPROM 118 so that it can provide the functions of
uploading and downloading stored information into the
EEPROM 64 of microprocessor 30.
It will be understood that the ,above described
embodiments are for purposes of illustration only and that
chanyes and modifications may be made thereto without
departing from the spirit and scope of the invention.
-- 19 --
