CA2207498C - Alarm panel protocol converter - Google Patents
Alarm panel protocol converter Download PDFInfo
- Publication number
- CA2207498C CA2207498C CA 2207498 CA2207498A CA2207498C CA 2207498 C CA2207498 C CA 2207498C CA 2207498 CA2207498 CA 2207498 CA 2207498 A CA2207498 A CA 2207498A CA 2207498 C CA2207498 C CA 2207498C
- Authority
- CA
- Canada
- Prior art keywords
- protocol
- converter
- alarm panel
- dvac
- frequency based
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/04—Telephonic communication systems specially adapted for combination with other electrical systems with alarm systems, e.g. fire, police or burglar alarm systems
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B25/00—Alarm systems in which the location of the alarm condition is signalled to a central station, e.g. fire or police telegraphic systems
- G08B25/14—Central alarm receiver or annunciator arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Alarm Systems (AREA)
- Communication Control (AREA)
Abstract
A converter provides an intermediary for allowing an alarm panel designed to use a first protocol to interact with a remote scanner using a second protocol. The converter to the alarm panel is a remote receiver and thus the function of the alarm panel remains unchanged. The converter to the remote scanner is an alarm panel. The converter, in essence, has two receivers and two transmitters and a conversion table for converting system status signals from one protocol to a second protcol.
Description
TITLE: ALARM PANEL PROTOCOL CONVERTER
FIELD OF THE INVENTION
The present invention relates to an alarm panel circuit connected to an alarm panel providing a signal conversion arrangement allowing communications between an alarm panel using one communications protocol and a receiver using a different protocol.
BACKGROUND OF THE INVENTION
Generally, alarm panel systems detect and announce various conditions, such as a motion sensed, glass broken, or a door opened for the monitored premises. Some security applications require a high degree of security and sophisticated alarm panels communicate the system state via specialized dedicated comml]n;cation lines to a receiver located at the initial switching station. These panels are ~hard-wired~ to the receivers. Typically, a receiver is connected to a number of alarm panels and sequentially polls each panel for their status. In response, each panel will reply with a message indicating either that there are no alarm conditions or that a sensor (or sensors) connected to the panel is reporting an alarm condition or other condition.
A receiver must meet m;niml]m statistical standards to obtain certification. Therefore, a receiver must be able to answer calls from any of its connected alarm panels with a m;n;ml]m statistical degree of certainty. To achieve this statistical certainty, dedicated data links between alarm panels and a receiver may be used. The statistical certainty of such a configuration is primarily based on the communications traffic density of the data links.
CA 02207498 l997-06-lO
In Canada, the telephone company provides dedicated data links connecting individual alarm panels to a receiver at the telephone switching station. The receiver and the alarm panels communicate with the receiver using a data link protocol known as Digital Voice Access Service (DVAC).
This arrangement requires a new line being provided for each installation and is quite expensive to install and maintain.
An alarm system can use conventional telephone lines as a communications link between alarm panels and the receiver but this is considered less secure and would require new alarm panels.
There are many existing alarm panels which use the DVAC protocol and these alarm panels typically are associated with a sophisticated group of sensors. This further complicates any changes which involve replacing the alarm panel. Frequency based protocols have been developed which enable communications between the alarm panel and the receiver over the telephone network whether or not the line is already seized. For applications requiring a higher degree of security, a dedicated telephone line can be provided. With a dedicated telephone line, the response time is faster and security is improved. With a dedicated telephone line, the security system is statistically deterministic, like alarm panel systems using dedicated data links. One particular protocol uses Frequency Shift Keyed ("FSK") tones; another protocol uses an encoded "spread spectrum" protocol which disperses the content of the message through a range of frequencies; another protocol uses a series of low frequency signals. Signals coded using these frequency based protocols are generally not audible to the telephone users or non intrusive.
Unfortunately, alarm panels using the DVAC protocol cannot use the standard telephone lines and a frequency based communications protocol. Wiring complications make installation of a new alarm panel impractical. As such, alarm panels which use a dedicated data link and a data link are difficult to convert to a system using the telephone network and a frequency based protocol.
The present invention overcomes these limitations by providing an alarm panel conversion unit which converts signals from a data link protocol to a frequency based protocol for the telephone network and vice versa. A
frequency based protocol receiver is located at the telephone switching station.
As such, the panel conversion unit provides an alarm panel conversation circuit. All signals from the alarm panel are received by the conversion unit using the DVAC protocol. The unit provides the appropriate DVAC
signals to the alarm panel. The alarm panel communicates solely with the conversion unit. The conversion unit produces the query signals sent to the alarm panel and receives the response signals from the alarm panel. The conversion unit extracts information of the status of the system from the responses and generates a frequency based protocol alarm panel status signals. Finally, when the frequency based protocol receiver queries the conversion unit, the conversion unit sends the frequency based protocol status message over the telephone network to the receiver.
SUMMARY OF THE INVENTION
A converter for an alarm panel according to the present invention comprises a first receiver and transmitter for connecting to an alarm panel and comml]n;cate therewith according to a DVAC protocol for extracting alarm system status signals, a conversion arrangement for converting alarm system status signals from a DVAC protocol to a frequency based protocol, and a second receiver and transmitter for communicatin~ over a telephone CA 02207498 l997-06-lO
system with a receiver using a frequency based telephone protocol.
According to an aspect of the invention, the first receiver and transmitter sends a DVAC query signal on a predetermined basis.
According to a further aspect of the invention, the conversion arrangement includes a look up table of DVAC
alarm panel signals and corresponding frequency based signals which is used to convert system status signals from DVAC protocol to frequency based protocol.
According to an aspect of the invention, the converter uses a spread spectrum protocol, a frequency shift key protocol or a low frequency based protocol.
The present invention is also directed to the combination which includes an alarm panel which transmits status signals using a DVAC protocol and processes received DVAC protocol signals, a converter immediately adjacent said alarm panel which receives the alarm panel status signals and converts the status signals to an equivalent frequency based protocol status signal and provides a suitable DVAC response signal to the alarm panel. The converter further includes a second receiver and transmitter for communicating over a telephone system with a remote receiver connected thereto by the telephone system. The second receiver uses a frequency based telephone protocol to report the alarm panel status when a query signal is received from said remote receiver.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the invention are shown in the drawings, wherein:
CA 02207498 l997-06-lO
Figure 1 is a schematic of a prior art security system including a central panel utilizing a data connection to the telephone office;
Figure 2 is a schematic of a security alarm panel of the present invention including a DVAC alarm panel connected to a converter for DVAC and frequency based protocol signals, and a connection to a frequency based protocol scanner at the telephone office; and Figure 3 is an expanded schematic of the present invention and the communication arrangement of an alarm panel.
DETAILED DESCRIPTION OF THE DRAWINGS
Figure 1 shows details of a prior art panel system 1 using a DVAC comml]n;cations system. Sensors 3 are connected to DVAC alarm panel 2. Alarm panel 2 is connected to DVAC modem 4 through Tx data and Rx data F1 and F2 subsets 5 and 6 respectively. Modem 4 is connected through a dedicated telephone data connection 7 to DVAC
receiver 8, located at the Telephone Switching Office 10.
The DVAC communications system operates as follows.
The state of all sensors are detected by alarm panel 2.
Meanwhile, receiver 8 intermittently polls alarm panel 2 for the status of sensors 3 through data connection 7, DVAC
modem 4 and terminals F1 and F2. Typically, alarm panel 2 is polled two or three times every minute. In response to each polling, alarm panel 2 sends a DVAC signal through Tx data and Rx data terminals indicating the status of the sensors. Receiver 8 accepts and interprets any and all responses received from alarm panel 2 on line 7. If a response indicates an alarm condition, receiver 8 notifies the central security office through switch 9. If the alarm panel fails to respond to a query, this provides an indication that an alarm condition exists.
WH-9~lOCA
Figure 2 shows details of the present invention wherein modem 4 and receiver 8 of Figure 1 are replaced by a signal converter 18 and frequency based protocol scanner 23, respectively. The invention operates as follows.
Sensors 17 are connected to alarm panel 16. Converter 18 intermittently polls alarm panel 16 through Tx data and Rx data terminals using the DVAC protocol. The rate of polling used by the converter 18 can be several times more frequent than the typical polling rate used by a DVAC receiver, as the converter is only polling a single panel. In response to each polling, alarm panel 16 sends a DVAC signal through Tx data and Rx data indicating the status of the sensors.
All signals between alarm panel 16 and converter 18 are DVAC signals. The alarm panel 16 continues in its normal operation and is merely polled more frequently by the converter 18. Therefore the alarm panel 16 and the sensors 17 remain unchanged but now essentially report to converter 18.
Scanner 23 periodically queries converter 18 for the status of the alarm system. All commllnl cations between scanner 23 and converter 18 uses a frequency based protocol. Converter 18 receives and converts the status of the alarm panel 16 for reporting to scanner 23 when scanner 23 polls the converter or otherwise requires converter 18 to report. In this way, the converter acts as an intermediary and provides appropriate translation to allow DVAC control panel 16 to report to scanner 23 using a frequency protocol and telephone line 21 and without the specialized date link 7 of Figure 1.
Converter 18 to scanner 23 appears to be an alarm panel which uses a frequency based protocol. Converter 18 to alarm panel 16 appears to be a scanner which uses the DVAC protocol.
Figure 3 shows aspects of the converter 34.
Converter 34 contains microprocessor 35 and Digital Signal Processor (DSP) 36. Microprocessor 35 is the main CA 02207498 l997-06-lO
controlling unit of converter 34. In response to a polling signal sent by the converter to the alarm panel, the converter receives system status signals. These signals are processed by microprocessor 35. It extracts the system status information received in the signals from the alarm panel and then accesses protocol look-up table 38 to select an equivalent frequency based protocol system status signal. Finally, when scanner 39 sends a query to microprocessor 35, DSP 36 generates and sends an equivalent frequency based protocol system status signal to scanner 39.
With this arrangement, existing alarm panels which operate using the DVAC protocol are maintained thereby avoiding costly rewiring. The alarm panel now reports to a converter located on the premise over its own data link.
The frequency of polling is increased. The converter receives and processes signals received from the alarm panel and converts the signals into an equivalent frequency based signal. This equivalent signal indicating the present status of the alarm system is provided to the scanner in response to a query signal provided over a telephone line. The security level of the system is maintained while the costs for the communication link has been reduced.
The frequency based protocol includes spread spectrum protocol and frequency shift key protocol as two examples. The frequency range is preferrably in the range of 20 hz to 6000 hz.
From the above, it can be appreciated that the converter can be modified to report in any desired manner or protocol to a remote scanner. The alarm panel continues to function as if its operation has not changed.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
FIELD OF THE INVENTION
The present invention relates to an alarm panel circuit connected to an alarm panel providing a signal conversion arrangement allowing communications between an alarm panel using one communications protocol and a receiver using a different protocol.
BACKGROUND OF THE INVENTION
Generally, alarm panel systems detect and announce various conditions, such as a motion sensed, glass broken, or a door opened for the monitored premises. Some security applications require a high degree of security and sophisticated alarm panels communicate the system state via specialized dedicated comml]n;cation lines to a receiver located at the initial switching station. These panels are ~hard-wired~ to the receivers. Typically, a receiver is connected to a number of alarm panels and sequentially polls each panel for their status. In response, each panel will reply with a message indicating either that there are no alarm conditions or that a sensor (or sensors) connected to the panel is reporting an alarm condition or other condition.
A receiver must meet m;niml]m statistical standards to obtain certification. Therefore, a receiver must be able to answer calls from any of its connected alarm panels with a m;n;ml]m statistical degree of certainty. To achieve this statistical certainty, dedicated data links between alarm panels and a receiver may be used. The statistical certainty of such a configuration is primarily based on the communications traffic density of the data links.
CA 02207498 l997-06-lO
In Canada, the telephone company provides dedicated data links connecting individual alarm panels to a receiver at the telephone switching station. The receiver and the alarm panels communicate with the receiver using a data link protocol known as Digital Voice Access Service (DVAC).
This arrangement requires a new line being provided for each installation and is quite expensive to install and maintain.
An alarm system can use conventional telephone lines as a communications link between alarm panels and the receiver but this is considered less secure and would require new alarm panels.
There are many existing alarm panels which use the DVAC protocol and these alarm panels typically are associated with a sophisticated group of sensors. This further complicates any changes which involve replacing the alarm panel. Frequency based protocols have been developed which enable communications between the alarm panel and the receiver over the telephone network whether or not the line is already seized. For applications requiring a higher degree of security, a dedicated telephone line can be provided. With a dedicated telephone line, the response time is faster and security is improved. With a dedicated telephone line, the security system is statistically deterministic, like alarm panel systems using dedicated data links. One particular protocol uses Frequency Shift Keyed ("FSK") tones; another protocol uses an encoded "spread spectrum" protocol which disperses the content of the message through a range of frequencies; another protocol uses a series of low frequency signals. Signals coded using these frequency based protocols are generally not audible to the telephone users or non intrusive.
Unfortunately, alarm panels using the DVAC protocol cannot use the standard telephone lines and a frequency based communications protocol. Wiring complications make installation of a new alarm panel impractical. As such, alarm panels which use a dedicated data link and a data link are difficult to convert to a system using the telephone network and a frequency based protocol.
The present invention overcomes these limitations by providing an alarm panel conversion unit which converts signals from a data link protocol to a frequency based protocol for the telephone network and vice versa. A
frequency based protocol receiver is located at the telephone switching station.
As such, the panel conversion unit provides an alarm panel conversation circuit. All signals from the alarm panel are received by the conversion unit using the DVAC protocol. The unit provides the appropriate DVAC
signals to the alarm panel. The alarm panel communicates solely with the conversion unit. The conversion unit produces the query signals sent to the alarm panel and receives the response signals from the alarm panel. The conversion unit extracts information of the status of the system from the responses and generates a frequency based protocol alarm panel status signals. Finally, when the frequency based protocol receiver queries the conversion unit, the conversion unit sends the frequency based protocol status message over the telephone network to the receiver.
SUMMARY OF THE INVENTION
A converter for an alarm panel according to the present invention comprises a first receiver and transmitter for connecting to an alarm panel and comml]n;cate therewith according to a DVAC protocol for extracting alarm system status signals, a conversion arrangement for converting alarm system status signals from a DVAC protocol to a frequency based protocol, and a second receiver and transmitter for communicatin~ over a telephone CA 02207498 l997-06-lO
system with a receiver using a frequency based telephone protocol.
According to an aspect of the invention, the first receiver and transmitter sends a DVAC query signal on a predetermined basis.
According to a further aspect of the invention, the conversion arrangement includes a look up table of DVAC
alarm panel signals and corresponding frequency based signals which is used to convert system status signals from DVAC protocol to frequency based protocol.
According to an aspect of the invention, the converter uses a spread spectrum protocol, a frequency shift key protocol or a low frequency based protocol.
The present invention is also directed to the combination which includes an alarm panel which transmits status signals using a DVAC protocol and processes received DVAC protocol signals, a converter immediately adjacent said alarm panel which receives the alarm panel status signals and converts the status signals to an equivalent frequency based protocol status signal and provides a suitable DVAC response signal to the alarm panel. The converter further includes a second receiver and transmitter for communicating over a telephone system with a remote receiver connected thereto by the telephone system. The second receiver uses a frequency based telephone protocol to report the alarm panel status when a query signal is received from said remote receiver.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the invention are shown in the drawings, wherein:
CA 02207498 l997-06-lO
Figure 1 is a schematic of a prior art security system including a central panel utilizing a data connection to the telephone office;
Figure 2 is a schematic of a security alarm panel of the present invention including a DVAC alarm panel connected to a converter for DVAC and frequency based protocol signals, and a connection to a frequency based protocol scanner at the telephone office; and Figure 3 is an expanded schematic of the present invention and the communication arrangement of an alarm panel.
DETAILED DESCRIPTION OF THE DRAWINGS
Figure 1 shows details of a prior art panel system 1 using a DVAC comml]n;cations system. Sensors 3 are connected to DVAC alarm panel 2. Alarm panel 2 is connected to DVAC modem 4 through Tx data and Rx data F1 and F2 subsets 5 and 6 respectively. Modem 4 is connected through a dedicated telephone data connection 7 to DVAC
receiver 8, located at the Telephone Switching Office 10.
The DVAC communications system operates as follows.
The state of all sensors are detected by alarm panel 2.
Meanwhile, receiver 8 intermittently polls alarm panel 2 for the status of sensors 3 through data connection 7, DVAC
modem 4 and terminals F1 and F2. Typically, alarm panel 2 is polled two or three times every minute. In response to each polling, alarm panel 2 sends a DVAC signal through Tx data and Rx data terminals indicating the status of the sensors. Receiver 8 accepts and interprets any and all responses received from alarm panel 2 on line 7. If a response indicates an alarm condition, receiver 8 notifies the central security office through switch 9. If the alarm panel fails to respond to a query, this provides an indication that an alarm condition exists.
WH-9~lOCA
Figure 2 shows details of the present invention wherein modem 4 and receiver 8 of Figure 1 are replaced by a signal converter 18 and frequency based protocol scanner 23, respectively. The invention operates as follows.
Sensors 17 are connected to alarm panel 16. Converter 18 intermittently polls alarm panel 16 through Tx data and Rx data terminals using the DVAC protocol. The rate of polling used by the converter 18 can be several times more frequent than the typical polling rate used by a DVAC receiver, as the converter is only polling a single panel. In response to each polling, alarm panel 16 sends a DVAC signal through Tx data and Rx data indicating the status of the sensors.
All signals between alarm panel 16 and converter 18 are DVAC signals. The alarm panel 16 continues in its normal operation and is merely polled more frequently by the converter 18. Therefore the alarm panel 16 and the sensors 17 remain unchanged but now essentially report to converter 18.
Scanner 23 periodically queries converter 18 for the status of the alarm system. All commllnl cations between scanner 23 and converter 18 uses a frequency based protocol. Converter 18 receives and converts the status of the alarm panel 16 for reporting to scanner 23 when scanner 23 polls the converter or otherwise requires converter 18 to report. In this way, the converter acts as an intermediary and provides appropriate translation to allow DVAC control panel 16 to report to scanner 23 using a frequency protocol and telephone line 21 and without the specialized date link 7 of Figure 1.
Converter 18 to scanner 23 appears to be an alarm panel which uses a frequency based protocol. Converter 18 to alarm panel 16 appears to be a scanner which uses the DVAC protocol.
Figure 3 shows aspects of the converter 34.
Converter 34 contains microprocessor 35 and Digital Signal Processor (DSP) 36. Microprocessor 35 is the main CA 02207498 l997-06-lO
controlling unit of converter 34. In response to a polling signal sent by the converter to the alarm panel, the converter receives system status signals. These signals are processed by microprocessor 35. It extracts the system status information received in the signals from the alarm panel and then accesses protocol look-up table 38 to select an equivalent frequency based protocol system status signal. Finally, when scanner 39 sends a query to microprocessor 35, DSP 36 generates and sends an equivalent frequency based protocol system status signal to scanner 39.
With this arrangement, existing alarm panels which operate using the DVAC protocol are maintained thereby avoiding costly rewiring. The alarm panel now reports to a converter located on the premise over its own data link.
The frequency of polling is increased. The converter receives and processes signals received from the alarm panel and converts the signals into an equivalent frequency based signal. This equivalent signal indicating the present status of the alarm system is provided to the scanner in response to a query signal provided over a telephone line. The security level of the system is maintained while the costs for the communication link has been reduced.
The frequency based protocol includes spread spectrum protocol and frequency shift key protocol as two examples. The frequency range is preferrably in the range of 20 hz to 6000 hz.
From the above, it can be appreciated that the converter can be modified to report in any desired manner or protocol to a remote scanner. The alarm panel continues to function as if its operation has not changed.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
Claims (7)
1. A converter for an alarm panel, said converter comprising a first receiver and transmitter for connecting to an alarm panel and communicate therewith according to a DVAC protocol for extracting alarm system status signals, a conversion arrangement for converting said alarm system status signals from a DVAC protocol to a frequency based protocol, and a second receiver and transmitter for communicating over a telephone system with a receiver using a frequency based telephone protocol.
2. A converter as claimed in claim 1 wherein said first receiver and transmitter sends a DVAC query signal on a predetermined basis.
3. A converter as claimed in claim 2 wherein said conversion arrangement includes a look up table of DVAC
alarm panel signals and corresponding frequency based signals which is used to convert system status signals from DVAC protocol to frequency based protocol.
alarm panel signals and corresponding frequency based signals which is used to convert system status signals from DVAC protocol to frequency based protocol.
4. A converter as claimed in claim 3 wherein said frequency based protocol is a spread spectrum protocol.
5. A converter as claimed in claim 3 wherein said frequency based protocol is a frequency shift key protocol.
6. A converter as claimed in claim 3 wherein said frequency based protocol is a frequency based protocol within the range of 20 to 6000 hz.
7. In combination an alarm panel which transmits status signals using a DVAC protocol and processes received DVAC protocol signals, a converter immediately adjacent said alarm panel which receives said alarm panel status signals and converts said status signals to an equivalent frequency based protocol status signal and provides a suitable DVAC response signal to said alarm panel, said converter further including a second receiver and transmitter for communicating over a telephone system with a remote receiver connected thereto by said telephone system, said second receiver using a frequency based telephone protocol to report said alarm panel status when a status signal is received from said remote receiver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2207498 CA2207498C (en) | 1997-06-10 | 1997-06-10 | Alarm panel protocol converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2207498 CA2207498C (en) | 1997-06-10 | 1997-06-10 | Alarm panel protocol converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2207498A1 CA2207498A1 (en) | 1998-12-10 |
| CA2207498C true CA2207498C (en) | 2001-12-18 |
Family
ID=4160862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2207498 Expired - Lifetime CA2207498C (en) | 1997-06-10 | 1997-06-10 | Alarm panel protocol converter |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2207498C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE0002981D0 (en) * | 2000-08-22 | 2000-08-22 | Mobile Notifier Ab | Device for remotely transmitting alarms |
-
1997
- 1997-06-10 CA CA 2207498 patent/CA2207498C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2207498A1 (en) | 1998-12-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20170612 |