Abstract:
When an alarm panel needs to transmit alarm data, it seizes the PSTN and disconnects the premises-wiring. If in a call, the user is cut off immediately and it appears to the user that the connection to the PSTN has been lost. If trying to place a call, the user also perceives that the connection to the PSTN is lost. The present invention provides tonal signals to the user to indicate that the PSTN line is in use by the alarm panel and also notifies the user when the PSTN connection is available for use.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The present application is a continuation of application Ser. No. 10/298,479, filed on Nov. 18, 2002, now U.S. Pat. No. 6,973,165. 

   BACKGROUND OF THE INVENTION 
   The present invention is directed to a wired, alarm control-panel system for protecting a premises site, such that upon the system&#39;s sensing an alarm condition, connection between the premises-wiring and the public switched telephone network, or PSTN, is broken or terminated, and which connection to the PSTN is thereby seized by the alarm control-panel system in order to transmit to, and receive alarm data from, an alarm central station, or the like, over the PSTN. When this alarm condition occurs, any telephone device attached to the premises-wiring is rendered inoperable for the period that the alarm-panel&#39;s PSTN-seizure is in effect. Such seizure of the PSTN and the isolation of the premises-wiring is a considerable problem, especially in time of an emergency. The occupant of the premises, or client, does not know if the disconnected line is due to an alarm seizure by the alarm control-panel system, or due to a break in the connection to the PSTN that was caused by the emergency. In addition, the client does not know when the premises-wiring has been reconnected to the PSTN, so that a telephone call may then be made. 
   Examples of conventional alarm control-panel systems that seize control of the PSTN during an alarm condition for reporting the alarm condition to a central monitoring station, or the like, which seizure also cuts off the premises-wiring from connection to the PSTN is shown in U.S. Pat. No. 4,718,079—Rabito, and U.S. Pat. No. 5,131,019—Sheffer, et al. 
   It would be highly advantageous to provide an alarm control-panel system that monitors a premises for alarm conditions which will notify, warn, or otherwise indicate to the occupant or client of the protected premises when the alarm panel of the alarm control-panel system has seized control of the PSTN-connection, and, also, when the alarm panel has relinquished seizure thereof. This would permit a more reliable use of the premises&#39; telephone devices to make and receive calls, especially in emergency conditions. 
   SUMMARY OF THE INVENTION 
   It is a primary objective of the present invention to provide a signaling system for use with a wired, alarm control-panel systems for protecting a premises site, such that upon the existence of an alarm condition and the subsequent seizure of the PSTN by the alarm control-panel system, the signaling system of the invention signals to the occupant, or client, of the premises such line-seizure of the PSTN, whereby the client will be thus informed. 
   It is also a primary objective of the present invention to provide such a signaling system for use with a wired, alarm control-panel system for protecting a premises site, such that the system of the present invention provides different and unique signaling tones or messaging to the premises-wiring depending upon the state of the alarm control panel and the state of the telephone devices connected to the premises-wiring. 
   Toward these and other ends, the signaling system of the present invention for use with a wired, alarm control-panel system for protecting a premises site is interposed between the protected premises-wiring and the alarm control-panel system, and consists of voltage detectors for monitoring and detecting the status of the premises-wiring connected to the PSTN. The system of the invention also has a PSTN emulator that, during the activated state of the alarm control-panel system, when the PSTN line is seized thereby, will provide central office functionality to the premises-wiring, and, therefore, to the telephone devices connected thereto, in order to provide signal-messaging to the telephone devices during and after the activation of the alarm control-panel system, so that the premises&#39; client is completely informed as to the status of the alarm control-panel system and, also therefore, to the status of the connection to the PSTN. 

   
     BRIEF DESCRIPTION OF THE INVENTION 
     The invention will be more understood with reference to the accompanying, wherein: 
       FIG. 1  is a block diagram of the system of the invention in a condition when the alarm panel has seized control of the PSTN connection, and signaling is produced to a user that such has occurred, and which, upon abandoning of such seizure, will also send out signaling to a user indicating thus; 
       FIG. 2  is a flow chart showing the state of the alarm-panel control system before, during and after an alarm conditional; and 
       FIG. 3  is a flow chart showing the state of the PSTN-emulator of the system of the present invention used in conjunction with the alarm-panel control system before, during and after an alarm condition for indicating to the client when the premises-wiring has been disconnected from the PSTN during line-seizure by the alarm control panel, and when such connection has been restored. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings in greater detail, the total alarm system for a protected site is indicated generally by reference numeral  10 , which system  10  consists of a conventional alarm control-panel apparatus  103 , and the signaling system  100  of the present invention. The signaling system  100  of the present invention is interposed, or electrically coupled, between the alarm control-panel system  103  and a conventional RJ-31X interconnection  104  connecting either premises-wiring  107  or alarm control-panel  103  to the PSTN via control-panel switch  103 ′. 
   The signaling system  100  of the present invention consists of three primary components: A voltage detector  101  that monitors the condition of the PSTN line  109 ; a voltage detector  105  that monitors the condition of the premises-wiring  107 ; and a PSTN emulator  102 , with dedicated microprocessor, that provides the functionality of the PSTN. PSTN emulator preferably provides the following functions: Talk voltage to the premises-wiring, dial tone thereto, ringing thereto, and off-hook detection of devices attached to the premises-wiring. Also included is a switch  102 ′ that allows the premises-wiring to be isolated from alarm control-panel  103 . This switch is in a normally-closed state when no alarm condition is present. 
   When the alarm panel  103  is in its normal “no alarm” state, the switch  103 ′ in the alarm panel is closed, which allows the premises-wiring to be connected to the PSTN. When the alarm panel  103  senses an alarm condition, it opens the switch  103 ′ in order to disconnect the premises-wiring from the PSTN, in order to seize the PSTN line. Once the PSTN line has been seized, the alarm panel  103  goes off-hook in order to transmit alarm data to a central monitoring station. At this time, voltage detector  105  detects no voltage on the premises-wiring  107 , and sends a signal thereof to the microprocessor of the PSTN emulator  102 . The PSTN emulator then checks the status of voltage detector  101  in order to determine if the alarm panel  103  has seized the PSTN line. If voltage detector  101  does not detect voltage on the PSTN line, no further actions occur, since such would indicate that the premises-wiring has been disabled for some reason other than seizure of the PSTN line by the alarm panel  103 . If voltage detector  101  does detect a voltage, such indicates that the alarm panel has seized the PSTN line. The microprocessor of the PSTN emulator  102  will then cause switch  102 ′ to open, thereby preventing accidental application of the talk battery voltage from the PSTN line to the premises-wiring and to the PSTN emulator if the alarm panel switch  103 ′ closes unexpectedly, thereby providing protection thereto. With switch  102 ′ open, the microprocessor of the PSTN emulator will cause talk battery voltage to be supplied to the premises-wiring  107 . At this juncture, it will monitor the premises-wiring for an off-hook condition by one of the telephone devices connected to the premises-wiring. If an off-hook condition is detected, the microprocessor of the PSTN emulator will cause the application of distinctive signaling, such as a warbling dial tone or a series of individual tones, to the premises-wiring, and, therefore, to any telephone device connected thereto. These distinctive tones alert the user of the telephone device that the alarm panel has seized control of the PSTN line, and that an alarm state exists at his premises, and that outgoing or incoming calls are not possible at that time. It is, of course, to be understood that the specific distinctive tone-signaling that is generated may be changed as will be apparent to one of ordinary skill in the art. 
   When voltage detector  105  again detects voltage on the wiring  108  from the alarm panel, it sends a signal to the microprocessor of the PSTN Emulator  102 . The microprocessor of the PSTN emulator will then cause a different distinctive signal to be sent to the premises-wiring. The type of signal will depend if a telephone device on the premises-wiring is on-hook or off-hook. For example, if a telephone device is detected as off-hook at this time, different dial-tone signaling is generated. If on-hook, a distinctive ring signal will be generated. It is, of course, to be understood that the specific distinctive tone-signaling that is generated for each state may be changed as will be apparent to one of ordinary skill in the art. This signal will notify the user that the alarm panel  103  has relinquished its control of the PSTN line  109 . After generating the distinctive signal, the PSTN emulator will remove the talk battery voltage and close switch  102 ′. The PSTN wiring is now connected to the premises-wiring, and the telephone devices connected can operate in a normal fashion. 
   Referring now to  FIG. 2 , there is shown the flow chart for the alarm-panel process (block  110 ). The microprocessor of the alarm control-panel apparatus continuously monitors the protected site or premises for an alarm state (block  112 ). If no alarm condition is sensed, the alarm control-panel apparatus is disconnected from the PSTN (block  114 ), by switch  103 ′ being kept closed (block  116 ), with switch  102 ′ of the PSTN emulator also being kept closed by the PSTN emulator (see  FIG. 3 ). If an alarm-condition is detected, then the microprocessor of the alarm control-panel apparatus opens switch  103 ′ in order to disconnect the premises-wiring from the PSTN in order to seize the PSTN line (block  118 ), and then transmits the alarm-message over the PSTN (block  120 ). The software associated with the microprocessor of the alarm control-panel apparatus then checks to see the alarm-message transmission has been completed (block  122 ). If “NO”, then switch  103 ′ is retained in its open state (block  124 ). If “YES”, then the software causes the closure of the switch  103 ′ to return the PSTN connection to the premises-wiring (block  126 ), with the system returning to its alarm-condition monitoring mode (block  110 ). 
   Referring now to  FIG. 3 , there is shown the flow chart for the PSTN emulator apparatus (block  130 ). The microprocessor continuously monitors the state of the voltage detector  105  (block  132 ) in order to determine if the premises-wiring is connected to PSTN. If no voltage is detected, which is a “YES” to decision block  132 , then the software for the microprocessor of the PSTN emulator first causes the checking of the condition of the voltage detector  101  (block  134 ). If no voltage is detected, which is a “NO” to decision block  134 , then no action is taken since such indicates that the alarm panel has not seized the PSTN line, and is not transmitting alarm-messages to a central station (block  136 ). This would indicate that there is line-trouble associated with the PSTN. Alternatively, for those alarm control panels that have as one alarm-condition input the outage of the PSTN line as determined by a line-fault detector, which may occur due a line-cut by a burglar, the alarm control panel will send out its alarm-message data via a back-up radio link, as in well-known in the art. If PSTN voltage is detected by the voltage detector  101 , which is a “YES” to decision block  134 , then the microprocessor of the PSTN emulator will open switch  102 ′, in order to isolate the premises-wiring and the voltage-sensitive hardware of the PSTN emulator (block  138 ) as described above. At this point, the microprocessor of the PSTN emulator will control the hardware components thereof, and initiate talk-voltage to the premises-wiring (block  140 — FIG. 3B ), so that the telephone devices connected to the premises-wiring are activated. As long as the PSTN line remains disconnected from the premises-wiring, this talk-voltage is supplied to the premises-wiring. The microprocessor of the PSTN emulator also control the hardware components thereof associated with the generation of one or more distinct tone-signaling for the telephone devices connected to the premises-wiring. These one or more distinct tone-signaling for the telephone devices are used to signal the status of the alarm control panel&#39;s connection to the PSTN. The first distinct tone-signaling is for the off-hook state of the telephone devices connected to the premises-wiring. If, while the alarm control panel is connected to the PSTN, a telephone device goes off-hook (which is “YES” to the decision block  142 ), then the microprocessor will detect such and cause the generation of these first distinct tones (block  144 ),  50  that the user, or client, will be informed that his premises is in an “alarm-present” state. 
   After the alarm control panel has completed transmitting its alarm-message data, the switch  103 ′ thereof will again be closed, in order to reconnect the premises-wiring to the PSTN, as described above with reference to  FIG. 2 . This state causes the voltage detector  105  to again sense voltage (“NO” to decision block  132 — FIG. 3A ). The software determines if the PSTN emulator switch  102 ′ is open or closed (block  146 ). If the answer is “NO”, which is state after the alarm control panel has completed alarm-message transmission and has terminated its seizure of the PSTN line, then the microprocessor of the PSTN emulator receives the signal (block  148 ), and then is ready to generate appropriate tone-signaling indicative of the state of end of PSTN line-seizure by the alarm control panel. The software then determines if a telephone device connected to the premises-wiring is off-hook, or not (decision block  150 ). If the answer “YES”, then a distinctive tone will be generated, which is different from the alarm-panel line-seizure tones generated during block  144 , in order to indicate to the client at the premises that the alarm-transmission has terminated, and that the premises-wiring is about to be reconnected to the PSTN line (block  152 ). If the answer to decision block  150  is “NO”, meaning that no off-hook was detected, then the microprocessor will cause different distinct tones to be generated (block  154 ), such as distinctive ring tones, in order to indicate the client at the premises that the PSTN line seizure has terminated. After the line-seizure termination tones have been generated, the microprocessor causes the switch  102 ′ to return to its normally closed position, whereupon the premises-wiring is again connected to the PSTN (block  156 ), whereupon the PSTN emulator system returns to its steady-state status (“YES” to decision block  146 ). 
   The hardware used by the PSTN emulator  100  for providing central office (CO) functions to the premises-wiring is well-known and conventional, and includes a talk-voltage battery supply, ring-tone generators, a dial-tone generator, and the like, depending upon which distinctive tone-signaling is to be associated with the above-described, unique events for indicating the status of PSTN line-seizure or the lack thereof. Such hardware for providing CO functions to a premises-wiring is disclosed, for example, in commonly-owned U.S. Pat. Nos. 5,715,296; 5,812,643; and 5,946,616. 
   While a specific embodiment of the invention has been shown and described, it is to be understood that numerous changes and modifications may be made therein without departing from the scope and spirit of the invention as set forth in the appended claims.