GB2049359A - Telephone alarm transmitter - Google Patents

Abstract

The present invention relates to apparatus for transmitting an alarm condition, following the occurrence of a state of alarm, by automatically dialling prestored telephone numbers and by the automatic transmission of an alarm message upon receipt of a response to said dialling. The transmitter is used in conjunction with telephones, the numbers of which are pre-stored for dialing, which have a teleprinter connected to them via a MODEM. The transmitted message, coded to meet requirements of the telephone network being used, is such that a readily intelligible message is printed on a teleprinter connected to a responding telephone. The transmitter may be so constructed that the stored telephone numbers as well as other information relating to the content of the message and/or the specific operating procedures of the transmitter may be modified via a MODEM connected to one of the telephones which can be dialled by the transmitter.

Description

SPECIFICATION Telephone alarm transmitter The present invention relates to apparatus for transmitting an alarm condition by automatically dialling telephone numbers and by the automatictransmis- sion of messages over the network connected between the monitored site at which the transmitter is located and the subscriber called automatically by the transmitter.

In known apparatus of this type, the messages transmitted during a state of alarm are recorded on a magnetic tape in speech. Such apparatus has the drawback of requiring mechanical devices for driving the tape which may jam and require considerable expenditure if a high degree of reliability is desired. With apparatus of this type there is no written record of the state of the alarm, unless the operator called by the transmitter makes a manual transcription.

Transmitters are also known in which the message is coded in the form of pulse sequences at vocal frequencies requiring the subscriber called to be in possession of specific, complicated and costly decoding equipment.

In the case of known automatic transmitters, the first programming or storage of the modification of the telephone numbers to be called requires the programming of a read-only memory, by means of a magnetic or optical support device, or by bootstrap or hard wired coding; the programming operation is therefore difficult, costly and requires specific programming equipment.

With a view to mitigating the above mentioned drawbacks the present invention provides a telephone alarm transmitter for automatically dialling pre-stored telephone numbers following the occurrance of a state of alarm, each telephone, the number of which is pre-stored, being connected to a teleprinter via a MODEM, comprising means for transmitting messages, coded to the modulator standards of the telephone network to which the means are connected, such that a readily intelligible alarm message is automatically printed on the teleprinter connected to a telephone which responds to said dialling.

Preferably, the message transmitted in case of alarm is recorded in a readily intelligible form atthe receiving end by a standard teleprinter connected to the telephone via a standard modulator/demodulator (MODEM). The message transmitted may contain not only the call origin but also other data of interest to the monitor called: information concerning the sensor which has triggered the alarm, the time lapse since the triggering of the alarm etc.

The programming of the parameters of each transmitter (for example, telephone numbers to be called, call origin, time lapse before triggering of a local alarm) may be carried out by remote control via the connected telephone network and by means of the keyboard teleprinter installed at the monitor's site. Consequently with the same equipment (keyboard teleprinter, MODEM), the monitor may both receive the alarm message and programme further transmitters, or modify, if necessary, parameters of the installed transmitters. This feature of the invention simplifies the programming operation and reduces its cost.

Preferably, the transmitter of the invention may operate in accordance with two different cycles. The algorithms of the 2 cycles are stored in a monolithic read-only memory and are executed by a monolithic microprocessor. The first cycle is in the alarm cycle; it is triggered on the physical occurence of a state of alarm (for example, the breakage of a loop through which a current passes). The transmitter performs a control function, if its non-volatile memory, in which its operating parameters are stored, is in a suitably programmed state; this control is carried out by means of redundant words written in the memory at the end of a programming cycle (see below). If the non-volatile memory is not correctly signed (the case of a virgin transmitter), it will trigger a local alarm if the monitored site is equipped with one.In these circumstances the transmitter does not, in effect, have available the telephone numbers to be called. If the volatile memory is correctly signed, the transmitter will call the subscribers whose telephone numbers are recorded in a list in the non-volatile memory. As soon as the subscriber called has lifted the receiver, the transmitter, identifying the carrier frequency of the MODEM at the other end of the line, transmits its message modulated in accordance with the MODEM protocols. It will then wait for a conformation signal corresponding to the operation of keys on the keyboard of the subscriber called; when the conformation signal is received, the transmitter has terminated its alarm cycle.If the subscribers do not reply, or if the transmitter does not obtain a conformation signal for its messages, it calls the other subscribers from the list of numbers programmed in its non-volatile memory going through the list in a circular manner.

If the transmitter has still not received a reply or a confirmation signal within the time programmed during a programming cycle, see below, it triggers a local alarm if the monitored site is equipped with one, and continues to call the programmed subscribers in rotation until it obtains a confirmation signal, or until the termination of a total action time which is also programmed during a programming cycle.

The second cycle in which the transmitter of the invention may preferably operate is the programming cycle.

This cycle is triggered following a manual action on a key of the transmitter, informing the transmitter that programming is required. ltthen engages the telephone line and holds a dialogue with the subscriber at the other end of the line by means of the keyboard teleprinter and the MODEM; the dialogue is in the form of questions set by the transmitter and displayed on the operator's teleprinter, and responses typed by the operator on his keyboard which are analyzed and stored by the transmitter in its non-volatile memory. If the operator types a syntactical or sematic error, the transmitter repeats its questions until it receives a correct reply.

The programming cycle is terminated when the transmitter has received all the parameters correctly and it is waiting for a particular command type by the operator signifying that the transmitter should terminate the call. It will then add redundant words to its non-volatile memory so that during an alarm cycle (see above) it will be able to ascertain that its memory is correctly programmed, and then it terminates its cycle. If should be noted that the programming cycles may be repeated indefinitely each time it is necessary to modify all or part of the parameters of the transmitter.

The present invention will now be described by way of example and with reference to the accompanying single figure of drawing which shows one embodiment of the transmitter of the present invention. The processor 3 is of the MOTOROLA 6802 type which includes 128 live memory octets or eight bit bytes 5. The programme carried out by the processor is recorded in the read-only memory 4 which is of the INTEL 2716 type, the capacity of which is 2048 octets. The decoder 6 which is of the 74LS 138 type, receives the most significant address weights from the processor and generates mutually exclusive selection signals to the circuits 4,7,8 and 9. The multiplexor 9 which is of the 4512 type, enables one of the input signals 21 to 27 selected by three of the bits of the address bus 31 to be multiplexed to the most significant bit of the data bus 30.The output register 7, which is of the 74 LS 259 type, is constituted by eight registers of one bit each which may be individually addressed; as the charged or signed bit is of a low address weight, it is loaded in the given address by three other bits of the address bus 31. The non-volatile memory 8, which is of the 5101 type, is of CMOS technology and its selection is influenced not only by the decoder 6 but also by the output regiater 40 via the integrator network 15. The memory 8 is controlled so as not to become volatile with respect to the storage of operating parameters of each application. In the rest position, the potential line 2 floats in such a way that only the non-volatile memory 8 and the junction gate 10, which is of the 4078 type, are supplied with voltage which is fed by the battery 12.In this case, the power consumption of the transmitter is negligible.

As soon as one of the input lines 21 to 27 passes into the active condition, the relay 11 actuated by the gate 10 is triggered (ie closed) and feeds all the components by bringing the potential 2 to the potential 1 of the battery. The processor 3 then carries out its initialization sequence under voltage, programmed in the read-only memory 4, and acts on the output register 7 via output line 41 which has the result of connecting the supply of all the components to the battery 12.

The processor 3 uses the output register 7 via output line 44 to open, dial the numbers and close the telephone line by means of the relay 14. The output register 7 via output line 43 enables the processor to transmit the modulation directly by frequency changes in accordance with specified standards, for example P.T.T. (French Post Office); the filter 19 is a low pass active filter whose role is to suppress the high frequency component contained in the rectangular signal present in the output line 43. The output reset line 42 enables the processor 3 to actuate a local alarm if a device of this type is connected to the output reset line 42.The speech signal carrying the information relating on the one hand to the different telephone tones, and, on the other hand,-the modulation generated by the MOD EM at the other end of the telephone line is amplified to saturation by the operational amplifier 18, which is of the 2 M 324 type, and is then applied to the breaker input 100 of the processor 3. This arrangement enables the programmed frequency to be measured with simple logical filtering. The input line 21, read via the multiplexor 9 informs the processor 3 when the line is active that the required cycle is a programming and not an alarm cycle.If, on the other hand, one of the lines 22 to 27 is active, the processor 3 carries out an alarm cycle and, in accordance with the active line 22 to 27, it emits a corresponding message (for example, FIRE on line 22, THEFT on line 23 etc.) The processor computes the time lapse by reference to the programme which it is carrying out and to the duration of the machine cycle given by its quartz clock 16.

At the end of the programming or alarm cycle, the processor 3 itself switches the voltage off from the system by opening the relay 11 by means of an action on the register 41. An adequate period before this action on the output line 41, the processor disconnects the non-volatile memory 8 by acting on the output line 40 so as to protect the non-volatile memory 8 against false entries which might be accidentally produced during release from voltage ie voltage transients.

The integrator network 15 ensures the disconnection of the memory 8 during the jumps which the line 40 may undergo during the application and the release from voltage (voltage transients).

It goes without saying that in accordance with the state of integration techniques, all or part of the components constituting the construction described above may be integrated in a monocircuitwithout constituting a basic modification ofthe present invention.

Preferably, the rate of transmission of the alarm message by the transmitter is either 110 bits per second or 300 bits per second.

Preferably, the telephone alarm transmitted includes means for detecting the frequency of the space state generated by a modulator as a sign off to a transmitted message. Preferably, this detection is ensured by a logic unit in a read-only memory.

The automatic telephone transmitter of the inven; tion may be used in all cases in which it is desired to call subscriber(s) during the occurrence of a state of emergency at the site at which the transmitter is located.

The transmitter is particularly useful in all applications in which the same type of telephone transmitter is desired to be adapted to the particular conditions of different sites to be monitored, or if it is desired to modify the operating parameters of a transmitter which has already been installed with a maximum ease of adaptation and a minimal adaptation cost (in practice the cost of a telephone call).

Claims (11)

1. Atelephone alarm transmitter for automatically dialling pre-stored telephone numbers following the occurance of a state of alarm, each telephone, the number of which is pre-stored, being connected to a teleprinter via a MODEM, comprising means for transmitting messages, coded to the modular standards of the telephone network to which the means are connected, such that a readily intelligible alarm message is automatically printed on the teleprinter connected to a telephone which responds to said dialling.

2. A transmitter as claimed in claim 1, wherein the required modulation function is programmed in a monolithic memory having at least one processor which the performs the encoding.

3. A transmitter as claimed in claim 1 or2, wherein the speed of transmission of the message by the transmitter may be either 110 bits/sec, or 300 bits/sec.

4. A transmitter as claimed in claim 1, comprising a means for detecting the frequency of the space state generated by a modular as a sign-off to a transmitted message.

5. Atransmitter as claimed in claim 4, wherein the detection of the space state frequency generated by a modulator is ensured by a logic unit in a read-only memory.

6. A transmitter as claimed in claim 1, comprising a monolithic memory of CMOS technology, controlled so as not to become volatile with respect to the storage of the operating parameters of each application.

7. A transmitter as claimed in claim 6, comprising a means for programming the non-volatile memory by telephone by demodulating the signal emitted by a MODEM at the other end of the telephone line.

8. A transmitter as claimed in claim 7, wherein a demodulation function is stored in the read-only memory and the demodulation is carried out by a processor.

9. A transmitter as claimed in claim 1,wherein the transmitter detects the different tones required for the dialling of telephone numbers and the setting up of a telephone call, by means of the read-only memory and a processor.

10. Atransmitter as claimed in claim 1, comprising means for altering the pre-stored telephone numbers by demodulating signals transmitted by a MODEM.

11. A telephone alarm transmitter substantially as herein before described with reference to and as illustrated in the accompanying figure of drawings.