JPH0157399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote control system that connects a plurality of terminals in parallel to a series of transmission lines, sequentially calls desired terminals, and activates the terminal operations.
In particular, it relates to a remote control system for terminals equipped with means for confirming that desired terminals are being called in sequence. An ultrasonic alarm system is equipped with terminals for transmitting and receiving sound waves and controlled in a time-sharing manner, and multiple temperature detection and control terminals are connected in parallel along a series of transmission lines in multiple freezer compartments. It can be effectively used in a refrigeration management system that controls in a divided manner.

Conventionally, in this type of remote control system, as a method for confirming that a desired terminal has been called, the called terminal encodes its own machine number and sends it to the called party, such as a central control unit, through a transmission line. A so-called answer-back method is widely used, in which a message is sent to a server and a confirmation is received. This method is extremely reliable in confirming whether a desired terminal is correctly called, and is widely used in data communication systems using telephone lines. However, the circuit configuration and control method become complicated, and when applied to a system for remotely controlling a terminal device having only relatively simple functions, there is an inconvenience that the cost increases unnecessarily. Therefore, in such a remote control system for terminals with simple functions, it is common to use a dedicated transmission line for each terminal to ensure reliable control of each terminal. However, in this case, wiring of a large number of transmission lines is required, and therefore there is an inconvenience that an increase in wiring work costs cannot be avoided.

Therefore, the present invention eliminates the drawbacks associated with such conventional remote control systems, and makes it possible to accurately control a desired terminal when sequentially activating terminal operations of a plurality of terminals connected in parallel to a series of transmission lines. The present invention provides a remote control system for a terminal in an alarm system or the like, which is equipped with means for checking whether or not a call has been made.

According to the present invention, a plurality of terminals are connected in parallel to one series of transmission lines, and the terminals are operated by sequentially calling the plurality of terminals from a remotely located controller via the transmission line in chronological order. In the remote control system for terminals, each of the terminals has a certain electric circuit constant and is connected to the transmission line through a switch means, and each terminal is assigned a unique number. A preset counting circuit is provided, and a driving signal issued in response to a control signal from the controller drives the counting operation of the counting circuit of each terminal, and the counted value matches the unique number. When the transmission line and each of the terminals are closed via the switch means, and each time the drive signal of each of the counting circuits is sequentially sent to the transmission line, the signal of the transmission line is taken out. Sends an electrical level value corresponding to the electrical constant of each terminal device obtained by the section to the controller from the signal extraction section, and determines the terminal device connected to the transmission line based on the level of the electrical level value. The plurality of terminals are sequentially detected by the controller and confirmed that the detected electrical level value of the terminal is not different from a constant value determined from the electrical constant of each terminal. A remote control system for a terminal in an alarm system or the like is provided to confirm that the terminal is connected to the transmission line. below,
The present invention will be described in detail based on embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to an ultrasonic alarm system. In the ultrasonic alarm system shown in the figure, a central controller 50
is a series of transmission lines L ₁ consisting of two signal lines,
A plurality of ultrasonic reception terminals T ₁ , T ₂ , ...T _o ...T _N connected in parallel to L ₂ are individually called at regular intervals and called by sending a control signal. An ultrasonic pulse wave is emitted from the terminal T _o into the air in the warning area, and the reflected wave from within the area is received again by the terminal T _o , amplified by the operational amplifier 6, and transmitted to the central controller 50. . In the central controller 50, the reflected wave of the ultrasonic wave transmitted from the terminal T _o is transmitted through an intensifier 5, a rectifier 4, and an A/D converter 3, and is mainly configured with a microprocessor and memory means. The processed arithmetic processing unit 2 recognizes the reflected wave pattern as one reflected wave pattern along the time axis. This reflection pattern is stored in the memory means for each terminal T ₁ ...T _N , and a plurality of ultrasonic transmitting and receiving terminals T ₁ ...T _o ...T _N are time-divided by one central controller 50. It is controlled by That is, for example, if an intruder exists in the guarded area of the terminal T _o , the reflected wave pattern of the terminal T _o at that time will be different from the reference reflected wave pattern stored when the intruder was not present. is determined in the arithmetic processing unit 2, and as a result, an alarm signal is sent out to drive the buzzer 1 of the alarm device, causing the buzzer 1 to sound. However, due to electrical noise such as lightning getting into the transmission lines L ₁ , L ₂ , or for other reasons, the desired terminal T _o is not called correctly, and another terminal is connected to the transmission lines L ₁ , L 2 . ₂ or when two terminals are simultaneously connected to the transmission lines L ₁ and L ₂ and called, a difference from the standard reflected wave pattern will naturally occur, resulting in an error. This will alert you to the presence of an intruder. Therefore, the present invention aims to prevent such malfunctions, and the characteristic configuration of the present invention will be explained below.

Now, in the present invention, among the above-mentioned components, the A/D converter 3 is formed by a two-channel input A/D converter, and the reflected wave of the ultrasonic wave and the direct current flowing in the transmission line are It is configured to convert two types of analog data of current into digital data and supply the digital data to the arithmetic processing unit 2. Note that the selection of the channel of this A/D converter 3 is controlled by a control signal S of the arithmetic processing unit 2. In addition, rectifier 4 converts the reflected waves into AM
(Amplitude modulation) The filter 5 has the function of detecting waves, and the multiplier 5 has the function of selecting a frequency component of the ultrasonic reflected wave and amplifying the selected frequency component. In addition, the operational amplifier 6 extracts the AC current of the ultrasonic reflected wave flowing through the transmission line L ₁ and the DC current consumption of each terminal unit T ₁ ...T _o ...T _N as a voltage drop across the resistor R ₁ . amplify. Now, the transmission lines L ₁ and L ₂ are further provided with a control pulse generator 7 that sends out control pulses to the transmission lines L ₁ and L ₂ by being controlled by the control signal P from the arithmetic processing unit 2. This control pulse generator 7 has built-in switch contacts P ₁ , P ₂ , and P ₃ . The contacts P ₁ , P ₂ , and P ₃ are configured to be alternately connected to the transmission line L ₁ by switching,
Further, the contact P ₃ is always connected to the transmission line L ₂ . Contacts P ₁ , P ₂ and P ₃ of control pulse generator 7
Control pulse generation power supplies E ₁ and E ₂ are connected between the two. That is, the power source E ₁ is connected between the contacts P ₁ and P ₃ of the control pulse generator 7, and the power source E ₂ is connected between the contacts P ₂ and P ₃ of the control pulse generator 7. Note that the transmission lines L ₁ and L ₂ are wired within a restricted area, for example, inside a building that is subject to crime prevention. That is, as can be seen from the above, the control pulse generator 7 equipped with the central controller 50, the buzzer 1 of the alarm device, the operational amplifier 6, and the power supplies E ₁ and E ₂ is connected to the terminals T ₁ ...T _N. A controller is configured for the transmission lines _L1 and _L2 .

Next, the internal configuration of each of the ultrasonic transmitting/receiving terminals T ₁ ...T _o ...T _N and the connection relationship with the transmission lines L ₁ and L ₂ are shown in the block circuit diagram shown in Fig. 2. . As shown in the figure, each terminal has a pulse width identification circuit 8, a counter 9, a rotary switch 10, diodes D ₁ , D ₂ , capacitors C ₁ , C ₂ ,
It is configured to include an oscillator 11, an amplifier 12, an ultrasonic wave emitting/receiving element 13, a switch 14, and the like. The pulse width of the pulse signal applied from the transmission lines L ₁ and L ₂ is identified by the identification circuit 8, and when the pulse width is equal to or greater than a predetermined value, the pulse signal is applied to the address load terminal LD of the counter. This causes a number unique to the terminal to be set in the counter 9, as will be described later. The counter 9 is a preset type hexadecimal up counter that increases the count by 1 each time a pulse signal is applied to its count input terminal CL, and sends out an output signal from its output terminal CR when it reaches a set number. It is formed as. The counter 9 is supplied with power through the diode D ₁ , and the diode D ₁ also serves to prevent the charge accumulated in the capacitor C ₁ from flowing back into the transmission line L ₁ . Note that the capacitor C ₁ functions to prevent fluctuations in the power supply of the counter 9 due to the control signal being sent between the transmission lines L ₁ and L ₂ . The above-mentioned unique number setting for the counter 9 is performed by a rotary switch 10, which is of a type that sends out a 4-bit binary code signal. The unique number n of the terminal T _o is the switch 10
When you match the character face to n, the hexadecimal number corresponding to that n is set. When a pulse signal is input to the address load terminal LD of the counter 9, the hexadecimal unique number n set in the rotary switch 10 is set inside the counter 9 in response to the input of the pulse signal to the address load terminal LD of the counter 9. Then, when the same number of pulse signals is applied to the count input terminal CL for the hexadecimal number corresponding to the set unique number n and they match, a signal is sent from the output terminal CR and the switch 14 is closed. Therefore, the terminal T _o is electrically connected to the transmission lines L ₁ and L ₂ . In this case, one more count pulse is sent from the output terminal CR while the signal is being sent from the count input terminal.
When input to CL, the contents of counter 9 are cleared to 0000, and at the same time the output of output terminal CR becomes 0, switch 14 is opened again, and the terminal
T _o is released from the transmission lines L ₁ and L ₂ .

Now, diode D ₂ supplies power to the ultrasonic frequency oscillator 11 and capacitor C ₂
This functions to prevent the electric charge accumulated in the transmission line _L1 from flowing back into the transmission line L1.When the oscillator 11 is supplied with power, the oscillation command pulse OC coming from the transmission line _L1 generates a pulse of about 1 msec. An alternating current of ultrasonic frequency is generated for an instant to drive the transmitting/receiving element 13. Then, once every 0.5 to 1 second from the element 13,
An ultrasonic pulse wave of about 1 ms is emitted. In general, the power supplied to the oscillator 11 is a large amount of current, on the order of several amperes. When such a large current flows through the transmission lines L ₁ and L ₂ , undesirable phenomena such as voltage drop due to line resistance occur, so the current is averaged by the resistor R ₂ and the capacitor C ₂ . On the other hand, when switch 14 is closed as described above, power is applied to amplifier 12. When the ultrasonic pulse waves emitted from the emitting/receiving element 13 are reflected by walls or objects in the warning area, the reflected waves are received by the element 13 again.
The received ultrasonic reflected wave is current-amplified by an amplifier 12. The current-amplified reflected wave is sent as an alternating current to the transmission line _L1 through the signal line SL,
It is transmitted to the central controller 50 side.

Each terminal T ₁ ...T _o ... having the above-mentioned configuration
Figure 1 shows T _N connected in parallel to transmission lines L ₁ and L ₂ ,
The operation of the ultrasonic alarm system shown in FIG. 2 will be explained based on the time chart of signal waveforms shown in FIG.
In addition, the ultrasonic transmitter/receiver terminal set in advance here
The unique numbers of T ₁ , T ₂ , ...T _o ...T _N are 1, 2, ...N
There are no identical numbers, so the maximum unique number is N.

Now, the ultrasonic alarm system is activated by connecting the contact P ₁ of the control pulse generator 7 to the transmission line L ₁ . That is, when the contact P ₁ is connected to the transmission line L ₁ , the counters 9 in all the terminals T ₁ . . . T _{o .} . . T _N are powered on. In this state, when the control signal P of the arithmetic processing unit 2 of the central controller 50 is sent, the control pulse generator 7 sends the address load pulse 15 (FIG. 3A) between the contacts P ₁ and P ₃ to the transmission line. Send to L ₁ and L ₂ . As a result, all the terminals T ₁ , T ₂ , ...T _o , ...T _N have their respective counters 9
This means that a unique number has been set. Next, the control pulse generator 7 generates a count pulse 16, which is shorter than the address load pulse 15, between the contacts P ₁ and P ₃ .
occurs. As a result, the contents of all the counters 9 are incremented by 1, and the switch 14 is closed only in the terminal T1 with the unique number ₁ . Therefore the terminal
The internal circuit of T ₁ is connected to transmission lines L ₁ and L ₂ . In this case, the A/D converter 3 of the central controller 50
The voltage signal taken out by resistor _R1 is inputted to one channel terminal as CS (see Figure 3B). The level of this signal CS has a value proportional to the sum of the current consumption of all the counters 9 and oscillators 11 of each terminal _T1 ... _TN plus the current consumption of the amplifier 12 of the terminal _T1 . Needless to say. on the other hand,
At this time, if electrical noise mixes between the transmission lines L ₁ and L ₂ and two terminals, for example, terminals T ₁ and T ₂ , are accidentally connected at the same time, the third
As shown in Figure C, the level of the signal CS becomes an abnormally high level indicated by 22. Also, conversely, terminal T ₁ is also T ₂
If the terminal _T1 is not connected, the current consumption of the amplifier 12 of the terminal T1 is 0, so that an abnormally low level signal CS as shown at 22' in FIG. 3C appears. Therefore, if the level of the signal CS when each terminal device T ₁ ...T _o ...T _N is normally called is stored in the arithmetic processing unit 2 in advance, the terminal device can erroneously connect to the transmission line as described above. The central controller 50 can recognize that it is connected to L ₁ and L ₂ .

Now, when the terminal _T1 is called as described above, the contact _P1 of the control pulse generator 7 is connected to the contact P2 _.
, and an ultrasonic oscillation command pulse OC is sent to the transmission line _L1 . This ultrasonic oscillation command pulse
OC is shown as pulse signal 17 in FIG. 3A. When this pulse signal 17 is sent out, an ultrasonic wave is emitted from the emitting/receiving element 13 of the called terminal _T1 , and a reflected wave is received. As a result, the reflected wave is sent to the central controller 50 via the amplifier 12, resistor R ₁ and operational amplifier 6 of the terminal T ₁ , passes through the multiplier 5 and the rectifier 4 and then is sent to the A/D converter 3 . is applied as signal SS. In this case as well, if only the terminal _T1 is normally called, the signal SS has the pattern shown at 21, as shown in FIG. 3B. However, if the terminal T ₂ as well as the terminal T ₁ are accidentally connected to the transmission lines L ₁ and L ₂ , the signal SS becomes the pattern shown at 22 in FIG. 3C. In this way, the signal SS is pattern 2
2, the terminal is terminated by a normal call.
If only T ₁ is closed, it is determined that an abnormal pattern has been detected and that there is an intruder in the warning area, and an alarm signal is sent from the central controller 50 to the alarm device 1. , according to the invention:
As mentioned above, since it is confirmed by the CS signal of the A/D converter 3 whether or not there is an abnormality in the call, the arithmetic processing unit 2 can prevent the sending of the above-mentioned alarm signal.

On the other hand, due to electrical noise mixed into the transmission lines L ₁ and L ₂ , the count pulse input terminal CL of each counter 9
Assuming that one count pulse applied to the terminals disappears and the contents of the counters 9 of all the terminals T ₁ ...T _o ...T _N are 1 less than normal, the timing for each terminal to call is Although the signal CS is shifted by one count pulse, no level abnormality is observed in the signal CS applied to one input channel of the A/D converter 3. However, with N count pulses for each terminal T ₁ . . . T _N , it is impossible to close the terminal T _N . Even more (N+
1) Pulse generator 7 that controls the second count pulse
It is sufficient to always apply the voltage from . The pulse signal 18 in FIG. 3A shows this (N+1)th count pulse. Here, if up to N count pulses are used for all terminals T ₁ ...T _o
...If T _N is called sequentially and normal terminal operation is completed, no terminal close connection is performed even if (N+1) count pulses are applied, so A/D conversion The signal CS of device 3 is the third
The level shown at 24 in Figure D, i.e. the level 2 mentioned above.
2'. Therefore, the arithmetic processing unit 2 counts all the terminals T ₁ ...T _o by up to N count pulses.
...It can be recognized that T _N has finished calling in sequence. Conversely, if one of the up to N count pulses has disappeared, the final terminal T _N is connected by the (N+1)th count pulse. In that case, the signal of A/D converter 3
CS is equal to level 20 in FIG. 3B, as shown at level 25 in FIG. 3E. As a result, the arithmetic processing unit 2 can recognize that the terminal T _N has been closed and connected at the (N+1)th count pulse, and that normal sequential paging could not be achieved at the Nth count pulse. .

Furthermore, if the contents of the counters 9 of all the terminals T ₁ ...T _o ...T _N increase by 1 due to electrical noise mixed into the transmission lines L ₁ and L ₂ , they will be closed at the time of sending the Nth count pulse. On the contrary, the connection of the terminal device T _N to be connected will be canceled by opening the switch 14, and the signal at the A/D converter 3 will be disconnected.
The level of CS drops to level 22' in FIG. 3C. Therefore, the arithmetic processing unit 2 causes each counter 9 to increase its content during up to N count pulses,
It is possible to recognize that a successful call was not achieved.

From the above explanation, in the ultrasonic alarm system to which the present invention is applied, A/D conversion of the central controller 50 is performed by sending a series of (N+1) count pulses to the transmission lines L ₁ and L ₂ . The signal CS extracted from a part of the transmission line is detected by the device 3, and the signal
If the CS level is monitored by the processing unit 2,
Even if there is an abnormality in the ultrasound reflection pattern,
By recognizing in advance that there is an abnormality in the terminal's calls, it is possible to prevent erroneous alarm signals from being issued. In other words, it can be determined that a malfunction has occurred in the individual calling of the terminal, and based on the determination result, generation of a false alarm signal can be prevented.

The present invention has been described above with reference to an embodiment of an ultrasonic alarm system, but according to the present invention, a plurality of terminals are connected in parallel to a wide series of transmission lines, and each terminal is sequentially called. In a remote control system for operating terminals, it is possible to check whether or not a desired individual call has been achieved by simply providing a counter in each terminal, and there is no need to introduce special circuit means, resulting in low costs. Can be secured.
Moreover, since each terminal operation completes its correct operation in sequence, the reliability of the system is significantly improved. Furthermore, since it is possible to maintain a system in which one series of transmission lines is wired from one central controller and a plurality of terminals are connected in parallel to this, it is possible to maintain low costs in terms of wiring work.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the overall configuration of an ultrasonic alarm system when the present invention is applied to the system, Fig. 2 is a block diagram showing the configuration of a terminal, and Fig. 3 explains the operation of the present invention. FIG. 3 is a time chart of signal waveforms. 1...Alarm device, 2...Arithmetic processing unit, 3...A/D
Converter, 4... Rectifier, 5... Multiplier, 6... Operational amplifier, 7... Control pulse generator, 8... Pulse width discrimination circuit, 9... Counter, 10... Rotary switch,
11... Oscillator, 12... Amplifier, 13... Ultrasonic wave emitting/receiving element, 14... Switch, 50... Central controller.

Claims (1)

[Scope of Claims] 1. A plurality of terminals are connected in parallel to one series of transmission lines, and the plurality of terminals are sequentially called from a remotely located controller via the transmission line in chronological order. In a remote control system for operating terminals, each of the terminals is equipped with a certain electric circuit constant and is connected to the transmission line via a switch means 14, and each terminal is provided with its own unique information. A counting circuit for setting a number in advance is provided, and a driving signal issued in response to a control signal from the controller drives the counting operation of the counting circuit of each terminal, and the counted value corresponds to the unique number. When they match, the connection between the transmission line and each of the terminals is closed via the switch means, and each time the drive signal of each of the counting circuits is sequentially sent to the transmission line, An electrical level value corresponding to the electrical constant of each of the terminals obtained by the signal extracting unit _R1 is sent from the signal extracting unit to the controller, and connection is made to the transmission line based on the level of the electrical level value. The control device remotely detects a terminal device that has been detected by the controller, and confirms that the electrical level value of the detected terminal device is not different from a constant value determined from the electrical constant of each terminal device. A remote control system for terminals in an alarm system, etc., which confirms that the terminals are sequentially connected to the transmission line. 2. In the remote control system for a terminal in an alarm system, etc. as set forth in claim 1,
The unique number of the plurality of terminals connected in parallel to the transmission line is set by a plurality of integers corresponding to the number of the terminals, and the maximum number of the plurality of integers is set as the unique number. After the controller calls the terminal, further sends a drive signal to drive each of the counting circuits, and then reads the electrical level value obtained from a part of the transmission line by the signal extraction unit _R1 , Confirming that the plurality of terminals are sequentially connected to the transmission line by confirming from the read electric level value that none of the terminals is closed-connected to the transmission line. A remote control system for terminals in alarm systems, etc.