JPH01293719A - Cpu starting control system used for simplex operation radio-communication system - Google Patents

Abstract

PURPOSE:To essentially and remarkably reduce a CPU abnormal operation by intermittently starting a CPU to cooperate with a simplex radio set by utilizing an existing squelch circuit. CONSTITUTION:When a carrier is received, the voltage of a node aNa goes to H. An output voltage V2 of an AVR130 is H. A gate signal to turn on a switch 123 is outputted from a squelch circuit 122 in a delayed state for approximately 1ms by the reception of the carrier. The gate signal of the circuit 122 is inverted at an inverter 126 and impressed to a comparator 203, a node dNd of an output part goes to H with a delay for its operating time, this signal is impressed to a reset terminal 202 of a CPU201, and the mode of the CPU201 is shifted from a sleeve mode to an operation mode. Since the input signal continues for one second, the CPU201 is operated during the time and after that shifted to the sleeve mode again, and the mode is maintained by an AVR204. On the other hand, when the PTT button of the radio set is pressed, the voltage of the AVR130 becomes L, an inverter output also becomes L while the button is pressed, and a comparator output H makes the CPU into the operation mode.

Description

[Detailed Description of the Invention] [Summary] A simplex radio communication system consisting of a simplex radio used for municipal disaster prevention radio, etc., and a control circuit having a CPU that cooperates with the radio to provide various services. With the aim of substantially reducing abnormal operation of the CPU caused by various factors, a simplex radio having a squelch circuit and a control circuit having a CPU that cooperates with the simplex radio have been developed. In the simplex wireless communication system, the CPU is configured to start up in response to a signal from a squelch circuit output in response to either carrier reception or transmission request operation.

[Industrial application field]

The present invention relates to a simplex radio communication system comprising a simplex radio and a control circuit (device) having a CPU for providing various services in cooperation with the radio.
A CP used in a simplex wireless communication system that substantially reduces abnormal CPU operation caused by various factors.
This relates to a startup control method for U.

The simplex wireless communication system of the present invention is used, for example, in various disaster prevention radio systems.

Note that with the simplex wireless communication system, although simultaneous two-way communication is not possible, it is possible to receive signals from the other station depending on the carrier, but press-to-talk (Press-to-talk) is possible at a timing different from (not overlapping with) this reception timing. -talk)
This refers to a system that also allows transmission based on transmission request operations such as.

[Conventional technology]

Conventionally, analog systems have been used for municipal disaster prevention radio communication systems, but there are limits to the frequency, and the operation rate (utilization rate) of disaster prevention radio is low (due to the availability of free time and existing equipment). Recently, digitalization has been promoted due to the need to utilize it to provide various resident services.

With digitalization, simplex radios are being equipped with control devices to perform various services, such as message transmission and automatic recording. For this reason, the control device has a built-in CPU such as a microprocessor. In addition, by installing a control device with a built-in CPU,
It becomes possible to improve the quality and content of disaster prevention information itself.

However, when such radio equipment and control devices are used for administrative disaster prevention, for example, they are often mounted on automobiles and used at disaster sites. In this case, the radio and control device are often supplied with power from an on-board dynamo, etc., and the power supply voltage often fluctuates significantly, and the CPU, which is sensitive to power supply voltage fluctuations, often experiences abnormal operations such as stopping or running out of control. easy. Alternatively, there may be many disturbances in the surrounding environment (i.e., movement makes the level of incoming radio waves unstable, which tends to cause abnormal CPU operation.The latter abnormal operation occurs when dry batteries are used as a power source). Furthermore, even if dry batteries are used, the CPU may malfunction due to a drop in power supply voltage due to the lifespan of the dry batteries.

Conventionally, in response to a change in power supply voltage, a CPU has taken measures to detect the voltage change, temporarily terminate the operation, and then automatically restart the CPU by issuing an interrupt.

In addition, a watchdog timer is installed to detect abnormal operation, and an interrupt is generated to automatically restart the system.

[Problem to be solved by the invention]

The automatic restart based on voltage detection due to power supply voltage fluctuations is effective in detecting power supply voltage fluctuations, but cannot cope with abnormal operations caused by other external factors. Therefore, there is a problem that a watchdog timer must be added.

Furthermore, automatic restart using the watchdog timer requires a dedicated circuit and requires complicated software processing in the CPU itself.

In view of the above, it is desired to solve the above-mentioned problems with a simple circuit configuration while taking advantage of the special characteristics of the simplex wireless communication system.

[Means to solve the problem]

In order to solve the above problems, the present invention focuses on the fact that radio equipment is always equipped with a squelch circuit to eliminate loud noises that occur when there is no human power, and utilizes this squelch circuit. , and focused on the low level of use of radio equipment for disaster prevention, etc., and developed a CPU with a simple circuit configuration.
This substantially reduces abnormal operation.

Figure 1 shows a CPU used in the simplex wireless communication system of the present invention.
A block diagram of the principle of the start-up control method is shown.

In the figure, a CPU 250 is configured to be activated by a squelch circuit 150. On the other hand, conventional automatic restart circuits based on voltage detection, watchdog timers, and their software processing are not provided.

[For production]

The squelch circuit 150 applies a squelch gate signal to the reset terminal of the CPU 250 upon carrier reception, and
When the CPU 250 is activated and a predetermined operation is performed, the CPU 250 enters the sleeve mode. The sleeve mode is a state in which power is supplied and the device can operate at any time, but does not perform any substantial processing.

On the other hand, during transmission, the squelch circuit 150 converts the squelch gate signal to C even in response to a transmission request such as press-to-talk.
Applied to the reset terminal of the PU 250, the CPU 250
to operate virtually from sleeve mode. CP[l
250 enters the sleeve mode after completing a predetermined operation.

Even when used for disaster prevention or when providing auxiliary services, the control device incorporating the wireless device and CPU only operates for a small amount of time compared to the total time. Therefore, even if a factor that causes abnormal operation occurs in this substantially dormant state, the CPU 250 will not be sensitive to it, and the possibility of abnormal operation occurring is significantly reduced.

In addition, even if a factor that causes abnormal operation occurs immediately after receiving the carrier, and once abnormal operation occurs,
Generally, such carrier reception is repeated for the same request, so recovery is substantially automatic. If such an abnormal operation occurs during a transmission request, the transmission request may be made again.

In this way, it is possible to substantially reduce abnormal operations of the CPU using existing equipment and functions.

〔Example〕

One embodiment of the present invention will be described with reference to FIG.

In the figure, a simplex radio device 100 includes an antenna 111,
High frequency amplifier 112. Primary mixer 113. Primary local oscillator 114. Primary intermediate frequency (IF) circuit 115. Secondary mixer 116. Secondary local oscillator 117. Secondary IF circuit 11
8, has a discriminator 119. in this way,
This example shows the case of double super. Simplex radio 1
00 further includes a bypass filter 120 and a detector 1211.
Squelch circuit 122, inverter 126, switch 12
It has 3. An amplifier 124 and a speaker 125 are connected after the switch 123. simplex radio 100
is provided with an AVR (automatic voltage control circuit) 130, which adjusts the input voltage to, for example, Vl = +13.8VDC (7) to a stable voltage of V2 = +8VDC (D).

The control device 200 that cooperates with the simplex radio device 100 is a C
A PU 201, an AVR 204, a PU 201, an AVR 204, and a PU 203 are provided as shown in the figure. CPU 201
A reset terminal 202 is provided to which the output of the comparator 203 is connected. Further, the comparator 203 has one input terminal applied with the output of the inverter 126 which is an inversion of the gate output of the squelch circuit 122, and the other input terminal applied with the reference voltage REF. CPU20
1 is based on the human power pressure VI = +13.8VDC, V, =
Power is supplied from the AVR204 which outputs +5V.

The squelch circuit 122 includes a switch 123 to prevent noise from being output from the speaker 125 when there is no received signal.
is turned off so that the output of the discriminator 119 is not applied to the speaker. On the other hand, when the signal I) is received, the squelch circuit 122 turns on the switch 123 so that the received signal is outputted through the speaker 125.

Referring to FIG. 3, the CPU startup operation upon carrier reception will be described.

When the carrier is received, the voltage Va at the node aNa becomes high level. The output voltage v2 of the AVR 130 is at a high level. Upon carrier reception, the gate signal from the squelch circuit 122 that turns on the switch 123 is approximately t I=
It is output with a delay of about 100 rns. The gate signal of squelch circuit 122 is inverted by inverter 126 and applied to comparator 203 . This signal is V. Indicated by After a delay of the operating time t of the comparator 203, the node dNd at the output section of the comparator 203 becomes high level, and this signal is applied to the reset terminal 20 of the CPU 201.
2 and the CPU 201 enters the "operating mode" from the "sleeve mode".

Since the received signal continues for Vj = 1 second, CPt120
1 operates during this period, and then shifts to "sleeve mode" again. The voltage from AVR204 is always V.

is supplied and maintains "sleeve mode".

Next, referring to Figure 4, C during press-to-talk.
The PU startup operation will be described.

When the press-to-talk (PTT) button of the simplex radio 100 is pressed, the voltage V2 of the AVR 130 goes to a low level. As a result, the voltage V at the output of the inverter 126 at the output stage of the squelch circuit 122. is low level while the press-to-talk button is pressed. As a result, the output voltage Vd of the comparator 203 becomes high level, causing the CPU 201 to shift from the "sleeve mode" to the "operation mode". During the above operation, the 8VR 204 continues to supply voltage V3 to the CPU 201 at all times.

The CPU 201 performs an open operation when the press-to-talk button is pressed, and then shifts to "sleeve mode" again. AVR 204 makes this "sleeve mode" possible.

Since it is a simplex wireless communication system, the carrier reception and the press-to-talk operation do not overlap in timing.

As is clear from the above, the CPU 201, which is configured to perform various services, actually operates only for a small amount of time compared to the entire time, so it may cause abnormal operation in the "sleeve mode". Even if a cause occurs that causes the program to run out of control, it will not run out of control because it is not operating in "sleeve mode."

Further, during the above operation, even if a cause for causing an abnormal operation occurs and an abnormal operation occurs, the carrier is received multiple times, so that the device is automatically restarted. In addition, the abnormal operation during press-to-talk may be caused by press-to-talk again.
All you have to do is talk.

To achieve the above, by utilizing the existing squelch circuit, there is no need for a voltage detection ring, reset circuit, watchdog timer, and its software processing, and the CPU
U 201 may be a conventional circuit that simply performs a reset operation.

〔Effect of the invention〕

As described above, according to the present invention, under the condition of simplex wireless communication system, by utilizing the existing squelch circuit, the CPU that cooperates with the simplex wireless device is activated intermittently, It was possible to substantially reduce the abnormal operation of the CPU.

[Brief explanation of the drawing]

1 is a principle block diagram of a CPU start-up control method used in the simplex wireless communication system of the present invention, FIG. 2 is a circuit diagram of a CPU start-up control system used in the simplex wireless communication system of an embodiment of the present invention, FIG. 4 is a start-up timing diagram of the CPU shown in FIG. 2. (Explanation of symbols) 1... Squelch means, 2... CPU. 100...Radio device, 111...Antenna, 112.
... High frequency amplifier, 113 ... Primary mixer, 114
...Primary local oscillator, 115...Primary IF circuit, 1
16... Secondary mixer, 117... Secondary local oscillator, 118... Secondary IF circuit, 119... Discriminator, 120... Bypass filter, 121... Detector, 122... ...Squelch circuit, 123...Switch, 124...Amplifier, 12
5...Speaker, 126...Inverter, 130...
... A VR, 200... Control unit, 201.
...CPU. 202...CPU reset terminal, 203...Comparator, 204...AVR0 heat t --H CPU start-up timing ε7 tag when receiving carrier in Figure 2, Figure 3
Figure 2 CPU startup timing diagram during press-to-talk Figure 4

Claims (1)

[Claims] 1. In a simplex radio communication system comprising a simplex radio device having a squelch circuit and a control circuit having a CPU that cooperates with the simplex radio device, either carrier reception or transmission request operation is performed. 1. A CPU activation control system for use in a simplex wireless communication system, characterized in that the CPU (250) is activated in response to a signal from a squelch circuit (150) that is output in response to a signal from a squelch circuit (150).