JPS6146600A - Transmitter for disaster preventor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a transmission device for disaster prevention equipment such as a fire alarm device, smoke prevention control device, fire extinguishing control device, etc., and particularly relates to a time division multiplex transmission device using pulse signals. .

``Prior Art'' Conventionally, there is a transmission device that controls a repeater or terminal device or transmits information in synchronization with a clock pulse of the device device, which is composed of a central processing unit and a plurality of repeaters or terminal devices. (For example, Japanese Patent Publication No. 53-42582, Japanese Patent Publication No. 53-465
Publication No. 43) "Problems to be Solved by the Invention" In such conventional transmission devices, pulse signals are affected by the distributed constant circuit of the transmission path, and especially when the transmission path is long, the pulse signal becomes slower, and the rise and fall times become longer. Therefore, the pulse signal received and waveform-shaped is delayed by a magnitude related to the distance and electrical characteristics of the transmission path. If this delay time is short compared to the period of the clock pulse, the signal can be received without any problem, but if it is longer than this, the signal corresponding to the position of the clock pulse cannot be received. Therefore, the transmission distance is limited by the electrical characteristics of the transmission path and the clock cycle (transmission speed). If you want to extend the transmission distance using a transmission line of the same quality, you must increase the clock cycle. That is, it is necessary to reduce the transmission speed. In this case, if the number of connected repeaters and terminal devices increases, it may take too much time to transmit information and control, which poses a problem.

[-Means for Solving the Problem] The transmission device of the present invention slows down the clock cycle when transmitting signals from the repeater or terminal device compared to the clock cycle when transmitting signals from the central processing unit. The present invention is characterized in that it is provided with a clock pulse generating means that can perform the following steps.

``Effect'' Transmission distance can be extended without significantly reducing transmission speed.

Embodiment An embodiment of the transmission device of the present invention will be described based on the block diagram shown in FIG. 1 and the timing chart shown in FIG. 2.

In Figure 2, the disaster prevention device includes a central processing unit RC, transmission lines LC, LT, LR, and multiple repeaters or terminals R.
, S. and central processing units R, C
The transmission section includes an oscillator 1 that generates a reference clock pulse.
, a counter circuit 2 for frequency division by n, a flip-flop circuit 3 for frequency division by 2, an AND circuit 4 powered by two people, an AND circuit 5 powered by three people, an OR circuit 6 powered by two people, and a negative circuit 7
1, a shift register 9 for serial to parallel conversion, an output circuit 10, 1.1, and an input circuit 12.

A rectangular pulse A is outputted and inputted to an AND circuit 4, a Flinopflonop circuit 3, and a counter circuit 2, respectively. The output of the flip-flop circuit 3 becomes a rectangular pulse B obtained by dividing the frequency of the reference pulse by two. The output of the counter circuit 2 becomes a rectangular pulse C whose frequency is divided by n. When the output of the counter circuit 2 is high, the central processing unit RC is in the transmitting state;
When low, it is in the receiving state. The AND circuit 4 generates the same pulse as the rectangular pulse A only during transmission, and goes low during reception.

The output of the counter circuit 2 is inverted by the NOT circuit 7 and input to the AND circuit 5. The AND circuit 5 outputs a receiving pulse E with the pulse interval doubled during reception. This is used as a clock pulse for the -1>yv' register 9. OR circuit outputs pulse F, which is a combination of six pulses D and pulse E. This pulse F converts parallel signals of address and command from a central processing unit (not shown) into a serial signal via an output circuit 1o, and outputs the serial signal in synchronization with a clock pulse D for transmission. This signal pulse G is passed through the output circuit 11 to the transmission line LT.
sent to.

The repeater or terminal RS receives the clock pulse F and the signal pulse 7G sent from the central processing unit RC at a transmission section (not shown). If it matches its own address, it analyzes the command, performs control corresponding to the command, and sends back the information it currently has. This return signal pulse H is delayed compared to the clock pulse F due to the dullness of the pulse in the transmission path. This signal pulse I] becomes dull while passing through the transmission line LR, and becomes a dull signal pulse H' before the input circuit 12. Input circuit 1
When the waveform is shaped by 2, the signal pulse 1-1 is further delayed.
become. This signal pulse H" is input to the shift register 9, and is synchronized with the receiving clock pulse E to convert the serial signal into a parallel signal. Data of the converted parallel signal is collected and analyzed by the central processing section. The signal pulse H" is delayed compared to the clock pulse E, but if it is smaller than the clock period, it can be received without any problem. Since the clock cycle is longer at the time of reception, the delay range of the signal pulse I'' can also be increased.In other words, the transmission distance can be extended.In this way, from the perspective of the central processing unit RC, only at the time of reception The transmission distance can be significantly extended simply by reducing the transmission speed.

The number of bits of the signal pulse G sent from the central processing unit RC and the clock cycle at this time, and the number of bits of the signal pulse H sent from the repeater or terminal R8 and the clock cycle at this time are as follows. The present invention is not limited to those shown in the embodiments, but can be easily implemented in various cases by using software such as a microcomputer. Although transmission lines LC, LT, and LR are still provided for each signal, it is possible to transmit each signal on the same line by combining and combining each signal, and by using the difference in signal form between voltage signals and current signals. It can also be carried out on the .

The same or more. This invention is a repeater or a terminal R8
This is especially effective when the number of bits transmitted from the transmission is small, since there is little reduction in transmission speed and the transmission distance can be extended.

"Effects of the Invention" As explained above, this invention maintains transmission quality and
Since it is possible to provide a transmission device suitable for a disaster prevention device that can lengthen the transmission distance without reducing the transmission speed much, it is extremely useful for disaster prevention.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a transmission device for a disaster prevention device according to the present invention, and FIG. 2 is a timing chart. RC/Central processing unit, R8... Repeater or terminal, LC, LT, LR transmission line, 1... Oscillator, 2...
...Counter circuit, 3...Flip-flop circuit, 4
, 5...AND circuit, 6. OR circuit, 7 NOT circuit, 8
゜9...77 register, 10.11...-output circuit,
12...Input circuit.

Claims (2)

[Claims] (1) Used in fire alarm systems, smoke prevention control systems, fire extinguishing control systems, etc., which are composed of a central processing unit and a plurality of repeaters or terminals, and the In a transmission device of a disaster prevention device that controls a repeater or terminal device or transmits information, if the clock cycle when the signal is sent out from the repeater or terminal device is different from the clock cycle when the signal is sent out from the central processing unit. A transmission device for a disaster prevention device, characterized in that it is provided with a clock pulse generating means. (2) The clock pulse generating means has a longer clock cycle when the signal is sent from the repeater or terminal device than the clock cycle when the signal is sent from the central processing unit. Transmission device for disaster prevention equipment.