JPH06152609A - Information transmission system - Google Patents

Abstract

PURPOSE:To prevent runaway of a transmission microcomputer by connecting lots of transmitters in parallel with a signal line to both ends for which a receiver and a termination resistor are connected and sending a signal inputted to the transmitter to the receiver through the signal line so as to reduce power consumption. CONSTITUTION:A reset pulse whose pulse width or level differs from that of each of count pulses more than the maximum value of an address of a transmitter is inserted to each count pulse as a composite pulse train in which the period of the count pulse is set longer than the program execution time of a transmission microcomputer superimposed on a power supply voltage fed from a receiver 1 to a transmitter 4. When the transmitter 4 detects the reset pulse, the transmitter microcomputer is reset and the transmitter address is set, then the standby mode is set, the transmitter 4 whose address reaches '0' by decrementing '1' from the address set by a succeeding count pulse transmits input information to the signal line, the transmitter is set to the standby mode, thus the transmitter 4 whose address is smaller sends sequentially input information to the signal line. Thus, the power consumption is reduced and the runaway of the transmitter microcomputer is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact connected to a plurality of transmitters in parallel with two signal lines, one end of which is connected to a receiver and the other end of which is terminated by a terminating resistor, and which is input to the transmitter. This is an information transmission system in which signals (on / off), analog signals, and digital signals are transmitted to a receiver through signal lines.

[0002]

2. Description of the Related Art Conventionally, a transmitter has a receiving function, an address signal is sent from a receiver to a transmitter having a different address, and a transmitter having an address matching the sent address signal is input information. Is a so-called polling method in which the signal is sent to the signal line.

[0003]

In the polling method, it is necessary for each transmitter to have a reception function and the receiver to have a transmission function, which complicates the structure and constantly monitors for address coincidence. Therefore, the current consumption has also increased. In addition, the address of each transmitter is sent from the receiver to the signal line in sequence, and the transmitter receives this and after confirming that it matches its own address, it sends its own input information on the signal line. There was a drawback that the usage efficiency was poor.

[0004]

In order to solve the above problems, according to the present invention, two signal lines are extended from a receiver terminal, and a terminating resistor is connected to the end of the signal line. Between the transmitters, a number of transmitters with different addresses other than 0 are connected in parallel so that the input information to the transmitter can be transmitted to the receiver. Replace the count pulse with a count pulse and a reset pulse with a different pulse width or amplitude for each fixed number of count pulses greater than the maximum value of the machine address, and set the cycle of the count pulse to the maximum value of the program execution time of the transmitting microcomputer. Superimpose a long, complex pulse train,
After detecting the reset pulse by the transmitter and resetting the transmitting microcomputer, set the transmitter address value to the standby mode, subtract 1 from the transmitter address value set for each subsequent count pulse, Transmitters with a value other than 0 are in standby mode, transmitters with 0 are in standby mode after sending input information to the signal line, and this is repeated to repeatedly input the input information of all transmitters in sequence. It was transmitted to. In addition, the power supply of the transmission microcomputer is supplied from the signal line with the electric power stored in the large-capacity capacitor via the constant current circuit or the resistor, and the transmission microcomputer is forcibly reset at a fixed cycle by the glue set signal from the signal line, and the program is executed. The standby mode was set to prevent runaway of the transmitting microcomputer and average the supply current over time to reduce it.

[0005]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is a block diagram showing the basic configuration of the present invention. 1 is a receiver, 2 and 3 are signal lines, 4 and 4'are transmitters, and 5 is a terminating resistor. The transmitters 4, 4 ', etc. all have different addresses except 0 and have a single or a plurality of information input terminals. FIG. 2 is a block diagram of an embodiment of the transmitter of the present invention. Reference numerals 6 and 7 denote connection terminals for signal lines, 8 and 9 are transmission transistors, 10 is a power supply series resistor, 11 is a power supply large-capacity capacitor, and a positive power supply for the transmission microcomputer 14 via a three-terminal regulator 12. It becomes 13. When transmitting information, the transmission transistors 8 and 9 have the output 22 of the transmission microcomputer set to HIGH, so that the transistors 17 and 1
7'is turned on and class A operation is performed. At other times, resistance 1
A charging circuit for the large-capacity capacitor 11 in series with 0 is configured. As will be described later, a composite pulse having a number of count pulses between reset pulses having different amplitudes or pulse widths is superimposed on the signal line. From the signal line terminal 6, the reset pulse and the count pulse are separated and shaped by the reset and pulse separation shaping 15 in the superimposed pulse,
A reset signal is output to the reset terminal 18 of the transmission microcomputer, and a count pulse is output to the count terminal 16.
An address switch 21 is connected to the address terminal 19 of the transmitting microcomputer which is LOW when opened, and the common contact side thereof is connected to the output terminal 20 of the transmitting microcomputer. After resetting, the transmission microcomputer sets the output terminal 20 to HIGH and reads its own address from the input terminal 19. With such a configuration, it is possible to reduce power consumption in a steady state.
The transmitting microcomputer sequentially subtracts the read self address by one by the count pulse following the reset pulse. When the result is other than 0, the transmitting microcomputer has a high impedance with respect to the signal line in the standby mode until the next count pulse arrives, and the transmitting microcomputer having the subtraction result of 0 outputs the input information to the signal line. In the output mode, the transmitting microcomputer first reads the input value of the information input terminal 23. Next, the switching output terminal 22 is set to HIGH,
The switching output transistors 8 and 9 are operated in class A. The read input value is A / D converted and becomes a combination of tone signals by the outputs 24 and 25 and the low-pass filters 26 and 26 ′, and drives the output transistor through the level shift diode 27 and the capacitor 28 to send information to the signal line. Is sent. FIG. 3 is a block diagram of an embodiment of the receiver of the present invention. Reference numerals 29 and 30 are connection terminals of signal lines, and the input tone signal passes from the input isolation transformer 31 to the input amplifier 32 and the information input terminal 34 of the signal processing microcomputer 33.
To enter. The processing program of the signal processing microcomputer 33 sets thresholds above and below the input value, processes all values outside the upper and lower thresholds as contact signals, and determines values between the upper and lower thresholds as analog values. As a result, the transmitter can support both contact input and analog input with the same configuration. The signal processing microcomputer uses the pulse output terminal 36 to connect the signal line drive transistors 37, 38,
The signal line is driven by 39. The resistors 40, 41, 42 serve as load resistors for the signal lines. The power supply to the transmitter is from the battery 45 to the transistor 38, resistors 40, 4
1 and 42. Therefore, if the voltage at the connection point between the resistors 41 and 42 is monitored by the comparator 35, the disconnection of the signal line can be detected. An analog value of the input information is corrected and converted according to the sensor characteristic, and is output to the external interface terminal 44 via the external interface driver 43. It is possible to connect a personal computer to the external interface and perform processing according to the application. FIG. 4 is a waveform and timing chart showing an example of the voltage waveform of the signal line of the present invention, and 46 is a voltage waveform sent from the receiver, which rises when the switch is turned on, and when this becomes a certain voltage or more, a reset pulse 47, 47 'count pulse 4
8, 48 'are superimposed on the power supply voltage and output. The reset pulse changes the count pulse and pulse width as shown in the figure, or
Or change the amplitude so that it can be divided. The interval between each pulse is set to be larger than the maximum value of the transmitter program execution time between them. The number of count pulses between reset pulses should be greater than the maximum value of the connected transmitter address. 49, 5
Reference numerals 1, 53, 55 denote the timings of sending tone signals 50, 50 ', 52, 52', 54, 54'55 from the respective transmitters in the order of addresses. Each signal is transmitted without duplication.

[0006]

As described above, according to the present invention, the information transmission and the power supply of the transmitter can be performed by only two signal lines, the transmitter can support both the analog voltage input and the contact input, and the current consumption can be reduced. It is possible to prevent the runaway of the microcomputer of the transmitter while minimizing the number of times. Further, the time required for information transmission from one transmitter can be shortened as compared with the normal polling method.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention.

FIG. 2 is a configuration diagram of an embodiment of a transmitter of the present invention.

FIG. 3 is a block diagram of an embodiment of a receiver of the present invention.

FIG. 4 is a waveform showing an example of a voltage waveform of a signal line of the present invention,
Timing diagram

[Explanation of symbols]

1 Receiver 2, 3 Signal Line 4, 4'Transmitter 5 Termination Resistor 6, 7 Connection Terminal with Signal Line 8, 9 Transmission Transistor 10 Power Supply Series Resistor 11 Power Supply Large Capacitor 12 Three-Terminal Regulator 13 Power Supply 14 Transmission microcomputer 15 Reset pulse separation and shaping circuit 16 Transmission microcomputer count terminal 17, 17 'Transmission switching transistor 18 Transmission microcomputer reset terminal 19 Transmission microcomputer address terminal 20 Transmission microcomputer output terminal 21 Address switch 22 Transmission Microcomputer switching output terminal 23 Information input terminal 24, 25 Transmission microcomputer information output terminal 26, 26 'Tone signal generation low-pass filter 27 Drive signal level shift diode 28 Drive capacitor 29, 30 Receiver signal line connection terminal 31 Reception Input of machine Edge transformer 32 Input amplifier of receiver 33 Signal processing microcomputer of receiver 34 Information input terminal of signal processing microcomputer of receiver 35 Disconnection detection comparator 36 Pulse output terminal of signal processing microcomputer of receiver 37, 38, 39 Signal line driving transistor 40, 41, 42 Signal line load resistance of receiver 43 External interface driver 44 External interface terminal 45 Receiver power supply 46 Voltage waveform sent from receiver 47, 47 'Reset pulse 48, 48' Count pulse 49, 51, 53, 55 Transmission timing diagram of each transmitter 50, 50 ', 52, 52', 54, 54 ', 55 Tone signal

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04L 29/12 8220-5K H04L 13/00 317

Claims (5)

[Claims] 1. A receiver information input / transmitter power supply output line (hereinafter referred to as a signal line) is extended from a receiver terminal, and a terminating resistor is connected to the end of the line to connect the receiver terminal and the terminating resistor. In an information transmission system in which a number of transmitters having different addresses except 0 are connected in parallel and the input information to the transmitter is transmitted to the receiver, the transmitter is connected to the power supply voltage supplied from the receiver to the transmitter. A composite pulse train in which a count pulse and a reset pulse with a different pulse width or amplitude are inserted for each fixed number of count pulses greater than the maximum value of the address, and the cycle of the count pulse is longer than the maximum program execution time of the transmitting microcomputer. Is set, the transmitter detects this set pulse, sets the transmitter microcomputer, sets the transmitter address value, sets the standby mode, and sets each subsequent count pulse. 1 is subtracted from the transmitter address value, the transmitters whose value is other than 0 are set to the standby mode, and the transmitters of 0 are set to the standby mode after sending the input information to the signal line. An information transmission system configured to repeatedly transmit the input information of the transmitter to the receiver in sequence. 2. The power source of the transmission microcomputer is supplied from the signal line with electric power stored in a large-capacity capacitor via a constant current circuit or a resistor, and the transmission microcomputer is reset at regular intervals by a glue set signal from the signal line, An information transmission method in which the standby mode is set after program execution, and the supply current is averaged over time to reduce it. 3. A different address is given to each transmitter,
An information transmission method in which an address is set by a reset pulse from the signal line, the set value is counted down by a count pulse from the signal line, and input information is transmitted from the transmitter when this value reaches a certain value. 4. An information transmission system for monitoring an integrated value of a voltage of a signal line by a transmission microcomputer, and resetting the transmission microcomputer when this value is a certain value or more and a reset pulse superimposed on the signal line is received. 5. An information input is provided with upper and lower thresholds, inputs outside the upper and lower thresholds are determined as contact inputs, and inputs between the upper and lower thresholds are determined as analog inputs.
An information transmitter that can support contact input and analog input with the same configuration.