JPS6238900B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication system that makes it possible to effectively use transmitted information without setting the content of transmitted information in a fixed pattern or increasing the number of information lines.

As shown in Figure 1, a parent unit P has n slave units C ₁ to
When C _o is connected and base unit P collects information from the slave unit, the communication method is base unit P - slave unit C.
A half-duplex asynchronous communication system is often used in which information is not exchanged at the same time. in this case,
It is necessary to distinguish whether the information is from the parent device P to the handset C or the information from the handset C to the parent device P.

Conventionally, in the case of this half-duplex asynchronous communication method, the master unit and slave unit communicated with each other in 8-bit units (bytes).
When sending and receiving bytes, for example, the first byte of information from the parent device to the child device can be used to distinguish whether the information is from the parent device or the child device, as shown in Figure 2. The logic of the 8th bit is fixed to "1", and the remaining 7 bits are used as slave unit address information. The 8th bit of the 2nd byte from the parent device to the child device is fixed to logic "0", and the 8th bit of both bytes of information from the child device to the parent device is fixed to logic "0".

In this way, if the 8th bit of the communication information is a logic "1", it is the first byte of information from the base unit, and the next 8th bit of logic "0" is information from the base unit. In addition, information in which the 8th bit is logic "0" can be distinguished as information being sent from the child device to the parent device.

However, the logic of the 8th bit of communication information is set to “1”.
Since it is always fixed to "0" from 0 to 1, only 7 bits of communication information can be used effectively. (Figure 2 shows the bit structure of conventional communication information.) In addition to the information line, as a means of effectively using all 8 bits of communication information, an information line is used to distinguish whether the transmission is from the base unit or not. A method of providing a separate line has also been used, but this method has the problem of requiring an extra line between the parent unit and the slave unit.

In order to solve the above-mentioned drawbacks of the conventional example, the present invention does not differentiate based on the information from the base unit, but detects the first sentence of the information from the base unit by time monitoring in each slave unit, and then transmits the information. The present invention provides a communication method that distinguishes whether the information being received is from the master device or the information from the slave device, and makes effective use of all bits of information.

Embodiments will be described in detail below with reference to the drawings.

FIG. 4 shows an embodiment of the slave unit of the present invention, where 1 is a fundamental frequency oscillation circuit, 2 is a communication interface, and 3 is a serial signal to be transmitted to a parallel signal, and a parallel signal to be transmitted. a serial/parallel signal converter (hereinafter abbreviated as signal converter) that converts the information into a serial signal; 4 is a timer with a re-trigger configuration that operates for more than 1 byte transmission time when 1 byte of transmitted information is received; 5 is a child Device address match detection unit, 6 is a data register for storing 2 bytes, 7 is a 1st byte detection unit, 8 is a device address match detecting unit, and when the child device address matches, it receives data from the second byte onwards, and when data reception is completed, the parent This is an internal control circuit that immediately starts transmitting data to the machine.
0 is a data register for transmission. Moreover, FIG. 5 is a signal waveform diagram of each part.

Fig. 6 shows the reception completion signal d and the timer signal e, 1.
The relationship between the byte-th detection signal h is shown. The operating time Ti of timer 4 is set so that Ti>1 byte transmission time. Further, this timer has a re-trigger configuration in which it is triggered at the falling edge of the signal of timer 4. For example, the next reception completion signal d within the set time of Ti
When (d-2 in FIG. 6B) is input, the Ti timer starts operating again from here. In this case, the timer signal e extends to Ti'. Timer signal e is normally at "H" level. It maintains the "H" level until it receives one byte of transmitted information and the timer 4 is triggered.

Assume that the timer signal e is now at the "H" level in each slave device. Here, in order to collect data from the slave unit, the operation of each slave unit when transmitting the first byte of information with the bit configuration as shown in Figure 3 is shown in the signal waveform shown in Figure 5. explain. a is a signal waveform between the parent device and the slave device. When each handset receives this serial information b-1, the signal converter 3
Received parallel data f-1 and reception completion signal d-1
Output. The time Td of this reception completion signal d is set to Td<1 byte transmission time. When the reception completion signal d-1 falls, the timer 4 is triggered and the timer signal e goes “L”.
become the level. If the received parallel data f
-1 and the address of the slave unit, that is, the address matching detection unit 5 of the slave unit to which the base unit is about to send information outputs a match signal g. The first byte detection unit 7 outputs the first byte detection signal h only when the timer signal e is "H" and the coincidence signal g is "H", and upon receiving this signal, the internal control circuit 8 starts operating. . In other handsets for which the match signal g does not become "H", the timer 4 only becomes "L" due to the first byte signal (or reception completion signal) from the parent device, and the internal control circuit 8 does not start operating. .

Next, when the second byte (b-2) is successively received from the base unit, the signal converter 3 of each slave unit receives the reception completion signal d-2 and the received parallel signal f in the same way as the first byte from the base unit. -2 is output. Reception completion signal d-
At the falling edge of 2, timer 4 is retriggered and restarts.
Keep “L” during Ti. Even if the received data of the second byte coincides with the handset address (g') by chance, the first byte detection signal h cannot be obtained because the timer signal e is "L". In this way, the timer signal e
If all the information received while is "H" is treated as the first byte information from the base unit, then a fixed bit can be provided like the conventional bit configuration shown in Figure 2 to determine if the information is from the base unit. There is no longer a need to distinguish whether the information is from a slave device or not.

When the handset addresses match and the handset has completed receiving 2 bytes, it sends the handset information to the base. When the 1-byte detection signal h is input, the internal control circuit 8 starts operating, outputs the transmission data register control signal k, and prepares for transmission. When the second byte b-2 is received, a latch signal i is output to save the received parallel data f-2, and the data register 6
When the second byte of received data is stored, the internal control circuit 8 starts transmitting data to the slave device. First, the first byte transmission signal j-1 of the slave unit is outputted, and the signal converter 3 is caused to start transmission. The signal converter 3 converts the transmission parallel data m-1 into a serial signal and starts transmission. (c-1) When the internal control circuit 8 outputs the transmission signal j-1, it outputs the transmission data register control signal l and prepares to transmit the second byte.
Since the transmission time of 1 byte is constant, 2
After outputting the byte-th transmission signal j-2, the signal converter 3 converts the transmission parallel data m-2 into a serial signal and transmits it. (c-2) Also, if the handset address does not match,
The information sent by the handset with the matching handset address will also be received, but in this case, as shown in Figure 6C, from the falling edge of the reception completion signal d-2 to the falling edge of the received signal d-3. If the set time T _i of timer 4 is made longer than the time until the descent, the timer signal e
stays “L” even while the handset is transmitting information, so a handset with an unmatched address will not receive information sent by a handset with a matching address as information from the base unit. .

That is, T _i is the transmission time of T _i >1 byte + the processing time from when the slave unit completes receiving the second byte from the base unit until transmitting the slave unit information. If T _i is set in this way, information can be transmitted without any problem, but new information cannot be collected until the timer signal e becomes "H" again.

Although 2-byte transmission/reception transmission has been described, it does not matter how many bytes the transmitted information is. Also, the main unit
Not only information transmission between handsets, but also information transmission between handsets is possible.

As described above, according to the present invention, by providing a timer that detects the first byte of information transmitted by each slave unit, it is possible to determine whether the first byte of information from the base unit or the first byte from the slave unit is detected. There is no need to provide fixed bits or information lines to distinguish between eyes.

Since fixed bits are not required for information data, all bits of the information content can be effectively used as information.

Since no information line is required, there are fewer connection lines between the parent unit and slave units.

While the timer is running, new information collection is prohibited, but once the timer returns, communication is possible not only between the base unit and the slave unit, but also between the slave units.

There is no waiting time when the child device transmits data to the parent device, so the communication speed is fast.

Low power consumption is achieved because only the handsets with matching addresses operate.

It is possible to obtain many effects such as:

[Brief explanation of the drawing]

Figure 1 is an overall configuration diagram of the system, Figure 2 is:
3 is a diagram showing the bit configuration of communication information according to the present invention, FIG. 4 is a diagram showing the configuration of a slave unit according to the present invention, and FIG. FIG. 4 is a signal waveform diagram at each part of the handset, and FIG. 6 is a signal waveform diagram. 1...Oscillation circuit, 2...Communication interface, 3...Serial/parallel signal converter, 4...
...Timer, 5...Slave unit address matching detection unit, 6
...Data register, 7...1st byte detection section,
8... Internal control circuit, 9, 10... Data register for transmission.

Claims (1)

[Claims] 1 n number of slave units are connected to the base unit, data collection and
In data transmission for communication, there is a serial/parallel signal converter that converts the transmitted serial signal into a parallel signal and the transmitted parallel signal into a serial signal, and when one byte of transmitted information is received, one byte transmission time + A timer with a re-trigger configuration that operates for more than the time from when the slave unit completes data reception from the base unit until it transmits the slave unit information, and a timer with a re-trigger configuration that operates for more than the time after the slave unit completes data reception from the base unit until it transmits the slave unit information, and a timer that uses the received data when the timer is not operating
A first byte detection section treats the first byte as the byte, a handset address match detection section uses the first byte as address information to detect a match between the handset addresses, and when the handset addresses match, it receives the data from the second byte onwards, and the data A communication method characterized in that each slave unit is equipped with an internal control circuit that starts data transmission to the base unit when reception is complete.