JP2000231403A - Remote input and output system and slave device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote input and output system for changing the communicating speeds of all slave devices only by changing the communicating speed of a master device. SOLUTION: This remote input and output system is provided with one or more slave devices 31a for outputting inputted information or information obtained by working this inputted information and a master device 33 for fetching information outputted by the slave device 31a, and information is transferred by bi-directional communication for allowing the salve device 31a to respond to a prescribed signal from the master device 33. The slave device 31a is provided with a means 37b for detecting the communicating speed of the bi- directional communication based on the prescribed signal received from the master device 33 and a means 37b for operating the bi-directional communication with the master device 33 at the communicating speed detected by the detecting means 37b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to one or more slave units for outputting input information or information obtained by processing the information,
The present invention relates to a remote input / output system that includes a master unit that captures information output by a slave unit, and that transmits and receives information by bidirectional communication in which the slave unit responds to a predetermined signal from the master unit.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a configuration example of a conventional remote input / output system. The slave unit 31 of the remote input / output system converts, for example, an electric signal output by the sensor 10 which receives the projected light or the reflected light, converts the received light into an electric signal corresponding to the light amount, and outputs the electric signal, into a digital signal. An A / D converter 11, a CPU 13, a ROM 14, which are interconnected by the A / D converter 11 and a bus 17;
RAM 15, display unit 16, communication circuit 37, threshold changing circuit 18, and switch 19 connected to threshold changing circuit 18.
And The communication circuit 37 includes a switching circuit 37 for switching the communication speed of the bidirectional communication performed by the communication circuit 37.
a is connected.

The remote unit 31 of the remote input / output system
PLC (programmable
The master unit 33 includes a bus communication circuit 21 that receives an on-off signal from the slave unit 31 via a PLC input unit 36 described later, and a CPU 23 interconnected by the bus communication circuit 21 and the internal bus 27. , ROM
24, a RAM 25, a display unit 26, and an operation unit 30.

The remote input / output system is composed of
The on-off signal output by the communication circuit 37 of the
A PLC input unit 36 for receiving the bus communication circuit 21 of the base unit 33. The PLC input unit 36 is connected to the communication circuit 35 connected to the communication cable 38 and the bus communication circuit 21 of the master unit 33 by the bus communication cable 34a. And a bus communication circuit 34 connected thereto. The communication circuit 35 is connected to a switching circuit 35a for switching the communication speed of the bidirectional communication performed by the communication circuit 35. Parent machine 33
Is connected to each communication circuit 37 of the plurality of slave units 31 via the PLC input unit 36 and the communication cable 38, sequentially calls the slave units 31, and receives the data from the slave unit 31 having data to be transmitted. Two-way communication is performed by polling.

In the remote input / output system having such a configuration, the sensor 10 receives the projected light or the reflected light, converts the received light into an electric signal corresponding to the amount of light, and outputs the electric signal. A
The / D converter 11 converts the electric signal output from the sensor 10 into a digital signal and sends the digital signal to the CPU 13. CPU 13
Compares the transmitted electric signal with a predetermined threshold value stored in the RAM 15, and temporarily stores the comparison result in the RAM 15.

In this state, when there is a call from the master unit 33 in this state, the CPU 13 responds to indicate that there is data to be transmitted, and uses the temporarily stored comparison result as an on-off signal as the on-off signal. Send to 33. The communication circuit 37 performs transmission and reception accompanying these operations at the communication speed selected and set by the switching circuit 37a. Also, the CPU 13
Sensor 1 indicated by electric signal sent from A / D converter 11
The display unit 16 displays the light receiving level of 0 and the comparison result. The predetermined threshold value stored in the RAM 15 can be changed / updated by the threshold value changing circuit 18 by operating the switch 19.

The master unit 33 calls the slave units 31 sequentially,
If there is a response indicating that there is data to be transmitted, the comparison result is received from the child device 31, stored in the RAM 25, and displayed on the display unit 26 as necessary. The communication circuit 35 of the PLC input unit 36 performs transmission and reception associated with these operations at the communication speed selected and set by the switching circuit 35a. Further, base unit 33 performs an arithmetic process for controlling another connected device (not shown) set by operation unit 30 according to the received comparison result, and outputs a signal for a control operation.

[0008]

In the conventional remote input / output system as described above, the master unit 33 (PLC input unit 36) and a plurality of slave units 31 are connected by a single communication cable 38. However, when the communication cable 38 is long, the distortion of the signal waveform increases, and communication becomes impossible. Therefore, each of the switching circuit 35a and the switching circuit 3
7a, it is possible to switch the communication speed of the communication circuit 35 and the communication circuit 37, and the fastest possible with the determined length of the communication cable 38 at the stage of the installation planning of the remote input / output system. The communication speed is determined, and the parent device 33 and the child device 31 are installed with the communication circuit 35 and the communication circuit 37 set to the communication speed, respectively.

However, when the remote input / output system is actually installed at the site, the communication cable 38 is often longer than at the time of the installation plan due to the circumstances at the site, and is set at the time of installation due to the influence of noise and the like. It is often necessary to change the communication speed that has been set. However, handset 3
When there are many 1, it takes time to switch the switching circuit 35a of each slave unit 31 and go around the site. The present invention
It was made in view of the circumstances described above, and the first
An object of the present invention is to provide a remote input / output system that can change the communication speed of all the slaves by simply changing the communication speed of the master. In the second and third inventions, it is an object of the present invention to provide a remote input / output system slave unit that does not need to manually change the communication speed.

[0010]

A remote input / output system according to a first aspect of the present invention includes one or a plurality of slave units for outputting input information or information obtained by processing the information, and fetches information output by the slave units. A remote input / output system that transmits and receives the information by bidirectional communication in which the child device responds to a predetermined signal from the parent device.
Means for detecting the communication speed of the bidirectional communication based on the predetermined signal received from the master, and means for performing the bidirectional communication with the master based on the communication speed detected by the means. It is characterized by.

In this remote input / output system, one or a plurality of slave units output the input information or information obtained by processing the information, and the master unit fetches the information output by the slave unit, and receives a predetermined information from the master unit. The information is transmitted and received by the two-way communication in which the slave unit responds to the signal of the above. The slave unit detects the communication speed of the two-way communication based on a predetermined signal received from the master unit, and the means for performing the two-way communication communicates with the master unit based on the detected communication speed. Perform communication. Thus, by simply changing the communication speed of the master unit, the communication speeds of all the slave units can be changed.

A slave of the remote input / output system according to the second invention is a remote input / output system of the remote input / output system which transmits input information or information obtained by processing the information by two-way communication in response to a predetermined signal from the master. In the slave, based on the predetermined signal received from the master, a speed detecting means for detecting a communication speed of the bidirectional communication, and the communication speed detected by the speed detecting means, the master and the two-way communication, Communication means.

In the slave unit of this remote input / output system,
The input information or information obtained by processing the input information is transmitted by two-way communication in response to a predetermined signal from the master unit. The speed detecting means detects the communication speed of the bidirectional communication based on a predetermined signal received from the master unit, and the means for performing the bidirectional communication communicates with the master unit based on the communication speed detected by the speed detecting unit. I do. This eliminates the need to manually change the communication speed.

According to a third aspect of the present invention, in the slave unit of the remote input / output system, the speed detecting means includes a plurality of means respectively corresponding to a plurality of communication speeds that the two-way communication can take. A predetermined pattern of a start bit included in a predetermined signal is stored at a corresponding communication speed, and when the stored pattern substantially matches the predetermined pattern, a detection signal of the communication speed is output. It is characterized by having.

In the slave unit of the remote input / output system,
The speed detecting means, the plurality of means respectively correspond to a plurality of communication speeds that the two-way communication can take, and store a predetermined pattern of start bits included in a predetermined signal with the corresponding communication speed, and store. When the pattern substantially matches the predetermined pattern, a detection signal of the communication speed is output. Thereby, the speed detecting means can detect the communication speed of the two-way communication, and the means for performing the two-way communication can perform the two-way communication with the master unit based on the communication speed detected by the speed detecting means. Therefore, there is no need to manually change the communication speed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. FIG. 1 is a block diagram showing the configuration of an embodiment of a remote input / output system and a slave unit of the remote input / output system according to the present invention. The slave unit 31a of the remote input / output system receives, for example, the projected light or the reflected light, converts the received light into an electric signal corresponding to the amount of light, and outputs the electric signal (information) output by the sensor 10 as a digital signal. -To-A / D converter 1
1, a CPU 13, a ROM 14, a RAM 15, a display unit 16, which are interconnected by an A / D converter 11 and a bus 17.
It includes a communication circuit 37b, a threshold changing circuit 18, and a switch 19 connected to the threshold changing circuit 18.

The remote unit 31 of the remote input / output system
A master unit 33 including a PLC (programmable controller) installed at a position distant from the main unit a receives an on-off signal (data) from the slave unit 31a via a PLC input unit 36 described later. 21 and a CP interconnected by a bus communication circuit 21 and an internal bus 27.
A U23, a ROM 24, a RAM 25, a display unit 26, and an operation unit 30 are provided.

This remote input / output system includes a slave 31
a PLC input unit 36 for receiving the on-off signal output from the communication circuit 37b of the communication device 37a by the bus communication circuit 21 of the master unit 33. The PLC input unit 36 is connected to the communication circuit 38 connected to the communication cable 38. 35 and parent device 33
And a bus communication circuit 34 connected to the bus communication circuit 21 by a bus communication cable 34a. Communication circuit 3
5, a switching circuit 35a for switching the communication speed of the bidirectional communication performed by the communication circuit 35 is connected. Base unit 3
3 is connected to each communication circuit 37b of the plurality of slaves 31 via the PLC input unit 36 and the communication cable 38, sequentially calls the slaves 31a, and transmits the data from the slave 31a having data to be transmitted. Two-way communication is performed by the received polling.

FIG. 2 is a block diagram showing an example of the internal configuration of the communication circuit 37b of the slave unit 31a. This communication circuit 37b
Is a receiving circuit 40 connected to the communication cable 38 for receiving a signal from the base unit 33, a transmitting circuit 41 connected to the communication cable 38 for transmitting to the base unit 33, and a signal received by the receiving circuit 40. And a data receiving circuit 47 which receives a signal received by the receiving circuit 40 as data at the communication speed detected by the speed detecting circuit 42 and sends the signal to the bus 17.
(A means for performing two-way communication) and a data transmission circuit 48 which takes in the data sent via the bus 17 and sends it to the transmission circuit 41 according to the communication speed detected by the speed detection circuit 42.
(Means for performing bidirectional communication).

The speed detecting circuit 42 can be switched by the switching circuit 35a of the PLC input unit 36. The speed of the communication circuit 35 is, for example, 2 Mbps, 1 Mbps, 500 kb.
2Mbp out of 4 communication speeds of ps and 250kbps
detection circuit 43 (corresponding means) for detecting the communication speed of s
A detection circuit 44 (corresponding means) for detecting a communication speed of 1 Mbps, a detection circuit 45 (corresponding means) for detecting a communication speed of 500 kbps, and a detection circuit 46 (corresponding means) for detecting a communication speed of 250 kbps. ).

Each time the master unit 33 calls one of the slave units 31a, the detection circuit 43 to 46 detects the PLC input unit 36.
For example, a start bit pattern “101001” as shown in FIG.
As shown in (e), the data is stored at each communication speed. The detection circuits 43 to 46 determine whether or not the stored pattern matches the pattern sent via the reception circuit 40, and when they match, the detection circuits 43 to 4
The detection signal is sent to the data reception circuit 47 and the data transmission circuit 48 so that the data transmission circuit 6 operates at the communication speed to be detected. The data receiving circuit 47 and the data transmitting circuit 48 are operated by a clock having a frequency corresponding to a communication speed according to the sent detection signal.

The operation of the remote input / output system having such a configuration will be described below. The sensor 10 receives the projected light or the reflected light, converts the light into an electric signal corresponding to the light amount, and outputs the electric signal. The A / D converter 11 converts the electric signal output from the sensor 10 into a digital signal,
Send to The CPU 13 converts the transmitted electric signal into the RAM 1
5, and the comparison result is temporarily stored in the RAM 15.

In the speed detection circuit 42 (FIG. 2) of the communication circuit 37b, each of the detection circuits 43 to 46 causes the PLC input unit 36 to call each time the parent device 33 calls one of the child devices 31a.
For example, a start bit pattern “101001” as shown in FIG.
The data receiving circuit 47 and the data receiving circuit 47 determine whether the detected patterns 43 to 46 operate at the communication speed to be detected. The detection signal is sent to the transmission circuit 48. The data receiving circuit 47 and the data transmitting circuit 48 are operated by a clock having a frequency corresponding to a communication speed according to the sent detection signal.

In this state, when there is a call from the master unit 33 in this state, the CPU 13 responds indicating that there is data to be transmitted, and uses the temporarily stored comparison result as an on-off signal as the on-off signal. Send to 33. In the communication circuit 37b, as described above, the data reception circuit 47 and the data transmission circuit 48 perform transmission and reception in accordance with the communication speed detected by the speed detection circuit 42 (FIG. 2). Further, the CPU 13 causes the display unit 16 to display the light receiving level of the sensor 10 indicated by the electric signal sent from the A / D converter 11 and the comparison result. The predetermined threshold value stored in the RAM 15 can be changed / updated by the threshold value changing circuit 18 by operating the switch 19.

The master unit 33 calls the slave units 31a sequentially, and if there is a response indicating that there is data to be transmitted,
Receiving the comparison result from the slave unit 31a, the RAM 2
5 and display it on the display unit 26 as necessary. P
The communication circuit 35 of the LC input unit 36 includes a switching circuit 35
Transmission and reception associated with these operations are performed at the communication speed selected and set by a. Further, base unit 33 performs an arithmetic process for controlling another connected device (not shown) set by operation unit 30 according to the received comparison result, and outputs a signal for a control operation.

[0026]

According to the remote input / output system according to the first aspect of the present invention, the communication speed of all the slave units can be changed only by changing the communication speed of the master unit.

According to the slave unit of the remote input / output system according to the second and third aspects, it is not necessary to manually change the communication speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a remote input / output system and a slave unit of the remote input / output system according to the present invention.

FIG. 2 is a block diagram showing an example of an internal configuration of a communication circuit of a slave unit of the detection system according to the present invention.

FIG. 3 is a timing chart for explaining an operation of the communication circuit shown in FIG. 2;

FIG. 4 is a block diagram illustrating a configuration example of a conventional remote input / output system.

[Explanation of symbols]

 Reference Signs List 10 sensor 11 A / D converter 13, 23 CPU 15, 25 RAM 20, 34 bus communication circuit 34a bus communication cable 31a slave unit (slave unit of remote input / output system) 33 base unit 35, 37b communication circuit 36 PLC input unit 38 Communication cable 42 Speed detection circuit (speed detection means) 43 to 46 Detection circuit (corresponding means) 47 Data reception circuit (means for performing bidirectional communication) 48 Data transmission circuit (means for performing bidirectional communication)

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 5H220 BB11 CC09 CX05 CX09 EE09 EE10 FF09 FF10 JJ17 JJ35 JJ38 5K033 AA05 AA07 BA08 CA11 CB01 CB02 CB04 CC04 DA01 DB12 DB16 EA07 EC01 5K048 AA05 AA02 CA03 DA02 DB02

Claims (3)

[Claims] An information processing apparatus comprising: one or a plurality of slave units that output input information or information obtained by processing the information; and a master unit that captures information output by the slave units. In the remote input / output system that transmits and receives the information by the two-way communication to which the slave unit responds, the slave unit detects a communication speed of the two-way communication based on the predetermined signal received from the master unit. A remote input / output system comprising: means for performing the two-way communication with the master unit based on the communication speed detected by the means. 2. A remote unit of a remote input / output system that transmits input information or information obtained by processing the information by two-way communication in response to a predetermined signal from the parent device, wherein the predetermined information received from the parent device is And a means for performing the two-way communication with the master unit based on the communication speed detected by the speed detecting means. Remote I / O system slave unit. 3. The speed detecting means has a plurality of means respectively corresponding to a plurality of communication speeds that the two-way communication can take, and the means comprises a predetermined pattern of a start bit included in the predetermined signal. 3. The remote input / output system according to claim 2, wherein when the stored pattern substantially matches the predetermined pattern, a detection signal of the communication speed is output. Cordless handset.