JPH09312658A - Data transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the data transmission device which can surely transmit data at a high communication rate and is rich in flexibility by making a 1st management device request the transmission device of information and a 2nd management device receive and input data outputted by the transmission device at the request. SOLUTION: Management devices 4 and 5 as operation display devices are connected to a bus L and, for example, the management device 4 requests an input device 1 as a transmission device having a specific device number '01' of setting data. Then a sentence SD 01 containing a setting data request code 'SD' and a device number '01' is outputted to the bus L. Here, the device 1 receives the code 'SD' and number '01' and transmits the expression of data including its device number '01' and setting data 'X...Y...' to the bus L. Then the device 4 receives data information regarding the number '01' and grasps and displays the setting data that the device 1 has. The device 5, on the other hand, quits requesting the transmission device of information once receiving this code having priority.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transmitting data such as a process amount.

[0002]

2. Description of the Related Art Conventionally, as a data transmission method, process data such as temperature collected by a slave station is transmitted by a slave station to a master station via a transmission line in response to a polling signal from the master station. There is a polling method in which after the processing, a polling signal is transmitted to another slave station again.

[0003]

However, in the polling method, the master station is always required and the polling signal is always required, so that the apparatus is complicated, the response takes time, and the communication speed is insufficient. is there.

In addition, when many devices are connected to a transmission line, and when a certain upper device communicates with a specific lower device, it is sometimes desired that another upper device also take in the communication. is there.

In view of the above points, an object of the present invention is to provide a data transmission device having a simple structure and capable of obtaining necessary information.

[0006]

According to the present invention, there is provided a first management device for making a predetermined information request to a transmission device, and a signal output from the transmission device to a bus in response to the request from the first management device. And a second management device for receiving and receiving data.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention. In FIG. 1, for example, an input device 1, an output device 2, an arithmetic device 3, and the like as a transmission device are connected to a bus L such as a common network as a transmission line. The output device 2,..., The arithmetic device 3,. Each of these devices is assigned a device number unique to the device, and data and the like can be transmitted using this device number.

The analog signal data such as temperature input to the input device 1 is subjected to necessary processing such as linearization and the like, and is given a unique device number of the input device 1 and output to the bus L as output data. Is output.

Of the data flowing on the bus L in this way, the output device 2 and the arithmetic device 3 take in the necessary data. For this reason, these capture devices include:
A device number assigned to output data of an input device or the like required by the capture device is set in advance as a capture number depending on which input device or the like needs output data.

For example, assuming that the data of the input device 1 is fetched by the output device 2 and the arithmetic device 3, the output device 2 and the arithmetic device 3 take the same number as the device number "01" of the input device 1 and obtain the input number " 01 ".

The output device 2 matches the input number “01” of the data flowing through the bus L and corresponds to the input device 1.
Only the data with the device number "01" is discriminated and selected, taken in, and output to the outside after predetermined processing.

Further, the arithmetic unit 3 outputs the input device 1 corresponding to the acquisition number “01” of the data flowing through the bus L.
Only the data with the device number “01” is selected, determined and imported. Then, after performing other necessary calculations such as averaging, the unique device number “03” of the arithmetic unit 3 is added to the data.
And output to the bus L.

By the way, to the bus L, management devices 4 and 5 as operation display devices are connected, for example, a certain management device 4
Therefore, it is assumed that a setting data request is made to the input device 1 as the transmission device having the specific device number “01”. In this case, the setting data request code "SD" and the device number "0"
The following message including "1" is output to the bus L.

SD 01 Then, the input device 1 as a transmission device having the corresponding device number “01” receives this setting data request code “SD” and its own device number “01”, and the setting data request is sent to itself. Then, the following data including the response code “SDA”, its own device number “01” and the setting data “X ... Y ...” is transmitted and output to the bus L.

SDA 01 XXXX, YYYYYY, ... Then, the management device 4 receives and takes in the above data information for the device number “01”, grasps the setting data and the like of the input device 1, and displays it on the display means. It can be displayed and recognized by humans.

At this time, the information request code "SD" or the response code "SDA" is preliminarily agreed with the code indicating the priority, and the other management device 5 has the code "SD" or "SDA" having the priority. When it receives the message, it stops requesting information from the transmission device for a predetermined time and prevents the bus L from being congested. Examples of such information requests include a request for setting value information, a request for menu information such as explanations used when listing the contents of each device, and a data display information request for indicating alarm contents.

That is, the other management device 5 does not output data to the bus L for a predetermined time when it receives the information request code or the response code having the priority right flowing through the bus L.
Even in this case, the output device 2, the arithmetic device 3, and the like, which are other transmission devices, transmit and receive data in real time. Then, when the information having the priority right does not exist on the bus L after a predetermined time elapses, the management device 5 restarts the original data transmission / reception.

The output device 2 as another transmission device,
When the arithmetic unit 3 or the like receives the information request code or the response code having the priority flowing through the bus L, it does not output the data to the bus L for a predetermined time to prevent the bus L from being congested. May be.

The other management device 5 is the management device 4
The data output from the transmission device 1 to the bus L in response to the information request can be received and the required data can be taken in, and the management device 5 can maintain the same contents as the management device 4.

The data that can be taken in by the management device 5 can be data that is output in response to an information request from another management device, regardless of whether it is given priority or not.

[0021]

As described above, according to the present invention, there is provided the first management device for making a predetermined information request to the transmission device and the first management device.
And a second management device that receives and outputs the data output from the transmission device to the bus in response to the request from the management device. For this reason, the main master station is not required, the communication speed can be made sufficiently high, and the configuration with only a minimum of two devices and a bus can combine dozens or hundreds of data and devices as long as the number allows. Can be configured easily, arbitrarily, and flexibly, and can be easily and sufficiently flexible for various systems.
It is highly scalable and can respond effectively and efficiently. In addition, since data is exchanged preferentially between the management device and a specific transmission device, the bus is not congested, reliable transmission can be performed quickly, and data information required by other management devices can be obtained. Since it is possible to reliably obtain and import the contents, it is possible to maintain the sameness of the contents held by each management device, or to give a unique function to each management device and perform setting, operation, display, etc. It is extremely user-friendly, easy for anyone to use, flexible, flexible and reliable.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view showing one embodiment of the present invention.

[Explanation of symbols]

 1 Input device 2 Output device 3 Arithmetic device 4, 5 Management device L bus

Claims (1)

[Claims] 1. A first management device which requests a predetermined information from a transmission device, and a second management device which receives and fetches data output from the transmission device to a bus in response to a request from the first management device. And a management device for the data transmission device.