JPS63266945A - Data communication equipment - Google Patents

Abstract

PURPOSE:To prevent the execution of real time control by means of old data resident in a master station by adding resident information to a data resident from a slave station and sending the result after the restoration of a fault in a line or the like. CONSTITUTION:If a communication line 8 is opened due to any failure, the status mode of an information control circuit 4 of a slave station 2 is changed into the resident mode. When the open line 8 is restored afterward, the slave station 2 reads the transmission data from an information storage circuit 7 and uses a resident information provision means 4a so as to add the resident information to the transmission data and sends the result to a master station 1. When all the transmission data resident in the storage circuit 7 are sent, the information control circuit 4 is switched to the normal mode. On the other hand, the master station 1 discriminates the resident information added to the received data by a discrimination means 4b and applies the processing to the received data added with the resident information as the old data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data communication device for transmitting and receiving all kinds of data such as telephone, facsimile, and image information.

[Prior Art] FIG. 4 is a block diagram showing the configuration of this type of conventional data communication device. In the figure, 1 is a master station that transmits and receives data (information), and 2 is a master station that exchanges data with the same master station 1. 3 is an interface circuit that transmits/receives data; 4 is an information control circuit that controls the transmission of data to be transmitted and also executes control based on the received data; 5 is a slave station that transmits and receives data; 6 is a display circuit for displaying received data in real time by the information control circuit 4, and 8 is a master station 1. Communication line between slave stations 2, 9 is reception/
This is a small recording circuit that logs transmitted data, etc.

The master station 1 is comprised of an interface circuit 3, an information control circuit 42, a line monitoring circuit 52, a display circuit 6, and a data recording circuit 9, while the slave station 2 is the master station except that it lacks the display circuit 6. It has the same configuration as 1.

Next, the operation will be explained. When transmitting data from the slave station 2 to the master station 1, the information control circuit 4 in the slave station 2 transmits the data to the master station 1 via the interface circuit 3 and the communication line 8.

The transmitted data is input to the information control circuit 4 via the interface circuit 3 in the master station 1, and is always controlled in real time by the information control circuit 4 to be displayed on the display circuit 6 or displayed on the data recording circuit 9. Processing such as recording to is performed.

Also, the main station 1. Data generated within the slave station 2 to be transmitted to the master station 1 while the communication line 8 is disconnected between the slave stations 2 is transferred to a line monitoring circuit 5 capable of detecting the disconnection state.
Depending on its function, it can be discarded immediately or simply retained.

Although only the case where data is transmitted from the slave station 2 to the master station 1 has been described above, the transmission of data from the master station 1 to the slave station 2 is performed in exactly the same manner, and the communication line 8
When the system is disconnected, data is discarded or simply stored as described above.

[Problems to be Solved by the Invention] Since the conventional data communication device is configured as described above, once the communication line 8 is temporarily disconnected due to a failure in the communication port 4IfA8, etc., the same disconnection status is prevented. ffl I13, if data that was generated and accumulated in slave station 2 (or master station 1) during that time is sent to master station 1 (or slave station 2) after recovery, this old data will be lost. Real-time control is executed at master station 1 (or slave station 2) for
tAAl1 had a problem in that even though the data was old, it was displayed on the display circuit 6 as real-time information (lamp lighting, buzzer sounding, etc.).

This invention was made in order to solve the above-mentioned problems, and it not only allows transmission data to be stored, but also makes it possible to distinguish between stored data and normal data and transmit it, so that the old data stored It is an object of the present invention to provide a data communication device that reliably prevents problems such as execution of real-time control over data.

[Means for Solving the Problems] The data communication device according to the present invention includes a line monitoring means for detecting the communication state of the communication line in each of the master station and the slave station, and a line monitoring means for detecting the communication state of the communication line. storage means for retaining transmission data when it is determined that the transmission data is in a disconnected state;
A retention information addition means for adding retention information to the transmission data when transmitting the transmission data retained in the storage means after recovery from the disconnected state of the communication line, and whether or not retention information is added to the transmitted data. The system is equipped with a determining means that can determine whether the

[Function] In the data communication device according to the present invention, when a failure (disconnection state) of the communication line is detected by the line monitoring means, the transmitted data from the time of detection until the failure is recovered is retained in the storage means, When transmitting the above transmission data after recovery from the above failure, the retained information phase is used.

The retention information is added to the transmission data by the addition means.

Then, in the master station or slave station on the receiving side, the determination means determines whether or not retention information is added to the transmitted data, and if the IF retention axis information is added, the above data is Communication processing is performed as old data, while real-time control is performed on the data if no retention information is added.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, as in the past, 1 is a master station that transmits and receives data (information), 2 is a slave station that transmits and receives data with the same master station 1,
3 is an interface circuit for transmitting/receiving data. Further, 4 is an information control circuit that controls the transmission of data to be transmitted and also executes control based on received data, and 5 is a line monitoring means that monitors the communication status of the communication line 8 via the interface circuit 3. Line 1 is a visual circuit, and 6 is a display circuit that displays received data in real time by the information control circuit 4.

Reference numeral 7 indicates an information storage circuit as a storage means for retaining transmission data when the communication line 8 is determined to be disconnected by the line monitoring circuit 5; 8 indicates the master station 1. A communication line between the slave stations 2, and a data recording circuit 9 for logging received/transmitted data and the like.

The information control circuit 4 in the device of this embodiment adds the retention information to the transmission data when transmitting the transmission data retained in the information storage circuit 7 after the communication line 8 recovers from the disconnection state, and also performs real-time control. Normal/retention information addition means 4 for adding normal information to normal transmission data
a, and determining means 4b that can determine whether retention information or normal information has been added to the transmitted data.

Note that, as in the prior art, the master station 1 has the same configuration as the slave station 2 except that it has the 1 display circuit 6.

Next, the operation of the apparatus of this embodiment will be explained with reference to FIGS. 2 and 3. When transmitting data from the slave station 2 to the master station 1, as shown in FIG. It is determined whether the state of the information control circuit 4 is the normal mode or the retention mode (step A2
), here, the status mode of the information control circuit 4 is set based on the communication status signal on the communication line 8 from the line monitoring circuit 5, and if one communication line 8 is disconnected due to some kind of failure. The data transmission stop signal from the line monitoring circuit 5 sets the system to the retention mode, while the data transmission start signal from the line monitoring circuit 5 sets it to the retention mode when it is not in a disconnected state (or after detecting recovery from the disconnected state). Set to normal mode.

If the state mode of the information control circuit 4 is the normal mode, the transmission data is read out from the information storage circuit 7, and the normal/retention information adding means 4a adds normal information (normal data to be processed in real-time control) to the transmission data. After adding a code indicating that it is (step A3), the data is transmitted to the master station 1 (step A4).

When the communication line 8 becomes disconnected due to some kind of failure, the state mode of the information control circuit 4 changes from the normal mode to the retention mode (step A5), and subsequent transmission data is stored as information until the disconnection is restored. It remains recorded in the circuit 7, that is, it remains there.

Further, when the disconnected state of the communication line 8 is restored, the transmission data is read out from the information storage circuit 7 in response to the data transmission signal from the line monitoring circuit 5, and the normal/stagnant information adding means 4a
After adding retention information (a code indicating that the data is old retention data that does not need to be processed in real-time control) to the transmitted data (step A6), the data is transmitted to the 71 station 1 (step A7), and the data is retained in the information storage circuit 7. After all of the previously transmitted data has been sent out, the state mode of the information control circuit 4 is switched from the retention mode to the normal mode (step A).
8).

On the other hand, on the master station 1 side that receives transmission data from the slave station 2, as shown in FIG.
Step B: Read the received data input through the
l) The type of the received data is determined by determining the information (retention information or normal information) added to the received data in the determining means 4b (step B2).

Regarding the received data with normal information added,
As in the past, real-time control is performed by the information control circuit 4, and the received data is subjected to processing such as display (data display, lamp lighting, LED display, etc.) in the display circuit 6 (step B3). , are logged in the information storage circuit 7 and data recording circuit 9 (step B4).

On the other hand, received data to which retention information has been added is subjected to communication processing as old data. That is, in the case of this embodiment, as shown in FIG. 3, the process moves to logging in step B4 without performing real-time control in step B3.

In this way, according to the present embodiment, retained data and non-retained data are transmitted, received, and communicated while being distinguished from each other, so that problems such as executing real-time control on old retained data can be avoided. This can definitely be prevented from occurring.

In addition, in the above embodiment, the case where data is transmitted from slave station 2 to master station 1 is explained;
Even when transmitting data to a destination, or even when there are multiple destinations, operations are performed in the same manner as described above, and the same effects as in the embodiments described above are achieved.

Furthermore, in the above embodiment, 1 normal information is added to normal data and retention information is added to retained data, but nothing is added to normal data and only retained data is added. It is also possible to add retention information and determine whether the data is normal data or retained data based on whether or not this retention information is added. In this case, the same effects as in the above embodiment can be achieved.

[Effects of the Invention] As described above, according to the present invention, when a disconnection state of a communication line is detected by the line monitoring means, the transmitted data is retained in the storage means from the time of detection until the disconnected state of the communication line is restored, and the above-mentioned transmission data is when sending data.

Since the structure is configured such that retained data can be distinguished from data that is not retained using the retention information adding means and the determination means, communication processing can be performed according to retained data or normal data, and old data that has been retained can be processed. This has the effect of reliably preventing problems such as execution of real-time control by using the system, and enabling highly accurate information transmission to operators and the like.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram showing the configuration of a data communication device according to an embodiment of the present invention, FIGS. 2 and 3 are flow charts for explaining the operation of the above embodiment, and FIG. The figure is a block diagram showing the configuration of a conventional data communication device. In the figure, 1-=master station, 2...slave station, 4a...
Normal/l station information addition means, 4b...determination means, 5--line monitoring circuit as line monitoring means, 7...
- information storage circuit as storage means; 8 - communication line; In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] In a data communication device comprising a master station and a slave station that transmit and receive data via a communication line, a line monitoring means detects the communication state of the communication line, and the line monitoring means detects when the communication line is disconnected. storage means for retaining the transmission data when it is determined that the communication line is disconnected; and retention information addition for adding retention information to the transmission data when transmitting the transmission data retained in the storage means after the disconnected state of the communication line is restored. A data communication device characterized in that each of the master station and the slave station is provided with means and determining means capable of determining whether or not retention information is added to transmitted data.