JPH10257128A - Transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the continuity of data by transmitting data to a standby system nearly at the same time when data is written in the data storing means of an on-line system. SOLUTION: When the data managing part 31 of the on-line system receives an event request signal, this event request signal is written also in the event request signal receiving memory 10 of the on-line system at the same time of the data storing memory 8 of the on-line system. The memory 10 instantly transmits the written event request signal to the data tracking transmission/ reception part 9 of the on-line system by an FIFO system. On the other hand, when the data managing part 31 of the on-line system receives a process signal, this process signal is written also in the process signal receiving memory 11 of the on-line system at the same time of the memory 8. The memory 11 similarly and instantly transmits the written process signal directly to the part 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission apparatus which is provided in a transmission system in a duplex manner, and more particularly to a transmission apparatus which can reliably guarantee data continuity when a standby system is promoted to an online system.

[0002]

2. Description of the Related Art Generally, in a facility such as a power receiving substation that requires continuous operation, a transmission system for monitoring a process in the facility has a duplex configuration in order to improve reliability and an operation rate. , An online system and a standby system.

FIG. 8 is a block diagram showing an example of a duplex transmission system using a conventional transmission device.
Is an online system, and the transmission device 1B is a standby system.

The transmission devices 1A and 1B mainly include a duplex monitoring control unit 2, a data management unit 3, and an internal device (not shown). The redundant monitoring control unit 2 monitors the abnormal state of the online system, and if an abnormality occurs and the cause of the abnormality requires switching, the online system is demoted to the standby system and the standby system is promoted to the online system. Let it.

When a status signal indicating the occurrence of an abnormality is received from an online system internal device or an external device (not shown), the online system dual monitoring control unit 2 sends a request to the online system data management unit 3 and the online system internal device. And transmits a standby system operation signal to the effect that the system operates as a standby system.
Then, an online system abnormality signal indicating that an abnormality has occurred in the online system is transmitted.

When the standby system redundant monitoring control unit 2 receives an online system abnormality signal from the online system redundant monitoring control unit 2, the standby system data management unit 3 and the internal device of the standby system operate as an online system. Is transmitted.

In this manner, the online system is demoted to the standby system, the standby system is promoted to the online system, and the state transition of the duplex transmission system is performed. Transmission device 1
A and 1B are connected to a switch 4. The switch 4 selects an online system. The online system is connected to the slave station 6 via the switch 4 and the communication line switching unit 5.

The switching of the switch 4 is performed by the communication line switching unit 5 in accordance with a switching signal transmitted by the redundant monitoring and control unit 2 when executing the state transition of the redundant transmission system. The slave station 6 transmits the input process signal to the online data management unit 3 selected by the switch 4 via the communication line switching unit 5.

The data management section 3 comprises a data transmission / reception section 7, a data storage memory 8, and a data tracking transmission / reception section 9. The online data management unit 3 receives the process signal in the data transmission / reception unit 7 and writes the process signal in the online data storage memory 8 (write refresh).

Similarly, the online data management unit 3
Receives an event request signal, such as a parameter update, from an online internal device or an external device, and writes the event request signal to the online data storage memory 8.

The online data tracking transmission / reception unit 9 receives a data tracking request from the internal device of the online system at regular intervals, and upon receiving the data tracking request, stores the contents of the data storage memory 8 of the online system. Is transmitted to the data tracking transmission / reception unit 9 of the standby system.

The standby system data storage memory 8 writes the contents stored in the online system data storage memory 8 received by the standby system data tracking transmission / reception unit 9. As described above, the online data tracking transmission / reception unit 9 transmits the contents stored in the online data storage memory 8 to the standby data tracking transmission / reception unit 9 at regular intervals, so that the duplex transmission system is in a state. At the time of transition, continuity between the storage contents of the online data storage memory 8 and the storage contents of the standby data storage memory 8 is guaranteed.

[0013]

However, in the transmission apparatus of the above-described duplex transmission system, when the online data storage memory 8 performs writing, and the online data tracking transmission / reception section 9 transmits the online data, The transmission time of the contents stored in the storage memory 8 is completely asynchronous, and the online data storage memory 8
In the period from the time when the data is written to the time when the online data tracking transmission / reception unit 9 transmits the contents stored in the online data storage memory 8, the contents stored in the online data storage memory 8 and the standby system Is different from the storage content of the data storage memory 8 of the first embodiment, and the continuation of the storage content of the online data storage memory 8 and the storage content of the standby data storage memory 8 when the state of the duplex transmission system changes. There is a problem that is not ensured.

The present invention has been made in view of the above circumstances, and is intended to provide continuity between the data held by the online data memory and the data held by the standby data memory even when the state transition of the redundant transmission system occurs. It is an object of the present invention to provide a transmission device that can reliably guarantee the transmission.

[0015]

In order to achieve the above object, an invention corresponding to claim 1 is provided in a duplex transmission system so as to be switchable as an online system or a standby system. In a transmission device in which the data is written to the data memory immediately, and in the case of the standby system, the data is written to the data memory via the online transmission process, the data to be written to the data memory is written almost simultaneously with the data memory, and the data is temporarily stored. And a transmitting / receiving means for transmitting data held in the temporary storing means to the standby system when the device is an online system, and for writing data received from the online system to a data memory when the device is a standby system. A transmission device comprising:

Accordingly, the invention according to claim 1 is characterized in that, when the data memory writes data, the transmission / reception means transmits the data to the standby system almost simultaneously with the writing of the data. The continuity of the data held in the data memory can be guaranteed between the and the standby system.

According to a second aspect of the present invention, the duplex transmission system is provided so as to be switchable as an online system or a standby system. In the online system, given data is immediately written to a data memory. In a transmission device in which data is written to a data memory through an online transmission process, a data to be written to the data memory is received at a preceding stage of the data memory, and temporary storage means for temporarily holding the data, At the same time, when the data held in the temporary storage unit is written to the data memory, the data held in the temporary storage unit is transmitted to the standby system at the same time as the standby system. Transmission comprising transmission / reception means for writing data to a data memory It is the location.

Therefore, according to the invention corresponding to claim 2, since the data held in the temporary storage means is written by the data memory and simultaneously transmitted by the transmission / reception means, the invention is further improved than the invention corresponding to claim 1. Data continuity in the data memories of both systems can be guaranteed.

Further, according to a third aspect of the present invention, in the transmission apparatus according to the first or second aspect, a checksum value generating means for generating a checksum value of the data held in the data memory is added. The transmitting and receiving means has a function of transmitting and receiving the checksum value generated by the checksum value generating means, and outputs the checksum value generated by the checksum value generating means and the checksum value received by the transmitting and receiving means. This is a transmission device to which a checksum detecting means for detecting a data abnormality is added based on the data.

According to a third aspect of the present invention, in addition to the operation of the first or second aspect, the checksum detecting means includes a data stored in the online data memory and a standby data memory. , A temporary inconsistency due to some cause is detected between the data and the data stored in the data, and thereby an abnormality can be detected.

Further, the invention corresponding to claim 4 is:
4. The transmission apparatus according to claim 3, wherein the checksum detection means has a checksum value generation function for generating a checksum value of the data held in the data memory, and the checksum generated by the checksum value generation function. This is a transmission device that performs detection based on the sum value.

Therefore, the invention according to claim 4 is characterized in that the checksum detecting means transmits and receives the checksum value generated by the checksum value generating function itself, the checksum value generated by the checksum value generating means, Since the means detects the data abnormality based on the received checksum value, the abnormality can be detected more reliably than the invention according to claim 3.

According to a fifth aspect of the present invention, in the transmission apparatus according to the third or fourth aspect, when the checksum detection means detects an abnormality in the data, and when the checksum detecting means is an online system, the data memory is used. Is a transmission device that transmits all data held in the standby system to the standby system and writes all data received from the online system to the data memory of the standby system when itself is the standby system.

Therefore, the invention corresponding to claim 5 writes all data held in the online data memory into the standby data memory when the checksum detecting means detects an abnormality. Continuity can be guaranteed even if a temporary inconsistency occurs between the data held in the data memory and the data held in the standby data memory for some reason.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing an example of a duplex transmission system using a transmission device according to the present embodiment. The same parts as those in FIG. Here, only different portions will be described in detail.

That is, the transmission apparatus according to the present embodiment transmits the event request signal or the process signal to the standby system almost simultaneously with the writing of the event request signal or the process signal in the online system in order to ensure the continuity of data. Specifically, as shown in FIG. 1, the data management unit 31 has an event request signal reception memory 10 at a stage preceding the data tracking transmission / reception unit 9, and transmits data tracking data to the data transmission / reception unit 7. A process signal receiving memory 11 is provided between the transmitting and receiving unit 9.

Here, the event request signal reception memory 10
Is for writing an event request signal received from an internal device or an external device, and immediately transmitting the event request signal to the data tracking transmission / reception unit 9 by a FIFO method.

Similarly, the process signal reception memory 11
A process signal received from an internal device or an external device is written, and the process signal is immediately transmitted to the data tracking transmission / reception unit 9 by a FIFO method.

Next, the operation of such a transmission device will be described. When the online data management unit 31 receives the event request signal, the event request signal is written to the online event request signal reception memory 10 at the same time as the online data storage memory 8. The online event request signal reception memory 10 immediately transmits the written event request signal to the online data tracking transmission / reception unit 9 by the FIFO method.

On the other hand, similarly, when the online data management unit 31 receives the process signal, the process signal is written into the online process signal receiving memory 11 simultaneously with the online data storage memory 8. The online process signal reception memory 11 immediately transmits the written process signal to the online data tracking transmission / reception unit 9 by the FIFO method.

The online data tracking transmission / reception section 9 is provided with an online event request signal reception memory 1.
The event request signal received from 0 or the process signal received from the online process signal reception memory 11 is transmitted to the standby data tracking transmission / reception unit 9.

The data tracking transmission / reception section 9 of the standby system is provided with the data tracking transmission / reception section 9 of the online system.
And writes the event request signal or the process signal received from the data storage memory 8 of the standby system.

As described above, when the transmission system is duplexed by the transmission apparatus according to the present embodiment,
The event request signal written by the online data storage memory 8 is simultaneously sent to the event request signal reception memory 10.
Similarly, the process signal written in the online data storage memory 8 is also written in the process signal reception memory 11 at the same time, and is immediately transmitted through the online and standby data tracking transmission / reception units 9 by the FIFO method. The data is transmitted and written to the data memory 8 of the standby system.

Therefore, even if the state transition of the duplex transmission system occurs, continuity between the storage contents of the online data storage memory 8 and the storage contents of the standby data storage memory 8 can be ensured.

(Second Embodiment) FIG. 2 is a block diagram showing an example of a data management unit 31 of a transmission apparatus according to the present embodiment. The same parts as those in FIG. The description thereof will be omitted, and only different portions will be described in detail.

That is, the transmission apparatus according to the present embodiment preferentially processes an event request signal or a process signal having important contents in addition to the configuration of the first embodiment. As shown in FIG. 2, instead of the event request signal receiving memory 10, a high priority event request signal receiving memory 101 and a low priority event request signal receiving memory 102 are provided in parallel with each other. In place of the high priority process signal reception memory 111 and the low priority process signal reception memory 11
2 are provided in parallel with each other.

As a result, an event request signal set in advance to a high priority is written in the high-priority event request signal reception memory 101 in accordance with the function, processing content, tracking priority, and the like of the event request signal. An event request signal set to a low priority in advance is written in the low priority event request signal reception memory 102.

Similarly, a process signal set to a high priority in advance is written in the high-priority process signal reception memory 111, and the low-priority process signal reception memory 112 is written in the high-priority process signal reception memory 112.
Is written with a process signal set to a low priority in advance.

When the online data management unit 31 receives the event request signal, the event request signal is written into the data storage memory 8 and, at the same time, according to the priority, the online high-priority event request signal reception memory 101. Or low priority event request signal reception memory 1
02 is written. The written event request signals are first written in the high priority event request signal reception memory 101 for high priority, and the data tracking transmission / reception unit 9 of the online system is started by the FIFO method.
Sent to.

Similarly, when the on-line data management unit 31 receives the process signal, the process signal is written into the data storage memory 8 and, at the same time, the on-line high-priority process signal reception is performed according to the priority. Memory 111 or process signal reception memory 11 for low priority
2 is written. The written process signal is transmitted to the online data tracking transmission / reception unit 9 by the FIFO method, starting from the one written in the high-priority process signal reception memory 101 for high priority.

When receiving the event request signal or the process signal, the online data tracking transmission / reception section 9 transmits the event request signal or the process signal reception to the standby data tracking transmission / reception section 9. The standby data tracking transmission / reception unit 9
The event request signal or the process signal received from the online data tracking transmission / reception unit 9 is written to the standby data storage memory 8.

As described above, in the transmission apparatus according to the present embodiment, the high priority event request signal reception memory 1
01 and a low priority event request signal reception memory 102 in parallel, and a high priority process signal reception memory 111
And the low-priority process signal reception memory 112 are provided in parallel, so that the same effect as that of the transmission device according to the first embodiment can be obtained.

The data tracking transmission / reception section 9 of the online system transmits the event request signal or the process signal of the higher priority first. In, continuity can be guaranteed for stored contents having a higher priority.

The transmission apparatus according to the present embodiment includes two event request signal reception memories 101 and 102 and two process signal reception memories 111 and 112. However, the present invention is not limited to this. The same effect can be obtained with the number of.

The timing at which the online data tracking transmission / reception unit 9 receives the event request signal or the process signal can be adjusted to various states according to the priority for each signal. For example, this timing may be set in a short cycle in proportion to the priority, or may be set uniformly.

(Third Embodiment) FIG. 3 is a block diagram showing an example of a data management section 3 of a transmission apparatus according to the present embodiment. The same parts as those in FIG. The description thereof will be omitted, and only different portions will be described in detail.

That is, the transmission apparatus according to the present embodiment ensures the continuity of data even more reliably in addition to the configuration of the first embodiment.
As shown in the figure, the event request signal reception memory 1 is provided before the data storage memory 8 and the data tracking transmission / reception unit 9.
0, and the data transmitting / receiving unit 7 and the data storage memory 8
, A process signal reception memory 11 is provided.

Thus, when the online data management unit 3 receives the event request signal, the event request signal is first written into the online event request signal reception memory 10. The written event request signal is immediately transmitted to the online data storage memory 8 and the online data tracking transmission / reception unit 9 by the FIFO method.

Similarly, when the online data management unit 3 receives a process signal, the process signal is first written into the online process signal reception memory 11. The written process signal is immediately transmitted to the online data storage memory 8 and the online data tracking transmission / reception unit 9 by the FIFO method.

Here, in the transmission apparatus according to the first and second embodiments described above, the event request signal in the waiting state is stored in the online event request signal reception memory 10 or the online process signal reception memory 11. A case will be described in which the state transition of the duplex transmission system is performed while the process signal is being written. That is, even if the event request signal or the process signal has been written to the data storage memory 8, the online data tracking transmission / reception unit 9 from the online event request signal reception memory 10 or the online process signal reception memory 11. May not have been sent to. For this reason, continuity between the storage contents of the online data storage memory 8 and the storage contents of the standby data storage memory 8 may not be guaranteed.

However, in the transmission apparatus according to the present embodiment, the event request signal reception memory 1 is provided before the data storage memory 8 and the data tracking transmission / reception section 9.
0 and a process signal reception memory 11, and the event request signal or the process signal written in the online data storage memory 8 is simultaneously transmitted via the online and standby data tracking transmission / reception units 9, and Since the data is also written to the data storage memory 8 of the system, even if there is an event request signal or a process signal in a waiting state, the contents stored in the data storage memory 8 of the online system and the data stored in the data storage memory 8 of the standby system are compared. Continuity can be guaranteed.

(Fourth Embodiment) The transmission apparatus according to the present embodiment is obtained by adding a sum check mechanism to the transmission apparatuses according to the first to third embodiments. Less than,
The case where the transmission device according to the third embodiment is provided with a mechanism for sum check will be described as an example.

FIG. 4 is a block diagram showing an example of the data management unit 3 of the transmission apparatus according to the present embodiment, and FIG.
FIG. 4 is a conceptual diagram showing an example of a sum check of an event request signal. The same parts as in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described in detail.

That is, in the transmission device according to the present embodiment, the data area 14 in which data such as an event request signal and a process signal is stored in the data storage memory 81.
And a checksum value area 15 for storing a checksum value of each data in the data area.

The checksum value area 15 is a storage unit in which a checksum value can be written from the checksum value generation units 121 to 123 and a checksum value can be read from the checksum value detection unit 13. They may be arranged in a concentrated manner in the element or a specific area, or may be arranged in a distributed manner. However, it is preferable from the viewpoint of specifying and isolating an abnormal part that the data be provided for each predetermined management unit, for example, for each data group unit. In addition, as a management unit of each data, for example, a process processing unit such as a power receiving and transforming facility, a functional unit such as an intake pump system and a water distribution pump system, or an installation region unit of the slave station 6 which is a machine to be processed is used. Applicable.

The checksum value generation units 121 to 123
When an event request signal or a process signal is received from an internal device or an external device, the storage content is read from the data area 14 of the data storage memory 81, and the storage content of the data storage memory 81 and the received event request signal or process are read. It has a function of generating a checksum value from the signal and writing the checksum value to the checksum area 15 of the data storage memory 81.

The checksum detector 13 compares the respective checksum values generated by the checksum value generators 121 to 123 corresponding to the respective signals, and based on the comparison result, stores the contents of the data storage memory 81. It has a function to check the validity of

With the above configuration, the event request signal is written to the online data storage memory 81 and transmitted to the online event checksum value generator 121 as shown in FIG. .

The online-system event checksum value generation unit 121 includes an online-system data storage memory 81.
Of the data area 14, a checksum value is generated from the stored contents of the data area 14, and the checksum value area 1 of the online data storage memory 81 is read.
Write 5

At the same time, the event request signal is transmitted to the standby data tracking transmission / reception unit 9 via the online data tracking transmission / reception unit 9.

The event request signal transmitted to the standby-system data tracking transmission / reception unit 9 is written into the standby-system data storage memory 81, and at the same time, the standby-system tracking checksum value generation unit 12
3 is sent.

The tracking checksum value generation unit 123 for the standby system reads out the storage contents of the data area 14 of the data storage memory 81 of the standby system, generates a checksum value from the storage contents of the data area 14, and generates the checksum value. Is written to the checksum value area 15 of the data storage memory 81.

The tracking checksum value generator 123 for the standby system is transmitted to the checksum detector 13 for the online system via the data tracking transmitting / receiving unit 9 for the standby system and the online system.

On-line checksum detector 13
Reads out the stored contents of the data area 14 of the online data storage memory 81, generates a checksum value, and writes the generated checksum value to the checksum area 15 of the online data storage memory 81. The checksum value is compared with the checksum value transmitted from the standby system, and if they match, it is determined that the data storage memory 81 of the standby system is normal. If they do not match, it is abnormal. Then, all the contents stored in the online data storage memory 81 are written to the standby data storage memory 81 via the data tracking transmission / reception units 9.

When the process signal is transmitted, the only difference is that the process checksum value generation unit 122 operates instead of the event checksum value generation unit 121, and the same operation is performed. Therefore, the description is omitted here.

As described above, in the transmission apparatus according to the present embodiment, checksum value generation sections 121 to 123 generate a checksum value, and checksum detection section 13
Online and standby data storage memory 81
Of the storage contents of the data storage memory 81 of the online system and the storage contents of the data storage memory 81 of the standby system, even if a temporary inconsistency occurs for some reason, the continuity of the Can be guaranteed.

Here, the case where this embodiment is applied to the transmission apparatus according to the third embodiment has been described as an example. However, the present invention is not limited to this, and the first or second embodiment is not limited thereto. A similar effect can be obtained by applying the same to the transmission device according to the embodiment.

As shown in FIG. 6, the contents of the process processing, for example, for each function of the power receiving and transforming equipment system, the intake pump system, the water distribution pump system, or the installation area of the slave station which is the process target equipment. The data area 14 is divided into a plurality of areas, and the checksum values corresponding to the respective data areas 14 are written into the plurality of checksum value areas 15, so that even if a temporary inconvenience occurs for some reason,
The incompatible range between the storage contents of the online data storage memory 81 and the storage contents of the standby data storage memory 81 can be minimized.

Further, when a plurality of data areas 14 are provided, as shown in FIG.
5 may be written to another storage memory 16, and FIG.
As shown in (b), the data may be written to a specific area of the data storage memory 81.

Furthermore, in the present embodiment, the case has been described where the abnormality of the storage contents of the standby data storage memory 81 is detected by the online checksum detector 13, but the present invention is not limited to this. .

For example, the checksum value generated in the online system is transmitted to the checksum detection unit 13 in the standby system via the data tracking transmission / reception unit 9 in the online system and the standby system. Then, the standby-system checksum detector 13 reads the storage contents of the data area 14 of the standby-system data storage memory 81, generates a checksum value, and compares the generated checksum value with the standby-system data storage memory. The checksum value written in the checksum value area 15 of the data storage unit 81 is compared with the checksum value generated in the online system.
May be determined to be normal, and if they do not match, it may be determined to be abnormal and all of the contents stored in the online data storage memory 81 may be written to the standby data storage memory 81.

In addition, in the transmission device according to the present embodiment, the checksum value generation unit 12 reads out all data in the updated data area 14 and generates a checksum value, but the present invention is not limited to this. Instead, the checksum value may be calculated by the following equation (1).

M = ki + j (1) m: Generated checksum value (checksum value area 15
K: Read checksum value (Checksum value area 1)
(Value written in 5) i: Value of data before writing j: Value of data after writing In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0074]

As described above, according to the present invention, the data is transmitted to the standby system almost at the same time that the data is written to the online data storage means, so that the state transition of the duplex transmission system can be achieved. In addition, it is possible to provide a transmission device that can reliably guarantee continuity between data held by an online data storage unit and data held by a standby data storage unit.

Also, since the checksum detecting means detects an abnormality using the checksum value generated by the checksum value generating means, the data held by the online data storing means and the data held by the standby data storing means are held. Even if there is a temporary inconsistency due to some cause between the data and the data to be processed, an abnormality can be detected and continuity can be guaranteed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a duplex transmission system using a transmission device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a data management unit of a transmission device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing an example of a data management unit of a transmission device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing an example of a data management unit of a transmission device according to a fourth embodiment of the present invention.

FIG. 5 is an exemplary conceptual diagram showing an example of a sum check according to the embodiment;

FIG. 6 is a conceptual diagram showing an example of a sum check when a plurality of data areas and checksum value areas are provided according to the embodiment;

FIG. 7 is a conceptual diagram showing a state example of a data storage memory when a plurality of data areas and checksum value areas are provided according to the embodiment;

FIG. 8 is a block diagram showing an example of a duplex transmission system using a conventional transmission device.

[Explanation of symbols]

 1A, 1B ... Transmission device 2: Duplex monitoring control unit 3, 31 ... Data management unit 4: Switch 5 ... Communication line switching unit 6 ... Slave station 7 ... Data transmission / reception unit 8, 81 ... Data storage memory 9 ... Data tracking transmission / reception unit 10, 101, 102 ... event request signal reception memory 11, 111, 112 ... process signal reception memory 12, 121 to 123 ... checksum value generator 13 ... checksum detector 14 ... data area 15 ... checksum value area 16 ... Different storage memory

Claims (5)

[Claims] 1. A redundant transmission system is provided so as to be switchable as an online system or a standby system. In an online system, given data is immediately written to a data memory. In a standby system, the data is transmitted through an online transmission process. A transmission device that writes data to be written to the data memory almost simultaneously with the data memory and temporarily stores the data; and a temporary storage device when the device is online. A transmitting / receiving means for transmitting the data held in the means to the standby system, and for writing the data received from the online system to the data memory when the device is the standby system. 2. A redundant transmission system is provided so as to be switchable as an online system or a standby system. In an online system, given data is immediately written to a data memory. In a standby system, the data is transmitted through an online transmission process. A transmission device that receives data to be written to the data memory at a preceding stage of the data memory and temporarily stores the data; and Almost at the same time that the data held in the storage means is written to the data memory, the data held in the temporary storage means is transmitted to a standby system. Transmitting and receiving means for writing to the data memory. Transmission apparatus according to symptoms. 3. The transmission device according to claim 1, further comprising: a checksum value generation unit that generates a checksum value of the data held in the data memory; It has a function of transmitting and receiving the checksum value generated by the sum value generating means. Based on the checksum value generated by the checksum value generating means and the checksum value received by the transmitting and receiving means, data is transmitted. A transmission device characterized by adding a checksum detecting means for detecting an abnormality of the transmission. 4. The transmission device according to claim 3, wherein said checksum detection means has a checksum value generation function of generating a checksum value of the data held in said data memory, A transmission device, wherein the detection is performed based on a checksum value generated by a generation function. 5. The transmission device according to claim 3, wherein when the checksum detection unit detects an abnormality in the data, when the checksum detection unit is an online system, all the data held in the data memory are transmitted. A transmission apparatus for transmitting data to a standby system and writing all data received from the online system to a data memory of the standby system when the transmission device is the standby system.