JPH03265238A - Communication equipment - Google Patents

Abstract

PURPOSE:To improve the reliability of received information by requesting retransmission to a 1st control means via a signal line from a 2nd control means when a reception error takes place only in the 2nd control means in the normal state of the 1st control means and allowing the 1st control means to raise an output. CONSTITUTION:Information Dr from an external device 9 is given to main and sub CPUs 2, 3 and stored respectively in main and sub RAMs 4, 5. A relay 6 is normally thrown to the position that an output of the main CPU 2 is sent to the external device 9 as information Dt. When the main CPU 2 is faulty, an output of the sub CPU 3 is sent to the external device 9 as the information Dt. The CPUs 2, 3 are connected by signal lines 7, 8 and the sub CPU 3 gives a retransmission request to the main CPU 2 via the signal line 7 when a reception error takes place in the sub CPU. The main CPU 2 requests retransmission to the external device 9. Thus, runaway of the program of the sub CPU 3 due to reception error is prevented and occurrence of difference between contents of the main and sub memories 4, 5 is prevented and the reliability of received information is considerably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a communication device that transmits and receives data and includes a memory for backing up received data.

Conventional technology Traditionally, in communication devices that transmit and receive data,
It is configured to include a control section that performs communication control and data processing, and a memory that stores reception data received by the control section. Further, in case the control section becomes abnormal, a sub-control section and a backup memory are provided. Therefore, when receiving data, the control section and the sub-control section each receive the data and store the data in the memory and the backup memory, respectively. When transmitting data, data is transmitted from the control section when the control section is in a normal state, and data is transmitted from the sub-control section when the control section is in an abnormal state.

In this way, the received data can be supplied to the control unit and the sub-control unit in parallel, but the data output from the control unit and the sub-control unit cannot be transmitted in parallel. Normally, a switch is required.
The switching device is connected to the control section, and when the control section side is in an abnormal state, it is connected to the sub-control section side.

Problems to be Solved by the Invention FIG. 3 is a flowchart for explaining a data receiving operation in a conventional communication device.

When data is received from, for example, an external computer in step b1, the control unit determines whether a reception error has occurred in step b2. If no reception error has occurred, the process proceeds to step b3, where the sub-control unit determines whether or not a reception error has occurred. If no reception error occurs in the sub-control unit,
Ends the reception operation.

If a reception error occurs in the control section in step b2, the process proceeds to step b4. In step b4, a retransmission request signal is transmitted from the control unit to the external computer, and when the external computer receives the retransmission request signal, the communication device that transmits data again transmits data in step b1. and receive data from the external computer again.

If the determination in step b3 is affirmative, that is, if no reception error occurs in the control unit but a reception error occurs in the sub-control unit, the retransmission request signal cannot be transmitted to the external computer. In other words, since the control unit is in a normal state, the switching device is connected to the control unit, and the retransmission request signal output from the sub-control unit is not sent to the outside. Therefore, the contents of the memory on the control unit side There is a problem that there is a difference between the contents of the backup memory and the contents of the backup memory on the sub-control unit side, and the backup memory does not function as a backup memory.

An object of the present invention is to provide a communication device that can solve the above technical problems and significantly improve the reliability of received data.

Means for Solving the Problems The present invention provides first and second control means for transmitting and receiving data and outputting a retransmission request signal when a reception error occurs during data reception; a signal line connecting the first and second control means; When a reception error occurs only in the second control means when the control means is normal, the second control means transmits a retransmission request signal to the first control means via the signal line, and the first control means outputs the retransmission request signal. This is a communication device characterized by:

According to the present invention, when receiving data, the first and second control means each receive the data, and when transmitting data, the transmitting means controls the first control means when the first control means is normal. The output of the means is transmitted, and when the first control means is abnormal, the output of the second control means is transmitted. That is, when the first control means is normal, the first control means performs data transmission and reception operations, and the second control means is used for backing up received data.

The first and second control means output a data retransmission request signal when a reception error occurs during data reception. Therefore, when a reception error occurs in the first control means when the first control means is normal, a retransmission request signal is output from the first control means. Also,
When a reception error occurs only in the second control means, the second control means transmits a retransmission request signal to the first control means via the signal line, and the first control means outputs the retransmission request signal.

Therefore, even if a reception error occurs only in the second control means when the first control means is normal, a data retransmission request signal is sent, and the same data is received by the first and second control means again. will be done. This makes it possible to effectively use the second control means for backing up the received data, thereby significantly improving the reliability of the received data.

Embodiment FIG. 1 is a block diagram showing the basic structure of a communication device 1 according to an embodiment of the present invention. The communication device 1 includes a main control unit 2 and a sub-control unit 3 that each receive data from an external device 9 such as a personal computer, and a main memory 4 that stores data received by the main control unit 2 and the sub-control unit 3, respectively. It is configured to include a sub memory 5, and a relay 6 that switches and outputs the outputs from the main control section 2 and the sub control section 3.

Data Dr from the external device 9 is sent to the terminal RD of the main control unit 2.
I and the terminal RD2 of the sub-control unit 3. C.P.
U (Central Processing Uni)
t) etc., the main control unit 2 realizes the received data D.
r is stored in main memory 4 realized by random access memory or the like. Similarly, the sub-control unit 3, which is implemented by a CPU or the like, stores the received data Dr in the sub-memory 5, which is implemented by a random access memory or the like. The terminal TD1 of the main control section 2 is connected to the terminal 6a of the relay 6, and the terminal TD2 of the sub-control section 3 is connected to the terminal 6b of the relay 6.
C is electrically connected, and the output from the main control section 2 is transmitted to the external device 9 as data Dt. When the main control section 2 is in an abnormal state, the relay 6 connects the terminal 6b and the terminal 6C, and outputs the output from the sub-control section 3 to the external device 9 as data Dt.

The main control section 2 and the sub-control section 3 are interconnected by a signal line 7.8. The sub-control unit 3 is connected to the signal line 7
When a reception error occurs in the sub-control unit 3, a retransmission request signal is transmitted to the main control unit 2 via the sub-control unit 3.

The relay 6 may be switched manually when the operator of the communication device 1 determines that the operating state is abnormal, or the relay 6 may be switched manually when the operator of the communication device 1 determines that the operating state is abnormal. The switching signal may be transmitted to the control unit 2 and automatically performed by a switching signal from the sub-control unit 3 when there is no response to the specific signal.

FIG. 2 is a flowchart for explaining the data receiving operation in the communication device 1. As shown in FIG. In step a1, when the data Dr from the external device 9 is received, the main controller 2 determines whether a reception error has occurred in the main control unit 2 in the stainless steel 7a2. If no reception error has occurred, the process proceeds to step a3, where the sub-control unit 3 determines whether or not a reception error has occurred. If the determination in step a3 is negative, that is, if no reception error has occurred in either the main control section 2 or the sub-control section 3, the reception operation is ended.

In step a2, if a reception error occurs in the main control section 2, the process proceeds to step a4, and a retransmission request signal is outputted from the main control section 2 to the external device 9. When this retransmission request signal is received by the external device 9, the external device 9
transmits the data Dr again to the communication device l. The communication device 1 returns to step a1 and starts the data reception operation again.

If the determination in step a3 is affirmative, that is, no reception error has occurred in the main control section 2, but a reception error has occurred only in the sub-control section 3, the process proceeds to step a5.6 In step a5, the sub-control section 3 outputs a retransmission request signal to the main control section 2.

Thereafter, in step a4, the main controller 2 transmits a retransmission request signal to the external device 9. When this retransmission request signal is received by the external device 9, the external device 9 again transmits 5 data Dr to the communication device 1, and the communication device 1 returns to step at and starts the data receiving operation again. .

As described above, according to this embodiment, if a reception error does not occur in the main control section 2 and a reception error occurs only in the sub-control section 3, the sub-control section 3 transmits the retransmission request signal to the main control section 2. Based on this retransmission request signal, the main control unit 2
transmits a retransmission request signal to the external device 9. Therefore, it is possible to prevent the so-called program runaway of the sub-control unit 3 from occurring due to a reception error, and also to prevent a difference between the contents of the main memory 4 and the contents of the sub-memory 5. This greatly improves the reliability of received data.

Although the present invention has been described as a communication device that transmits and receives data with an external device, the present invention may be implemented when transmitting and receiving data within one device. For example, the present invention may be implemented in a light control device that controls the dimming level of lighting used on a stage or the like.

The dimmer device includes a dimmer console that is equipped with a preset fader, crossfader, etc., and a dimmer unit that controls the dimming level of the lighting. Send data to the dimming unit to control the dimming level of the lighting. :a The optical operator console and the light control unit each include a control section such as a CPU, and data is transmitted and received between these control sections.

Therefore, by implementing communication W1 of the present invention within the dimming unit, the reliability of the dimming level data received by the dimming unit is improved.

Effects of the Invention As described above, according to the present invention, even if a reception error occurs only in the second ivI control means when the first control means is normal, a data retransmission request signal can be transmitted.
Again, the same data will be received by the first and second control means. This makes it possible to effectively use the second control means for backing up the received data, thereby significantly improving the reliability of the received data.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of a communication device 1 which is an embodiment of the present invention, FIG. 2 is a flowchart for explaining the reception operation in the communication device 1, and FIG. It is a flowchart for explaining reception operation.

Claims (1)

[Claims] First and second control means that transmit and receive data and output a retransmission request signal when a reception error occurs during data reception; and a first control means when the first control means is normal. transmitting means for transmitting the output of the second control means when the first control means is abnormal; and a signal line connecting the first and second control means; When a reception error occurs only in the second control means, the second control means transmits a retransmission request signal to the first control means via the signal line, and the first control means outputs the retransmission request signal. Characteristic communication device.