JPH07203565A - Command communicating system - Google Patents

Abstract

PURPOSE:To improve the reliability of command communication by providing data for check in a command to be transmitted repeatedly, and changing the data for check every transmission in conformity with the order of a rule determined beforehand. CONSTITUTION:When the command of a first time is received, a check code 0B is detected, and following this, the pointer of a data table is turned to the position of 0B. When the command of a second time is received, the pointer is shifted to the next position and 0D is called out. Then, it is judged whether or not the check code of the received command matches 0D. At a receiving side, the judgement of the command received in succesion is executed one after another, and the number of times of matching to consider the command to be the correct one is set beforehand on a program. Accordingly, the check data of the command transmitted repeatedly is changed successively every transmission, and there is little possibility that the command to be changed in conformity with a prescribed rule appears suddenly from the outside, and the reliability of the command communication is improved at this rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a command communication system used in remote control and the like.

[0002]

2. Description of the Related Art Remote control has come to be frequently performed to control devices such as a television receiver, a VTR, and an air conditioner from a distance. As the number of devices equipped with such a remote control increases, it becomes necessary to prevent interference. This is because if interference occurs, for example, although the user intends to remotely control the television receiver, the air conditioner will be controlled.

Conventionally, in order to prevent interference (and thus malfunction),
As a method adopted, there is a method in which a part of data is given in the form of parity. Further, there is also one that determines a control signal only when a command is repeatedly transmitted several times at a certain interval. In addition, some code is designed to repeatedly send a part of the code having a logic inversion relation.

[0004]

However, in the first method, when a large amount of data such as a recording channel, a start time, an end time, a date, etc. is required such as a VTR reservation, a long data is stored. Since it must be sent, if a part of the data is taken, it may match the control signal of another device or the parity may match.

Further, even in the second and third systems, if the receiving side happens to receive the same code from another, it is determined as a remote control signal of the receiving device, and a malfunction occurs. There was a drawback.

An object of the present invention is to provide a command communication system which can eliminate such drawbacks and enhance the reliability of remote control and the like.

[0007]

In order to achieve the above object, in the command communication system of the present invention, a command transmitted repeatedly a plurality of times includes check data, and the check data is previously stored every time the command is transmitted. It is designed to change in the order according to the rules established between transmission and reception.

Further, in the command communication system of the present invention, a command transmitted repeatedly a plurality of times includes a data sequence and a parity data sequence, and the parity data sequence is repeated every time the command is repeated in a predetermined order between transmission and reception. The check data is obtained from the check data and the data string, and the check data is not transmitted, and the receiving side determines the authenticity of the command from the received parity data string.

[0009]

With this structure, the receiving side may detect the check data repeatedly sent and determine whether or not the check data has changed according to a predetermined rule. In this way, the check data of the command that is repeatedly sent changes sequentially with each transmission, and although the change complies with the prescribed rules, it is unlikely that it will happen accidentally from others, and the reliability of command communication is improved accordingly. To do.

Further, the above check data is not transmitted,
Instead, in the method of transmitting the parity data string obtained from the check data and the data string, since the check data can be calculated from the received data string and the parity data string, it can be said that the check data has been substantially received. Similar processing can be performed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a remote control transmitter for a television receiver, 1 is a transmission controller including a microcomputer, 2 is a key matrix, 3 is an LED (light emitting diode) that emits infrared light,
Reference numeral 4 is a transistor for driving an LED.

The key matrix 2 turns on / off the power of the device.
Keys for FF, switching channels, and changing volume are provided. Then, when those keys are pressed, the command data shown in FIG. 3 is output from the microcomputer.

The custom code 5 represents the type of equipment such as a television receiver, VTR, air conditioner (in this case, a television receiver), and the check code 6
Is a code for specifying the remote control signal, function data 7 is data relating to functions such as channel switching and volume adjustment, and parity data 8 is a custom code 5, check code 6, and exclusive of function data 7. It is an OR. It should be noted that each of these codes and data is 8 bits, which makes a total of 32 bits.

The command of FIG. 3 is repeatedly output as long as the key is pressed. FIG. 4 shows a state of repeated output. The feature of this embodiment is a check code 6.
Is regularly changed every time a command is transmitted, that is, OB → OD → FE .... This check code is fetched from the data table (FIG. 6) in the program ROM in the transmission controller 1.

FIG. 5 shows a flow chart of command generation processing by the transmission controller 1. In the figure, it is determined in step # 5 whether or not there is a key input, and if there is, a custom code 5 is created in step # 10. Next, in step # 15, a check code is created.
When the power of the transmission controller 1 is turned on, the pointer is reset to 01 which is the initial value of the data table, but when the key is released while the power is on, the pointer position at the time of the release is held. This holding is performed by a work RAM (not shown).

In FIG. 6, the pointer is O when the last key operation is completed.
It is shown that it is held at the position B. Therefore,
In this key operation, OB is first selected as the check code. With the completion of the check code creation in step # 15, the pointer advances to the OD position. Then, in steps # 20 and # 25, the function data and the parity data are created, respectively, and the last four codes (data) are sequentially output in step # 30, and the process returns to step # 5. At this time, if the key is still pressed, steps # 5 to # 30 are repeatedly executed.

OD is selected in the second check code creation (step # 15), and FE is selected in the third check code creation. Then, when the pointer reaches the last code, it returns to the initial value 01, and cyclically selects check codes.

The command signal output in step # 30 is modulated and then output from the transmission controller 1 to drive the transistor 4. The transistor 4 turns on and off according to the command signal, and when it is on, the LED 3 is turned on. As a result, infrared light is emitted from the LED 3.

FIG. 2 shows a remote control receiving circuit provided in the television receiver. Reference numeral 10 is a receiving section for receiving infrared light, converting it into an electric signal and shaping the waveform, and 11 for receiving side. The controller. 12
Indicates a part controlled by the controller 11. The controller 11 includes a microcomputer.
The check code 6 in the received command is compared with the code in the data table built in the controller 11. This data table is also the same as that shown in FIG.

Now, among the repeat commands shown in FIG. 4, 1
When the command for the second time is received, the check code OB is detected, and accordingly, the pointer of the data table is O.
Brought to position B. When the second command is received, the pointer moves to the next position and OD is called.
Then, it is determined whether the check code of the received command matches the OD. On the receiving side, the check code of the command that is continuously received is determined one after another,
At what point (that is, how many times it matches) to determine the correct command may be set in the program.

In the above embodiment, the case where the order of the check codes is in the form of a data table on the transmitting side and the receiving side is described, but it may be a random number (function) on the program instead of the data table. In this case, both the transmitting side and the receiving side will calculate the present code from the previous code using random numbers.

In the above embodiment, the custom code 5 is used.
, Check code 6, function data 7,
Although the parity data 8 is sent, the check code may not be sent as long as the parity data is subjected to the exclusive OR of the custom code 5, the check code 6, and the function data 7.

This is because the check code 6 is obtained from the parity data 8, the custom code 5 and the function data 7 by calculation. As described above, even in the case where the check code is not transmitted, it is assumed that the check code is changed every time the command is transmitted according to the rule of the predetermined order as described above. The method is not limited to the exclusive OR, and any method can be used as long as it can be calculated backward. This change will be borne by the transmitted parity data.

Even if the same check data changes, if the custom code or function data is different, the parity data itself will be different, but it is calculated from the custom code, function data, and parity data. The change in the check data obtained in step 6 is the same even if the custom code or function code changes.

As described above, in the embodiment of the present invention, since the check code sequentially changes for each command repeatedly transmitted according to a predetermined rule, it is extremely unlikely that the same other signal is received, and the receiving side has a very small possibility. There is an advantage that the possibility of malfunctions is extremely reduced. Further, even if a part of the command is missed due to an obstacle or the like, normal control may be possible.

For example, as shown in FIG. 4, even if the check code 0D and FE of the repeatedly transmitted command are omitted,
If the subsequent EC (EC is a check code sent in the next transmission of FE) is normally received, if the missing period (for example, 200 ms) and the code that can be received for the first time (EC in this case) are known. , It could not be received for some reason due to the lack of time, but the sender either continued to send (the key was pressed continuously) or was interrupted once and then sent again (in this case, the code that comes after 200 ms is 0D It should be possible to judge.

This is a key for controlling only one operation at ON edge or OFF edge (for example, power ON / OFF, T
This is effective in the case of a remote control signal based on the operation of V / VTR switching). That is, when the power ON command is repeatedly sent many times, it can be determined that this is a repeatedly sent command (that is, the power ON command) even if the signal disappears in the middle.
This is because the power is not turned off. On the other hand, if the command is sent after being interrupted once, this is the power supply OF.
Judge as F command and turn off the power.

In general, when the power ON / OFF command is pressed by pressing the key once, the command works as the opposite command even though the data is the same. For example, if it is ON when first pressed, it works to turn OFF when next pressed. On the other hand, when the key is kept pressed, the same command (only ON or only OFF) is sent.

[0029]

As described above, according to the present invention, the check code sequentially changes according to a predetermined rule for each command repeatedly transmitted, so that it is highly possible that the same other signal is received. Therefore, the possibility of malfunctioning on the receiving side is eliminated.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a remote control transmitter embodying the present invention.

FIG. 2 is a circuit diagram showing a configuration of a remote control receiving circuit embodying the present invention.

FIG. 3 is a diagram showing a transmission command.

FIG. 4 is a diagram for explaining how commands are repeatedly transmitted.

FIG. 5 is a flowchart of command generation.

FIG. 6 is a diagram showing a data table for check codes.

[Explanation of symbols]

 5 Custom code 6 Check code 7 Function data 8 Parity data

Claims (2)

[Claims] 1. A check data is included in a command that is repeatedly transmitted a plurality of times, and the check data changes every time the command is sent in an order in accordance with a rule previously determined between sending and receiving. Command communication method. 2. A command that is repeatedly transmitted a plurality of times includes a data string and a parity data string, and the parity data string is a check data that changes every time the command is repeated in a predetermined order between transmission and reception, and the data. The command communication system is characterized in that the check data is not transmitted, and the reception side judges whether the command is true or false from the received parity data string.