JPH05292146A - Discrimination method for communication protocol - Google Patents

Abstract

PURPOSE:To attain the communication even when an edit equipment of a different protocol is connected to a special image processor by devising the method such that the detection of a breake signal discriminates a notice protocol of the edit equipment connecting to the special image processor automatically. CONSTITUTION:The communication tries at first by a protocol B in a special image processor 1. Whether or not a breake signal is detected is discriminated. When an edit equipment connecting to the processor is an edit equipment 2B using the protocol B, the edit equipment 2B and the processor 1 are communicated according to the protocol B. When the edit equipment connecting to the processor is an edit equipment 2A using a protocol A, an error takes place. Thus, a breake signal is sent to a controller 5 of the equipment 1 from the edit equipment 2. When the breake signal is detected, it is discriminated that the connected edit equipment is the edit equipment 2A using the protocol A. In this case, the communication is continued by the protocol A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication protocol discriminating method for discriminating which protocol is supported by a device to which a device operating under a different protocol is connected.

[0002]

2. Description of the Related Art In some cases, a system is constructed in which a plurality of electronic devices are connected to each other, communication is performed between them according to a predetermined protocol, and data and commands are exchanged between the electronic devices. For example, when editing a video screen,
A system capable of performing special image processing such as wipe, fader, and solarization on a desired screen is required. In order to construct such a special image processing system, a special image processing device and an editing machine are connected, and data and commands are exchanged between the special screen processing device and the editing machine. This makes it possible to easily perform an operation such as designating a desired screen and performing special image processing.

As described above, in order to exchange data and commands between each device, it is necessary to define a communication protocol. For example, two different protocols are mainly used as a protocol for constructing a system that performs special image processing. The difference between the two protocols is simply in the handling of communication errors. In one protocol, when a communication error occurs, the line is initialized and then communication is restarted. The other protocol does not handle communication errors.

[0004]

As described above, there are mainly two communication protocols in the system for performing the special image processing. However, conventionally, for example, it is not possible to determine which protocol is used by the editing machine connected to the special image processing apparatus. Therefore, the user confirms which protocol corresponds to the protocol of the editing machine to which the user is connected, and the user manually sets the protocol. Such manual protocol settings take time and effort for the user, and erroneous protocol settings are likely to occur.

Therefore, an object of the present invention is to provide a communication protocol discrimination method capable of automatically discriminating which protocol a connected device corresponds to.

[0006]

SUMMARY OF THE INVENTION The present invention is a communication protocol for determining a communication protocol of an electronic device connected to an electronic device capable of connecting electronic devices that communicate on two or more different communication protocols. At least one of the communication protocols is adapted to generate a special signal in order to restart the communication after initializing the communication line when a communication error occurs. It is a method of determining a communication protocol, which determines which communication protocol the connected device corresponds to, depending on whether or not such a signal is detected.

[0007]

By detecting the break signal, the communication protocol of the editing machine connected to the special image processing device can be automatically determined. Therefore, even if an editing machine having a different protocol is connected, the user can communicate with the special image processing apparatus without changing the protocol.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show an example of a special image processing system to which the present invention can be applied. In FIGS. 1 and 2, 1 is a special screen processing device, and 2A or 2B is an editing machine. Special image processing device 1 and editing machine 2A
Alternatively, the special screen processing device 1 and the editing device 2A or 2B are connected to each other via the transmission line 3 to perform data communication.

There are two types of data communication protocols. In one protocol, when a communication error occurs, the line is initialized and then communication is restarted. Hereinafter, such a protocol is referred to as protocol A. The other protocol does not handle communication errors. Hereinafter, such a protocol is referred to as protocol B. FIG. 1 shows an example in which an editor 2A corresponding to protocol A is connected. Figure 2
It shows an example in the case where the editing machine 2B corresponding to the protocol B is connected.

The special image processing procedure 1 is a video signal processing circuit 4 for performing processing such as wiping, fader and solarization on an input video signal, and a controller 5.
And have. The controller 5 controls the operation of the video signal processing circuit 4.

The editing machine 2A or 2B is a controller 6A.
Or 6B. When the operation panel 7A or 7B of the controller 56 or 6B is operated, the controller 6A
Alternatively, a command or data corresponding to this is generated from 6B. This command and data are sent via the transmission line 3.
It is transmitted to the controller 5 of the special image processing apparatus 1. As a result, the operation panel 7A or 7B of the editing machine 2A or 2B
With this operation, it is possible to specify a desired position on the screen and perform processing such as wiping, fader, and solarization on the input video signal.

As described above, the special image processing apparatus 1 includes the editing machine 2A (FIG. 1) which communicates with the protocol A,
There is a possibility that the editing machine 2B (FIG. 2) communicating with the protocol B will be connected. As shown in FIG. 1, the controller 6A of the editing machine 2A that communicates by the protocol A is provided with the communication module 10A of the protocol A. As shown in FIG. 2, the editing machine 2B that communicates by the protocol B is provided with a protocol B communication module 10B.

The controller 5 of the special image processing apparatus 1 is
In order to support the protocol A communication and the protocol B communication, a communication module 8A for performing the protocol A communication and a communication module 8B for performing the protocol B communication are provided. The protocol determination module 9 determines which protocol the connected editing machine 2A or 2B is. Then, the communication module 8A or 8B is selected according to the determined protocol.

Here, each communication protocol will be described. As described above, when the communication error occurs, the protocol A initializes the line and then restarts the communication. In this communication protocol, a command is sent from the editing machine 2A to the special image processing apparatus 1 and an answer is returned from the special image processing apparatus 1 to the editing machine 2A to perform communication. The message format of this protocol A is as follows.

The normal message format is (+ EFF + CMD + Par
a Blocks).

BC: Byte count (total number of bytes less than EFF. 03 or more, 7F or less)

EFF: Effect address

CMD: Command code

Para Blocks: A group of parameters attached to the command code.

For example, 03,01,10,01 is

03 = BC (3 bytes below EFF)

01 = EFF (channel 1)

10 = CMD (push button)

01 = Para Blocks (parameter of command code 10).

The control code is a 1-byte control code,

84 ACK acknowledgment

85 NAK Negative response

86 BUSY busy

It becomes

In the protocol A, there is a break as a special command in addition to this. Since this break signal is detected by hardware, it can always be transmitted / received regardless of whether the control code of the electronic message is transmitted. This break signal is used to initialize the communication line.

The communication line is initialized by the editor 2A sending a break signal to the special image processing apparatus 1. The conditions for initializing the communication line are when power-on / reset, when a communication error is detected, and when NAK is received.

On the other hand, the protocol B does not initialize the communication line, and only transmits a telegram according to the protocol B when communication is required. The electronic format of protocol B is as follows.

STX + BC + UA1 + UA2 + BT + CMD / MSG + CS

STX: Start of text code
Fixed at 02H

BC: Byte count Total number of bytes from UA1 to CMD / MSG

UA1: Fixed at unit address 1 31H

UA2: Unit address 2

BT: Block type of command
Fixed at 01H

CMD / MSG: Command code and message block

CS: Checksum

For example, (02,05,31,01,01,20,22,84)
Is

02 = Start of Text Code

05 = Byte count The total number of bytes from UA1 to CMD / MSG is 5 bytes.

31 = unit address 1

01 = Unit address 2

01 = BT

20 = command code

22 = message block

84 = Checksum

It becomes

The determination processing of such two communication protocols will be described. FIG. 3 is a flowchart showing a protocol determination process for determining which protocol the connected editing machine belongs to by the controller 5 of the special image processing apparatus 1.

As shown in FIG. 3, in the special image processing apparatus 1, at the time of power-on / reset, communication is first attempted by the protocol B (step 21).

Then, it is judged whether or not the break signal is detected (step 22).

Here, if the connected editing machine is the editing machine 2B of the protocol B, the protocol of the special image processing apparatus 1 and the protocol of the editing machine 2B are set to the same protocol. , Editing machine 2B
And the special image processing apparatus 1 communicate with each other.

If the connected editing machine is the editing machine 2A having the protocol A, an error occurs because the protocol set in the special image processing apparatus 1 is different from the protocol of the editing machine 2A. Therefore, the connected editing machine 2
The controller 6A of A sends a break signal to the controller 5 of the special image processing apparatus 1 in order to initialize the communication line. Therefore, the break signal is detected.

If a break signal is detected in step 22, it can be judged that the connected editing machine is the editing machine 2A of protocol A. In that case, the line is initialized (step 23) and communication is performed by the protocol A (step 24).

Then, it is judged whether a communication error occurs (step 25). If no error occurs, communication is continued with protocol A.

Here, the connected editor is the protocol B.
If it is changed to the editing machine 2B, a communication error occurs. If a communication error occurs, return to step 21,
Set to protocol B.

Here, when the editing machine is further changed to the editing machine 2A of protocol A, a break signal is generated from the editing machine 2A. If a break signal is detected in step 2A, the line is initialized (step 23) and protocol 2
Communication is performed at 4.

The above process is shown in a state transition diagram in FIG. As shown in FIG. 4, first, the protocol A is set in the power-on / reset state. If the connected editing machine is protocol B, a break signal is detected. When this break signal is detected, the state is changed to Protocol B. Here, when the connected editing machine becomes protocol A, a communication error is detected. Upon detecting a communication error, the state is changed from the protocol B to the protocol A.

[0061]

According to the present invention, by detecting the break signal, the communication protocol of the editing machine connected to the special image processing apparatus can be automatically determined. Therefore, even if an editing machine having a different protocol is connected, the user can communicate with the special image processing apparatus without changing the protocol.

[Brief description of drawings]

FIG. 1 is a block diagram used to describe an embodiment of the present invention.

FIG. 2 is a block diagram used to describe an embodiment of the present invention.

FIG. 3 is a flowchart used to describe an embodiment of the present invention.

FIG. 4 is a state transition diagram used for explaining one embodiment of the present invention.

[Explanation of symbols]

 1 Special image processing device 2A, 2B editing machine 5, 6A, 6B controller 9 Protocol determination module

Claims (1)

[Claims] 1. A communication protocol determination method for determining a communication protocol of an electronic device connected by an electronic device capable of connecting with an electronic device capable of communicating on two or more different communication protocols, comprising: At least one of the protocols is designed to generate a special signal in order to initialize the communication line and restart communication when a communication error occurs. Is the above special signal detected? A communication protocol determination method characterized by determining which communication protocol a connected device corresponds to, depending on how.