JPH0965178A - Signal transmission device and method thereof - Google Patents

Abstract

It is possible to transmit a signal between two devices connected via a communication line and a response signal to the signal. An editing device 1 has a control function for generating and transmitting a command to a VTR device 3, as well as a time-over function and a retry function. Terminal device 5a
Sends a command from the editing device 1 to the VT via the public network 4.
It transmits to the R device 3, and transmits the response signal from the VTR device 3 to the VTR device 3. The terminal device 5a uses the NAK when the editing device 1 is about to expire.
By transmitting some kind of response signal such as, the occurrence of time over in the editing device 1 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal transmission apparatus and method for transmitting a signal and a response signal to the signal via a communication line having a transmission delay between two apparatuses.

[0002]

In a television broadcasting station or the like, an editing device and a video tape recorder (VTR) are used.
Device) and the VTR device is controlled from the editing device to edit the audio / video for the program. FIG. 7 is a diagram showing a general connection method between the editing device 1 and the VTR device 3 to be controlled. As shown in FIG. 7, generally, the editing device 1 and the VTR device 3 are directly connected via a cable 2 for RS422 or the like.

FIG. 8 shows an editing apparatus 1 and a VTR shown in FIG.
6 is a signal sequence diagram showing a control signal (command) and a response signal transmitted to and from the device 3. FIG. As shown in FIG. 8, when a command is directly transmitted from the editing device 1 to the VTR device 3 via the cable 2 and the response signal from the VTR device 3 is received by the editing device 1, the editing device 1 uses the cable 2. The transmission delay time hardly matters. Therefore, due to the transmission delay time, the command set in the editing device 1 is transmitted to the VTR device 3 and then the VTR device 3 is transmitted.
Timeout does not occur due to the elapse of the time limit until the response from is obtained. The time limit set in the editing device 1 is usually 9 ms. This value of 9 ms is VT
It has become the de facto standard as a time limit set for the editing device that controls the R device.

FIG. 9 is a diagram showing a connection method for connecting the editing apparatus 1 and the VTR apparatus 3 via the public network 4.
FIG. 10 is a signal sequence diagram showing commands and response signals transmitted between the editing device 1 and the VTR device 3 shown in FIG. The public network 4 shown in FIG. 9 is an ISDN communication line, an analog telephone line, or the like, and the editing device 1 and the VTR device 3 are connected to the public network 4 using the cable 2 and the terminal devices 64a and 64b, respectively. It is possible to transmit control signals and response signals between them.

However, when the control signal and the response signal are transmitted via the public network 4, these signals receive a transmission delay T _d from the public network 4. Therefore, as shown in FIG.
Even if the editing device 1 sends the command 1 to the VTR device 3,
The response signal 1 corresponding to the command 1 does not always reach the editing device 1 from the VTR device 3 within the time limit (9 ms) after the transmission, and the editing device 1 times out.
When a time-out occurs, depending on the editing device 1, the editing device 1 may determine that the control of the VTR device 3 is impossible, and abandon the control of the VTR device 3.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a VTR device or the like connected to a control device such as an audio / video editing device via a communication line having a transmission delay time. Between the control target device and the control target device, and a control signal from the control device to the control target device, and
An object of the present invention is to provide a signal transmission device and a method thereof capable of transmitting a response signal to a control device from a device to be controlled.

Further, according to the present invention, when a time limit is set for the time from the transmission of the control signal to the control device until the reception of the response signal, and the control device times out,
Provided are a signal transmission device and a method thereof, which do not cause a timeout and a process relating to the timeout caused by a transmission delay of a communication line connecting a control device and a device to be controlled even when performing a process relating to the timeout such as control abandonment. The purpose is to do. Further, the present invention is applicable to a wide range of control devices, and an object of the present invention is to provide a signal transmission device capable of transmitting a control signal and a response signal via a communication line having a transmission delay, and a device therefor. .

[0008]

In order to achieve the above object, a signal transmission device according to the present invention comprises a first device having recording / reproducing means for recording / reproducing audio / video data,
A second device that performs transmission control immediately between a second device that processes audio / video data recorded in the first device and a communication system that has a predetermined transmission delay time. A signal transmission device comprising: a first transmission control device; and a second transmission control device that instantaneously performs transmission control between the second device and the communication system, the second device comprising: A predetermined time limit is set between transmitting the control signal to the first device and receiving the response signal transmitted from the first device after transmitting the control signal. The first device transmits a predetermined response signal to the first device in response to the control signal transmitted from the second device, and the first transmission control device is configured to transmit the second response signal to the second device. Transmitted from the second device via the transmission control device and the communication system. First control signal transmitting means for transmitting the control signal to the first device, and a response signal transmitted from the first device via the communication system and the second transmission control device. A first response signal transmitting means for transmitting to the second device, wherein the second transmission control device receives the control signal transmitted from the second device and receives the first transmission signal. When the response signal is not transmitted from the first device via the control device and the communication system within the time limit, the first device receives the control signal among the response signals. Signal returning means for transmitting to the second device a predetermined communication control signal indicating
Second control signal transmitting means for transmitting the control signal transmitted from the second device to the first device via the communication system and the first transmission control device; A device receives a response signal transmitted to the second device via the first transmission control device and the communication system in response to the control signal, and stores and stores the response signal, and the stored response. A further transmitting a response signal corresponding to the received control signal among the stored response signals to the second device when a control signal corresponding to the signal is further received from the second device; 2 response signal transmitting means.

Preferably, the signal returning means of the second transmission control device indicates that the first device rejects the control signal transmitted by the second device among the response signals. NAK is transmitted to the second device as the communication control signal, and the second device sends the same control signal when the NAK of the response signals is received within the time limit. Has a retry function.

Preferably, the signal returning means of the second transmission control device indicates that the first device has accepted the control signal transmitted by the second device among the response signals. ACK is transmitted to the second device as the communication control signal, and the second device further transmits the same control signal after transmitting the control signal and receiving ACK from the signal returning means, When the response signal transmitted from the first device via the first transmission control device and the communication system is received from the second response signal transmitting means of the second transmission control device, The AC received before
Process as the response signal corresponding to K.

A second transmission control device according to the present invention is a communication system having a predetermined transmission delay time, such as an ISDN line and an analog communication line, and a limit time from transmission of a control signal to timeout. A control device and a response signal are transmitted between the control device and a second device such as a VTR device or a hard disk device that records / reproduces audio / video data by connecting a first device such as a device.

In the first transmission control device of the signal transmission device according to the present invention, the first control signal transmission means is transmitted from the second device via the second transmission control device and the communication system. For example, let the first device perform fast-forward playback,
Alternatively, a control signal for transmitting a time stamp value or the like is transmitted to the first device. The first response signal transmitting means outputs the response signal output from the first device in response to the control signal transmitted from the first device to the communication system and the second device.
Is transmitted to the second device via the transmission control means.

In the second transmission control device, the signal returning means receives the control signal from the second device, for example, 9
Even if 90% (8.1 ms) of the ms time limit has elapsed
When there is no response from the device, and it is determined that the response signal is not transmitted from the first device even if the time limit has passed,
To the second device, a signal (display signal) indicating that a control signal such as ACK or NAK defined by the RS422 interface protocol is received is returned to the second device,
Preventing timeouts and timeout related actions from occurring in the second device.

The second control signal transmitting means transmits the control signal received from the second device to the first device via the communication line. Upon receiving the control signal, the first device generates a response signal according to the content of the control signal, and transmits the response signal via the communication line. As the response signal, for example, when the control signal causes the VTR device to fast-forward, the above-mentioned ACK, NAK, etc. are transmitted, and when the control signal requests transmission of the time stamp, the value of the time stamp. Will be sent.

The response signal receiving means receives the response signal sent from the first device and buffers it in accordance with the control signal received from the second device. The second response signal transmitting means receives the same control signal as the control signal received once from the control signal, and then receives the control signal once or more times, and the response signal is buffered corresponding to the control signal. In that case, the buffered response signal is transmitted to the second device. In this way, since the response signal transmitted from the first device is input to the second device in synchronization with the control signal of the second device, control between the second device and the first device is performed. The signal communication sequence is not broken.

Further, in the signal transmission method according to the present invention, the control signal immediately received from the side transmitting the control signal is transmitted to the side receiving the control signal via the communication system having the predetermined transmission delay time. A signal transmission method in which the receiving side transmits a response signal transmitted in response to the received control signal to the transmitting side, wherein the transmitting side transmits a control signal and then the receiving side. When a predetermined time limit is set until the response signal from the receiving side is received, the control signal from the transmitting side is received, and there is no response signal from the receiving side within the time limit. , Returns the predetermined response signal to the transmitting side.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a diagram showing a configuration of a data transmission system 10 according to the present invention in the first embodiment. As shown in FIG. 1, in a data transmission system 10, for example, an editing apparatus 1 of a certain television broadcasting station, which is connected to a terminal device 5a according to the present invention via a cable 2 for RS422, and a cable 2. A VTR device 3 of, for example, another television broadcasting station connected to the terminal device 5b through the public network 4.

The editing device 1 is a device used to edit audio / video signals for a program. The editing device 1
When the public network 4 is not used, for example, it is directly connected to the VTR device 3 as shown in FIG. 7, and a control signal (command) RS422 is sent to the VTR device 3 as shown in FIG. It transmits according to the interface protocol to control the VTR device 3, or receives a response signal returned from the VTR device 3 in response to a command.

Further, the editing apparatus 1 is provided with a time limit from when a command is sent to the VTR device 3 until a response signal is received from the VTR device 3,
When the response signal from the TR device 3 does not return even after the time limit has passed, the editing device 1 has timed out, and a process for timed-out such as control abandonment to the VTR device 3 is started.

Further, in the first embodiment, the editing device 1 receives the NAK (described later in the description of the terminal device 5a) as a response signal from the VTR device 3 (terminal device 5a), and then the same command is issued again 10 ms later. Has a so-called retry function. The time limit is 9 ms
Then, setting the retry interval to 10 ms is a practical standard for controlling the VTR device. The public network 4 transmits the command from the editing device 1 transmitted via the cable 2 and the terminal device 5a to the terminal device 5b, and also the response signal transmitted via the cable 2 and the terminal device 5b. Is transmitted to the terminal device 5a. It should be noted that the public network 4 transmits the signal transmitted between the VTR device 3 and the editing device 1 to a transmission delay T _d (for example, 2T _d ≧ 9 m).
s) is given.

FIG. 2 is a diagram showing the configuration of the terminal device 5a according to the present invention shown in FIG. As shown in FIG. 2, the terminal device 5a includes a network interface 50, a control circuit (CP
U) 52, an RS422 interface 54, and a memory circuit 56. Network interface 50
Interfaces the transmission and reception of signals between the public network 4 and the control circuit 52.

The control circuit 52 is composed of, for example, a one-chip microprocessor containing a ROM for storing a program, and the public network 4 described later with reference to FIGS. 3 and 4.
Executes communication control between and. The RS422 interface 54 serves as an interface for transmitting and receiving signals between the cable 2 and the control circuit 52. The memory circuit 56 stores data necessary for the processing of the control circuit 52. Note that the storage space of the memory circuit 56 is
Are used by being logically divided into areas corresponding to the commands transmitted by the editing device 1, and the response signals transmitted by the VTR device 3 in response to the commands are buffered in the respective areas corresponding to the commands.

The terminal device 5a connects the editing device 1 (cable 2) and the public network 4 by these components,
The command transmitted from the editing device 1 is transmitted to the VTR device 3 via the public network 4, and the response signal transmitted from the VTR device 3 via the public network 4 is V
Output to the TR device 3. In addition, the terminal device 5a
If the editing device 1 is about to run out of time, VT
Of the response signals to be returned from the R device 3 to the editing device 1, for example, a signal ACK indicating that the VTR device 3 has received the command from the editing device 1 and has accepted control,
Alternatively, NAK indicating that it was received but refused control.
Etc. to the editing device 1. In this way, the editing device 1 prevents the occurrence of time-out in the editing device 1 by transmitting any response signal from the terminal device 5a to the editing device 1.

The terminal device 5b has, for example, the same configuration as the terminal device 5a, and includes the VTR device 3 (cable 2) and the public network 4
And the command transmitted from the editing device 1 via the public network 4 to the VTR device 3 and the response signal transmitted from the VTR device 3 to the editing device 1 via the public network 4. To send.

The operation of the data transmission system 10 will be described below with reference to FIG. 3 is a block diagram of the data transmission system 10 according to the present invention shown in FIG.
5 is a signal sequence diagram showing commands and response signals transmitted to and from the TR device 3. FIG.

As illustrated in FIG. 3, the editing device 1 first transmits, for example, a command 1 requesting the VTR device 3 to transmit a time stamp to the terminal device 5a via the cable 2. The terminal device 5a is a VTR via the public network 4.
Command 1 is sent to device 3. The command 1 transmitted by the terminal device 5a is received by the VTR device 3 via the public network 4, the terminal device 5b, and the cable 2. Upon receiving the command 1, the VTR device 3 transmits the response signal 1 including the value of the time stamp to the editing device 1.

The terminal device 5a is connected to the VTR via the public network 4.
A command 1 is transmitted to the device 3 and, for example, a NAK is returned to the editing device 1 within 9 ms. After receiving the NAK from the terminal device 5a, the editing device 1 transmits the command 1 to the terminal device 5a again after 10 ms (retry (retry) 1). In the example of FIG. 3, when the retry 1 is performed, the VTR device 3 to the terminal device 5
Since the response signal 1 to the command 1 has not reached a, the terminal device 5a returns NAK to the editing device 1 again without transmitting the command 1 to the VTR device 3.

The editing apparatus 1 performs the retry 1 and further 1
When 0 ms elapses, the editing device 1 transmits the third command 1 to the VTR device 3 (retry 2). Since the response signal 1 has reached the terminal device 5a at the time when the editing device 1 performs the retry 2, the terminal device 5a displays the VTR.
The response signal 1 transmitted from the device 3 is transmitted to the editing device 1 via the cable 2. As described above, the editing device 1 controls the VTR device 3 through the communication line having a round trip transmission delay of 2T _d (≧ 9 ms) as a result of the two retries, and controls the VTR device 3 from the VTR device 3. You can get the value of the timestamp.

FIG. 4 is a diagram showing processing of a program executed by the control circuit 52 of the terminal devices 5a and 5b shown in FIG. 2 in order to realize the communication sequence shown in FIG. In addition, the program shown in FIG.
Consideration has been paid to standardize the processing in a and 5b.

As shown in FIG. 4, step 01 (S0
In 1), the control circuit 52 determines whether or not a command for the connected editing device 1 has been received directly via the cable 2. If the control circuit 52 has received a command from the editing device 1 via the cable 2, the process proceeds to S04, and if not, the process proceeds to S02. Note that the process of S01 is necessary when the control circuit 52 is used inside the terminal device 5a.

In step 02 (S02), the control circuit 52 determines whether or not a command has been received from the editing device 1 via the public network 4. If the control circuit 52 receives a command from the editing device 1 via the public network 4, the process proceeds to S0.
Proceeds to the process of 3 and if no command is received, S
The process proceeds to 01. In step 03 (S03),
The control circuit 52 transmits a command received from the editing device 1 via the public network 4 to the VTR device 3 via the cable 2. The processing in S02 and S03 is performed by the control circuit 5
2 is required when used inside the terminal device 5b.

At step 04 (S04), the control circuit 52 transmits the command received from the editing device 1 via the cable 2 to the VTR device 3 via the public network 4. In step 05 (S05), the control circuit 5
2 determines whether or not a response signal has been received from the VTR device 3 via the public network 4. When the control circuit 52 receives a response signal from the VTR device 3 via the public network 4, S0
When the process proceeds to the process of 6, and the response signal is not received, S
Proceed to 07.

In step 06 (S06), the control circuit 52 transmits the response signal received from the VTR device 3 via the public network 4 to the editing device 1 via the cable 2.
In step 07 (S07), the control circuit 52 determines whether or not about 9 ms has elapsed after receiving the command from the editing device 1 via the cable 2, that is, whether or not the editing device 1 is likely to time out. To do. Editing device 1
If a time-out is likely to occur, the process proceeds to S08, and if a time-out is not likely to occur, S06
Stay in the process.

At step 08 (S08), the control circuit 52 sends NAK to the editing apparatus 1 via the cable 2. In step 09 (S09), the control circuit 52
Determines whether a response signal has been received from the VTR device 3 via the public network 4. When the control circuit 52 receives the response signal, the process proceeds to S11, and when the response signal is not received, the process proceeds to S10.

In step 10 (S10), the control circuit 52 sets the response flag to the value 1 (true). Step 11
In (S11), the control circuit 52 sets the response flag to the value 0.
(False) In step 12 (S12), the control circuit 52 determines whether or not a command has been received from the editing device 1 via the cable 2. When the control circuit 52 receives the command, the process proceeds to S14, and when the command is not received, the process proceeds to S13.

In step 13 (S13), the control circuit 52 determines whether the response flag has a value of 1. If the value of the response flag is 1, the process proceeds to S12, where the value is 0.
If it is, the process proceeds to S14. Step 14 (S
In 14), the control circuit 52 determines whether the command received from the editing device 1 via the cable 2 last time is the same as the command received from the editing device 1 via the cable 2 this time. If the two commands are the same, the process proceeds to S15; otherwise, the process proceeds to S08.

In step 15 (S15), the control circuit 52 determines whether or not the value of the response flag is 1.
If the value of the response flag is 1, the process proceeds to S16, and if the value is 0, the process proceeds to S01. In step 16 (S16), the control circuit 52 transmits the response signal received from the VTR device 3 via the public network 4 to the cable 2
To the editing device 1 via. Note that S04 to S16
This process is required when the control circuit 52 is used inside the terminal device 5a.

The command between the editing device 1 and the VTR device 3 is not limited to the one for notifying the time stamp, and for example, the VTR device 3 is fast-forwarded, fast-rewound, reproduction is started, or It may be another command for controlling the reproduction to end. Further, not only the editing device 1 but also another control device can be connected to the terminal device 5a, and not only the VTR device 3 but also another control target can be connected to the terminal device 5b.

When the editing device 1 performs simple control such as controlling the VTR device 3 to fast-forward,
The VTR device 3 does not transmit a response signal corresponding to the control signal as a response signal, but simply transmits simple data such as ACK and NAK. Even in this case, the editing apparatus 1 can perform the VT without the time lapse due to the processing shown in FIG.
The R device 3 can be controlled.

Second Embodiment Below, a second embodiment of the present invention will be explained. The second embodiment is similar to the first embodiment in the data transmission system 1
0 (FIG. 1), the programs of the terminal devices 5a and 5b are changed so that the editing device 1 does not have the retry function and does not accept NAK.

The editing apparatus 1 according to the second embodiment is similar to the editing apparatus 1 according to the first embodiment in that the VTR device 3 is used.
When the response signal from the VTR device 3 does not return even after the time limit has expired, a time-over occurs and a process related to the time-over is started. However, the editing apparatus 1 according to the second embodiment
Unlike the editing device 1 according to the first embodiment, does not have a retry function, and even if it has a function of receiving both ACK and NAK, it can only receive ACK and It may have a function that cannot be received.

The terminal devices 5a and 5b are the first devices shown in FIG.
It has the same configuration as the terminal devices 5a and 5b in the embodiment, and performs the same operation. However, the programs stored in the internal ROM of the control circuit 52 of the terminal device 5b are different (FIG. 6). Based on the program stored in the internal ROM of the control circuit 52, the terminal device 5a transmits the command from the editing device 1 to the VTR device 3 as well as the terminal device 5a in the first embodiment. VT
The response signal from the R device 3 is output to the VTR device 3.

Further, the terminal device 5a selects, for example, V from the response signals to be returned from the VTR device 3 to the editing device 1 when the editing device 1 is about to time out.
The TR device 3 receives a command from the editing device 1 and transmits a signal ACK indicating that the control has been accepted to the editing device 1 to prevent the editing device 1 from timing out.

The terminal device 5b performs the same operation as the terminal device 5b in the first embodiment. The components of the data transmission system 10 according to the second embodiment other than the editing device 1 and the terminal devices 5a and 5b, the cable 2, and the VTR.
The device 3 and the public network 4 are the same as the cable 2, the VTR device 3 and the public network 4 in the first embodiment, respectively.

The operation of the data transmission system 10 will be described below with reference to FIG. FIG. 5 shows an editing device 1 and a VT in the data transmission system 10 according to the second embodiment.
5 is a signal sequence diagram showing commands and response signals transmitted to and from the R device 3. FIG.

As illustrated in FIG. 5, the editing apparatus 1 first transmits, for example, the command 1 requesting the VTR apparatus 3 to transmit the time stamp to the terminal apparatus 5a. The terminal device 5a transmits ACK to the editing device 1, and within the time limit (9 ms), the VTR device 3 via the public network 4.
Command 1 is transmitted to The command 1 transmitted by the terminal device 5a is received by the VTR device 3, and the VTR device 3 transmits the response signal 1 including the value of the time stamp to the editing device 1 (terminal device 5a). Response signal 1
When it reaches the terminal device 5a, is buffered in the storage area for the command 1 of the memory circuit 56 (FIG. 2) of the terminal device 5a.

Since the editing device 1 does not have the retry function, the command to be transmitted second is not necessarily the command 1, but the command 2 for controlling the VTR device 3 to perform the fast-forward control, for example, the terminal device 5a. Send to. The terminal device 5a transmits an ACK to the editing device 1 within the time limit and transmits a command 2 to the VTR device 3 as in the case of the command 1. The command 2 transmitted by the terminal device 5a is received by the VTR device 3, and the VT
The R device 3 transmits a response signal 2, for example, ACK, to the editing device 1 (terminal device 5a). The response signal 2 reaching the terminal device 5a is buffered in the storage area for the command 2 of the memory circuit 56.

Next, the editing device 1 sends a command 1'having the same content as the command 1 to the terminal device 5a. The terminal device 5a transmits the command 1 to the VTR device 3 and the response signal 1 buffered in the command 1 area of the memory circuit 56 to the editing device 1. On the other hand, when the control signal 1'is received by the VTR device 3 and the response signal 1'to the command 1'transmitted by the VTR device 3 reaches the terminal device 5a, the terminal device 5a buffers the response signal 1'and stores it in the memory. The storage area for the command 1 of the circuit 56 is updated.

As described above, in the data transmission system 10 shown in the second embodiment, even if the editing apparatus 1 cannot receive the NAK and does not have the retry function, the editing apparatus 1 does not have the retry function. It is possible to control the VTR device 3 from the editing device 1 via the public network 4 without generating a timeout.

FIG. 6 is a diagram showing processing of a program executed by the control circuit 52 of the terminal devices 5a and 5b shown in FIG. 2 in order to realize the communication sequence shown in FIG. It should be noted that the program shown in FIG. 6 is similar to the program processing of the terminal devices 5a and 5b shown in FIG. 3 in the first embodiment in consideration of sharing the processing in the terminal devices 5a and 5b. It is being appreciated.

As shown in FIG. 6, step 20 (S2
In 0), the control circuit 52 determines whether or not a command has been received via the cable 2 from the editing device 1 connected directly via the cable 2. When the control circuit 52 receives a command from the editing device 1 via the cable 2, the process proceeds to S24, and when the command is not received, the process proceeds to S21. Step 21 (S2
In 1), the control circuit 52 sends the VT
It is determined whether or not a response signal is received from the R device 3. When the control circuit 52 receives the response signal from the public network 4, the process proceeds to S25, and when the response signal is not received, the process proceeds to S22. The processes in S20 and S21 are required when the control circuit 52 is used inside the terminal device 5a.

In step 22 (S22), the control circuit 52 determines whether or not a command has been received from the editing device 1 via the public network 4. If the control circuit 52 receives a command from the editing device 1 via the public network 4, the process proceeds to S26.
If the command is not received, S2
Proceed to step 3. In step 23 (S23), the control circuit 52 determines whether or not a response signal has been received from the VTR device 3 via the cable 2. When the control circuit 52 receives the response signal from the VTR device 3 via the cable 2, the process proceeds to S27, and when the command is not received, the process proceeds to S23. The processing of S22 and S23 is necessary when the control circuit 52 is used inside the terminal device 5b.

In step 24 (S24), the control circuit 52 transmits the command received from the editing device 1 via the cable 2 to the VTR device 3 via the public network 4, and proceeds to the processing of S20. In step 25 (S25), the control circuit 52 buffers the response received from the VTR device 3 via the public network 4 in a predetermined storage area of the memory circuit 56, and proceeds to the process of S20. Note that S24,
The process of S25 is necessary when the control circuit 52 is used inside the terminal device 5a.

In step 26 (S26), the control circuit 52 transmits the command received from the editing device 1 via the public network 4 to the VTR device 3 via the cable 2, and proceeds to the processing of S20. In step 27 (S27), the control circuit 52 sends the VTR device 3
The response signal received from is transmitted to the editing device 1 via the public network 4, and the process proceeds to S20. Incidentally, S26, S
The processing of 27 is necessary when the control circuit 52 is used inside the terminal device 5a.

In step 24 (S24), the control circuit 52 transmits the command received from the editing device 1 via the cable 2 to the VTR device 3 via the public network 4. In step 28 (S28), the control circuit 52
Determines whether the command received from the editing apparatus 1 via the cable 2 simply requests ACK or the like as a response signal. If the command meets this condition, the process proceeds to S31, and if the command does not meet the condition, S29.
Go to processing. (Please check the contents of the process of ******** S28 *****)

In step 29 (S29), the control circuit 52 determines whether or not the response signal corresponding to the received command is buffered in a predetermined storage area of the memory circuit 56. When the response signal corresponding to the command is buffered, the processing proceeds to S30,
If it is not buffered, the process proceeds to S31.

In step 30 (S30), the control circuit 52 transmits a response signal corresponding to the buffered command to the editing device 1 via the cable 2. In step 31 (S31), the control circuit 52
Transmits ACK to the editing device 1 via the cable 2. The processing of S28 to S31 is necessary when the control circuit 52 is used inside the terminal device 5a.

The data transmission system 10 according to the present invention shown in the second embodiment also prevents the occurrence of time-out in the editing apparatus 1 as in the data transmission system 10 shown in the first embodiment, and the public Editing device 1 via network 4
Can control the VTR device 3. Moreover, in the data transmission system 10 according to the present invention shown in the second embodiment, since the editing apparatus 1 is not required to have the retry function, the applicable range is wider. Also for the data transmission system 10 shown in the second embodiment, the first
Modifications similar to those of the data transmission system 10 shown in the embodiment can be made.

[0059]

As described above, according to the signal transmission apparatus and method of the present invention, a VTR connected to a control apparatus such as an audio / video editing apparatus via a communication line having a transmission delay time. A control signal from the control device to the device to be controlled and a response signal to the control device from the device to be controlled can be transmitted between the device and other devices to be controlled.

Further, according to the signal transmission device and the method thereof according to the present invention, the time limit from the transmission of the control signal to the control device until the reception of the response signal is set, and the control device times out. In this case, even if a process related to a timeout such as abandonment of control is performed, a timeout and a process related to the timeout caused by the transmission delay of the communication line connecting the control device and the device to be controlled do not occur. Further, the signal transmission device and the method thereof according to the present invention can be applied to a wide range of control devices,
It is possible to transmit the control signal and the response signal via the communication line having the transmission delay.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a data transmission system according to the present invention in a first embodiment.

FIG. 2 is a diagram showing a configuration of a terminal device according to the present invention shown in FIG.

3 is a signal sequence diagram showing commands and response signals transmitted between an editing device and a VTR device in the data transmission system according to the present invention shown in FIG.

4 is a diagram showing processing of a program executed by a control circuit of the terminal device shown in FIG. 2 in order to realize the communication sequence shown in FIG.

FIG. 5 is a signal sequence diagram showing commands and response signals transmitted between an editing device and a VTR device in the data transmission system according to the second embodiment.

6 is a diagram showing processing of a program executed by the control circuit of the terminal device shown in FIG. 2 in order to realize the communication sequence shown in FIG.

FIG. 7 is a diagram showing a general connection method between an editing device and a VTR device to be controlled.

8 is a signal sequence diagram showing commands and response signals transmitted between the editing device and the VTR device shown in FIG.

FIG. 9 is a diagram showing a connection method for connecting an editing device and a VTR device via a public network.

10 is a signal sequence diagram showing commands and response signals transmitted between the editing device and the VTR device shown in FIG.

[Explanation of symbols]

1 ... Editing device, 2 ... Cable, 3 ... VTR device, 4 ... Public network, 5a, 5b ... Terminal device, 50 ... Network interface, 52 ... Control circuit, 54 ... RS422 interface, 56 ... Memory circuit

Claims (4)

[Claims] 1. Recording / reproducing of audio / video data
A first device having a reproducing means; and a second device for processing audio / video data recorded in the first device,
A first transmission control device that instantaneously controls transmission between the first device and a communication system having a predetermined transmission delay time, and an instant between the second device and the communication system A signal transmission device having a second transmission control device that performs transmission control, wherein the second device transmits a predetermined control signal to the first device, and then transmits the control signal. A predetermined time limit is set until the response signal transmitted from the first device is received, and the first device responds to the control signal transmitted from the second device. A predetermined response signal is transmitted to the first device, the first transmission control device is configured to transmit the control signal transmitted from the second device via the second transmission control device and the communication system. A first control signal transmitting means for transmitting to the first device, The response signal transmitted from the first device is transmitted to the second device via the communication system and the second transmission control device.
And a first response signal transmitting means for transmitting to the device, the second transmission control device receives the control signal transmitted from the second device,
When the response signal is not transmitted from the first device via the first transmission control device and the communication system within the time limit, the first device controls the control signal among the response signals. A signal returning means for transmitting a predetermined communication control signal indicating that the signal has been received to the second device; and the control signal transmitted from the second device for the communication system and the first transmission. Second control signal transmitting means for transmitting to the first device via a control device; and the first device according to the control signal, via the first transmission control device and the communication system. Response signal receiving means for receiving and storing the response signal transmitted to the second device; and a control signal corresponding to the stored response signal for the second device.
Second response signal transmitting means for transmitting, to the second device, the response signal corresponding to the received control signal among the stored response signals when further received from the device. apparatus. 2. The signal returning means of the second transmission control device indicates that the first device rejects the control signal transmitted by the second device among the response signals.
K is transmitted to the second device as the communication control signal, and the second device sends the same control signal when the NAK of the response signals is received within the time limit. The signal transmission device according to claim 1, which has a retry function. 3. The signal return means of the second transmission control device indicates that the first device has accepted the control signal transmitted by the second device among the response signals.
CK is transmitted to the second device as the communication control signal, the second device transmits the control signal, and after receiving ACK from the signal returning means, further transmits the same control signal, When the response signal transmitted from the first device via the first transmission control device and the communication system is received from the second response signal transmitting means of the second transmission control device, The signal transmission device according to claim 1, wherein the signal transmission device processes as the response signal corresponding to the previously received ACK. 4. A control signal immediately received from a side transmitting a control signal is transmitted to a side receiving the control signal via a communication system having a predetermined transmission delay time, and the side receiving the signal receives the control signal. A signal transmission method for transmitting a response signal transmitted according to the control signal to the transmitting side, wherein the transmitting side receives the response signal from the receiving side after transmitting a control signal. Until a predetermined time limit is set, the control signal from the transmitting side is received, and there is no response signal from the receiving side within the time limit, the predetermined response signal is transmitted. Signal transmission method to return to the side to do.