JPH047151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication control method in an image data communication system in which at least three stations are connected to a transmission path and image data is transmitted between the stations via the transmission path.

Conventionally, in this type of image data communication system, the central processing unit and terminal that transmit image data are
It was not possible to determine how the sent image data would be processed on a terminal other than the one designated as the destination.

For example, in the case of an image data communication system using a connection method called loop connection as shown in Fig. 1, in Fig. 1, A to D are stations, and OF is for transmitting information between stations A to D. With the optical fiber line, stations A to B are connected in a loop with the optical fiber OF as described above.

Each station A to D has a reader R that scans the original image using a photoelectric conversion means using a photodiode array or a charge-coupled device (CCD) and outputs image data as a digital signal, and records the input image data and signal data. A working printer P such as a laser beam printer or a thermal printer is connected, and the stations A to D each have an electrical/optical converter (E/O converter) that converts an electrical signal into an optical signal and outputs it to an optical fiber OF. It has a built-in optical/electrical converter (O/E converter) that converts the optical signal input from the optical fiber OF into an electrical signal, and a control unit that controls the operation of the reader R and printer P, and the communication control with each station. .

In the image data communication system configured as described above, communication between each station was performed in the following manner. That is, the source first transmits the command packet shown in FIG. 2 to the optical fiber network. The command packet is a data string of ``0'' and ``1'' and consists of 32 serial signal data.
It has a bit configuration. Inside, each division has a meaning. That is, the 1st to 4th bits contain the address of the station to which the image data is to be sent, the 5th to 8th bits contain the address of the source of the image data, the 9th to 15th bits contain the number of originals to be sent, and the 16th bit contains the number of originals to be sent. is the size of the original image to be sent,
The 17th bit is a reception preparation command, the 18th bit is a transmission start command, the 19th bit is a reception completion indication, and the 20th bit is a reception completion command.
The 27th to 27th bits are blank, the 28th to 31st bits are a response to the above-mentioned command, and the 32nd bit indicates the meaning of the system operation indication by the ``0'' and ``1'' set in that bit.

Each station has a unique address and indicates in this packet the source and destination address numbers. As an example, a case where an image is transmitted from station A to station C will be described.

The source address is binary data indicating A,
The destination address is binary data indicating C. When station A transmits this packet, it is sent to station B in the designated transmission direction of the optical fiber loop (in this example, the direction indicated by the arrow in FIG. 1).

At station B, the control section receives the incoming command packet and evaluates the destination address field. In this case, at station B, the destination address in the packet does not match its own address, so station B
sends the received packet as is to the next station C.

Station C also evaluates whether the destination address of the command packet sent by the control unit matches its own address.
At station C, since it matches the destination address in the packet, preparations are made to transmit the image data sent through the optical fiber line OF to the input signal line of printer P, and then the 16th address of the command packet is transmitted. The bit-th reception preparation completion indication is set to "1" and sent to the next station D. By repeating this, the command packet sent by station A finally returns to station A, and by evaluating this command packet again at station A, it is sent to the station specified as the destination (in this case, station C). ) can be determined to be ready for reception. Then, the image data read by reader R of station A is sent out onto the optical fiber line OF, transmitted to station C via station B, becomes an input signal to printer P, and is reproduced in printer P. be done.

In the image data communication system using the communication method described above, each station only checks the destination address of the command packet, and checks the connection status with the printer P of stations other than the station designated as the destination. Since there is no active control to prohibit signal input to the printer P of stations that do not require transmission, there is no possibility that transmitted data will be transmitted to stations other than those designated as the source and destination. There was a possibility of leakage.

The present invention has been made to eliminate the drawbacks of the conventional examples described above, and more specifically, to provide an image data communication system in which transmitted data is not leaked to any destination other than the desired destination.
In a communication control method in an image data communication system in which two stations are connected to a transmission path and image data is transmitted between the stations via the transmission path, the image data source station transmits the image data. Then, a command specifying a destination station for the image data is sent to the transmission line, and the station specified as the destination by the command closes a switch for taking in image data from the transmission line, while , a station that is not designated as a destination by the command opens the switch, and all stations check the state of the switch of that station and determine whether the switch is open or closed. Based on the state data, the source station determines that the switch of the station designated as the transmission destination is in the closed state and that of the station not designated as the transmission destination. When it is determined that the switch is in the open state, the image data is sent to the transmission path, and on the other hand, if the switch of the station designated as the transmission destination is not in the closed state or the station designated as the transmission destination is The present invention provides a communication control method in which the image data is not sent to the transmission path when it is determined that the switch of the station that is not in use is not in the open state.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 shows an overall configuration diagram of the station in FIG. 1 according to an embodiment of the present invention. 31 is an O/E converter that converts optical signal data input from the optical fiber line OF1 into an electrical signal. 32 is an E/O converter which converts the electrical signal of the command signal and image data signal into an optical signal and outputs it to the optical fiber OF2. 3
3 is a receive command buffer for command packets.
It receives 32-bit serial data and is composed of, for example, a serial shift register. Reference numeral 34 denotes a transmission command buffer, which is a buffer for evaluating the received command packet and transmitting it to the outside again through the optical fiber line OF2. 35,
36 and 37 are changeover switches, and the changeover switch 35 is a switch that is closed when communicating between stations, and when that station is not a receiving station, input image data is passed and sent to the next station. .

The changeover switch 36 changes over the output signal of the reader R. The changeover switch 37 is for printer R.
This switch controls the image data signal to the station and is closed when guiding the image data input to the station to the printer P, and sets the data input path to the printer R. The connection status of this switch 36 is expressed by the confirmation signal line L. If it is "0", the optical fiber line OF1 and the printer P are not connected, and the image data is not output from the printer P. If it is "1", the connection state is established and the image data is output.

Note that the printer P and reader R are the same as those described in FIG. The main controller 38 controls the switches 35, 36, 37, received command analysis, and the transmission command buffer 34, and is constituted by a well-known microprocessor. Note that a confirmation signal line L is also input, and the state of the switch 37 is determined based on that signal. Further, 39 is a key and display from which the user inputs operation commands and displays the operating status of the device to the user.

FIG. 4 is a diagram showing the contents of the command information packet used in the present invention. The difference from FIG. 2 is that the 20th and
The 21st bit is provided with a division indicating the status of the confirmation signal from switch 37.

FIG. 5 shows the main controller 38 according to the present invention.
This control program is preset in the ROM of the microcomputer.

The present invention having the above configuration will be explained using an example in which image data is transmitted from station A to station C.

At station A, which is the source, a command packet in which the address of station A is displayed in the source address field and the address of station C is further displayed in the destination address field is set in the transmission command buffer 34 by the main controller 38. Ru. Each piece of information is entered through the key and display 39 section. and E/O converter 32
It is then sent to optical fiber line OF2.
This command packet is sent to Station B's O/E.
The command is input to the reception command buffer 33 through the conversion section 31.

The main controller 38
Evaluate the destination address of the command packet stored in the command packet. (Step S1) and confirm that station B is not the destination (step S1).
S2). Therefore, the main controller 38 closes the changeover switch 35, and thereafter switches the image data coming from the outside to be guided directly to the outside (step S8). At the same time, the changeover switch 37
is closed, and image data that will be input thereafter is not input to the printer P (step S9). Checking whether the changeover switch 37 is opened or not using the confirmation signal line (step S10),
If the output is "0", "0" is added to the value of the switch 37 signal in the input command packet (step S6). In the sending command buffer 34,
A command packet containing this added switch 37 signal and command information as received is set and sent to station C (step
S7).

On the other hand, when a command packet enters the receiving buffer 33 of station C, it is evaluated in the same way as described above (step S1), and station C determines that the destination address and its own address match (step S1).
S2). Therefore, the main controller 38 opens the changeover switch 35 (step S3) and switches the image data coming from the outside to the inside. At the same time, the changeover switch 37 is closed (step S4), and the image data is switched to be led to the printer P. It is checked by the confirmation signal line whether this changeover switch is closed (step S5), and if it is closed as set, "0" is added to the "switch 37 signal" in the command information packet (step S6). . This added switch 3 is added to the send command buffer.
7 signal and the command information indicating that reception is ready are set and sent to the next station P (step
S7). As a result of this repetition, the command packet finally sent out by station A returns to the original state and enters the received command buffer 33. The main controller 38 evaluates the "switch 37 signal" of this command packet that has returned, and if it is "0", it means that printers P other than the intended destination have been cut off from the optical fiber line by the changeover switch 37. Check and turn on the changeover switch 36.
The device reads the image of the document, sends the image data to the optical fiber line, and transmits the image data only to the intended destination.

In addition, if the changeover switch 37 is not closed for some reason at the station designated as the transmission destination, the main controller 38 of that station
outputs the value obtained by adding "1" to the switch 37 signal of the input command packet (step S11) as a new command packet. Furthermore, even if the changeover switch 37 is not opened for some reason at a station other than the station designated as the transmission destination, the main controller 38 of that station will add "1" to the switch 37 signal of the input command packet ( Step S11) is output as a new command packet.

If the switch 37 signal of the 20th and 21st bits of the command packet returned to the destination of the image data is not "0", that is, the switch 37 performs the predetermined opening/closing operation at the receiving station as described above. If this is not done, the sending station determines that it is unable to send image data to the desired station or that a station other than the desired station is able to take in image data, and stops sending the subsequent image data, or A display is displayed to inform the user that the state is inappropriate for transmission.

It is possible to know whether some receiving stations are inappropriate for transmitting image data by the value of the switch 37 signal of the command packet returned to the transmitting station.

As mentioned above, if an input path is set that allows image data to be received at a destination other than the intended destination, the switch 37 signal in the command packet will no longer be "0" and the source will return. This status can be known from the command packet.

Therefore, it can be confirmed whether or not confidentiality is maintained in the image communication system, and unnecessary information can be transmitted without leaking to a third party.

Furthermore, it is also possible to determine at the same time whether the desired destination is not in a receivable state.

As mentioned above, when transmitting image data,
The status of the input paths of all terminals can be determined on the sending side, and if it is inappropriate to send image data, it can stop sending the image data, thereby preventing the leakage of image data to unnecessary terminals. It is.

It goes without saying that the present invention is not limited to the above embodiments. For example, it can be applied to an image data system using a connection method called star connection. Further, the number of terminals is not limited to four, and the present invention can be similarly applied to other numbers. In that case, it goes without saying that the number of bits for setting the switch 37 signal will be increased according to the number of terminals.

As explained above, according to the present invention, a command for specifying a destination station is sent from a source station prior to sending image data, and a switch for capturing image data is activated at a station designated as a destination. , and any stations that are not designated as destinations open their switches, and all stations check the status of their switches, indicating whether they are open or closed. After transmitting the data, the source station determines, based on the state data, that the switch of the station designated as the transmission destination is in the closed state, and that the switch of the station not designated as the transmission destination is in the open state. Sometimes the image data is sent, but when it is determined that the switch of the station designated as the transmission destination is not in the closed state or that the switch of the station not designated as the transmission destination is not in the open state, the image data is not transmitted. .

This allows the source station to send image data and specify it as the destination when only the station specified as the destination by the command that specifies the destination station is in a state where it can capture image data. It becomes possible to reliably transmit image data to a station designated as a transmission destination without leaking the image data to a station that has not been used.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of an image data communication system according to the present invention, FIG. 2 is a diagram showing a command packet in a conventional system, and FIG. 3 is a diagram showing the configuration of an embodiment of a station according to the present invention. 4 is a diagram showing a command packet according to the present invention, and FIG. 5 is a flowchart diagram showing a control operation according to the present invention. A to D are stations,
R is a reader, P is a printer, 31 is an O/E converter, 32 is an E/O converter, 35 to 37 are changeover switches, and 38 is a main controller.

Claims (1)

[Claims] 1. A communication control method in an image data communication system in which at least three stations are connected to a transmission path and image data is transmitted between the stations via the transmission path, comprising: a source station of the image data; sends a command specifying a destination station of the image data to the transmission path prior to sending the image data, and the station designated as the destination by the command receives the image data from the transmission path. On the other hand, stations that are not specified as transmission destinations by the command open the switches, and all stations check the status of the switch of that station and open the switch. state data indicating whether the switch is in the closed state or closed state is sent to the transmission path, and the source station determines, based on the state data, that the switch of the station designated as the transmission destination is in the closed state. When it is determined that the switch of the station not designated as the transmission destination is in the open state, the image data is sent to the transmission path, while the switch of the station designated as the transmission destination is in the closed state. The communication control method is characterized in that the image data is not transmitted to the transmission path when it is determined that there is no station designated as the transmission destination or that the switch of the station that is not designated as the transmission destination is not in an open state.