JPH04235439A - Protocol conversion device - Google Patents

Abstract

PURPOSE:To prevent a telegraphic message from being destructed due to excessive, accumulation of the telegraphic messages even when a device provided with no host protocol layer and provided with mutually different protocols is connected. CONSTITUTION:A communication control parts 1(a) and 1(b) conduct the control of communication with an opposite equipment, transmit the received telegraphic message to a protocol conversion part 2, receive the telegraphic message for which the protocol conversion is performed from the protocol conversion part 2 and transmit it to the opposite equipment and when input regulation is applied to the received telegraphic message by the opposite equipment, store the received telegraphic message in transmission standby telegraphic message storage areas 4a and 4b, and read out the received telegraphic message and output it as the receiving telegraphic message when the input regulation is released. A state monitoring part 3 monitors the communication state of the protocol, judges whether or not the input regulation is to be conducted against the communication control parts 1(a) and 1(b), and instructs the input regulation to the communication control parts 1(a) and 1(b), respectively, when the input regulation is required.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protocol conversion device, and more particularly to a protocol conversion device that connects devices having different protocols without a transport layer.

0002

[Prior Art] Conventionally, in this type of protocol conversion device, since there is a protocol higher than the transport layer, delivery confirmation is always performed between each other, and the protocol conversion unit converts the message received from the source device. It was sent as is to the destination device.

0003

[Problems to be Solved by the Invention] The conventional protocol conversion device described above assumes that delivery confirmation is performed using the upper layer protocol, and sends the received message as is to the transfer destination. If a protocol is converted between devices that do not have a protocol, and the transmission becomes impossible due to the communication status of the transfer destination, the transmitted message will remain in the protocol conversion device.
As a result, it has the disadvantage that the message cannot be sent to the forwarding destination and is discarded.

[0004] An object of the present invention is to provide a protocol conversion device that can prevent messages from being discarded due to stagnation even when devices that do not have an upper protocol layer and have different protocols are connected. It's about doing.

[0005]

[Means for Solving the Problems] The protocol conversion device of the present invention includes (A) a first transmission waiting message storage area for temporarily storing a received message from the first device; (B) a first message storage area for temporarily storing a message received from the first device; a second waiting-to-send message storage area for temporarily storing messages received from the first device; a first communication control unit that stores a received message from the first device in the transmission waiting message storage area, reads out the received message from the first device and outputs it as a received message when the input restriction is lifted; , (D) performs communication control facing the second device, and when receiving input restrictions on the received message from the second device, transfers the received message from the second device to the transmission waiting message storage area. (E) a second communication control unit that reads out a received message from the second device and outputs it as a received message when the input restriction is lifted; receives the message, converts the protocol format of the first device into the protocol format of the second device, outputs it to the second communication control unit, and outputs the message from the second communication control unit. a protocol conversion unit that receives a received message, converts a protocol format of the second device into a protocol format of the first device, and outputs the converted message to the first communication control unit; monitor the communication status, and
It is determined whether or not the input restriction should be performed on the communication control unit and the second communication control unit, and the input restriction is performed on the received message from the first device and the received message from the second device. and a state monitoring section that instructs the first communication control section and the second communication control section to perform the input regulation when it is necessary to perform the input regulation.

[0006]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a protocol conversion device according to the present invention.

In FIG. 1, communication control is performed between waiting-to-send message storage areas 4a and 4b for temporarily storing received messages, and opposing devices, and the received message is sent to a protocol converter 2. When the protocol-converted message is received and sent to the opposing device, and the received message is subject to input restrictions from the opposing device, the received message is stored in the transmission waiting message storage areas 4a and 4b, and the input restriction is disabled. Communication control units 1a and 1b that read the received message and output it as a received message when the message is released; communication control units 1a;
A protocol conversion unit 2 that receives the received message output from 1b, converts the protocol format, and outputs it, monitors the communication status of the protocol, and determines whether or not to restrict input to the communication control units 1a and 1b. The communication control unit 3 is comprised of a status monitoring unit 3 that determines the input regulation and instructs the communication control units 1a and 1b to perform input regulation when input regulation is necessary.

Next, the operation will be explained.

[0010] In FIG. 1, a communication control section 1a controls communication with an opposing device and sends a received message to a protocol conversion section 2. The protocol conversion unit 2 converts the protocol format of the message received from the communication control unit 1a into a message that matches the protocol format of the transfer destination device, and sends the message to the communication control unit 1b. Communication control unit 1
b performs communication control with the opposing device and sends the message received from the protocol converter 2 to the opposing device.

[0011] The status monitoring unit 3 monitors the execution status of the above-mentioned protocol, counts the number of messages received via the communication control unit 1a, and detects when the number of received messages exceeds a predetermined value. When this is detected, or when a busy notification is received from the transfer destination device, the communication control unit 1a is restricted from inputting messages.

[0012] When the communication control unit 1a receives the input restriction for the received message, the communication control unit 1a transfers the received message to the transmission waiting message storage area 4a.
Store in.

[0013] The status monitoring unit 3 sends a message to the communication control unit 1a when the number of messages received via the communication control unit 1a decreases or when there is a busy release notification from the transfer destination device. Remove restrictions on inputting messages. When receiving the release of the input restriction, the communication control unit 1a reads out the message stored in the waiting-to-send message storage area 4a and sends it to the communication control unit 1b via the protocol conversion unit 2.

The above explanation is based on the case where the protocol conversion unit 2 converts the protocol of a message received from the device facing the communication control unit 1a and sends it to the device facing the communication control unit 1b via the communication control unit 1b. However, in the case of this reverse direction, the same operation as above is performed.

In this way, by monitoring the line status of each protocol section and counting the number of messages that have been requested to be sent, it is possible to determine whether there is a busy notification from the transfer destination device or whether there is a message waiting to be sent to the transfer destination device. If the number exceeds the specified number, by restricting input to the source device, even if devices that do not have an upper protocol layer and have different protocols are connected, messages will not be discarded due to accumulation of messages. can be prevented.

[0016]

[Effects of the Invention] As explained above, the protocol conversion device of the present invention monitors the line status of each protocol section and counts the number of messages that have been requested to be sent. or when the number of messages waiting to be sent to the transfer destination device exceeds the specified number, by restricting input to the source device, even if devices that do not have an upper protocol layer and have different protocols are connected. This has the effect of preventing messages from being discarded due to accumulation of messages.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a protocol conversion device of the present invention.

[Explanation of symbols]

1a, 1b Communication control section 2 Protocol conversion section 3 Status monitoring section

Claims (1)

[Claims] Claim 1. A protocol conversion device that performs protocol conversion between a first device and a second device that do not have a transport layer and have different protocols, wherein: (A) a message received from the first device; (B) a second waiting-to-send message storage area for temporarily storing the received message from the second device; (C) facing the first device; performs communication control, stores the received message from the first device in the transmission waiting message storage area when receiving input restrictions on the received message from the first device, and when the input restriction is released; a first communication control unit that reads the received message from the first device and outputs it as a received message; (D) performs communication control facing the second device and inputs the received message from the second device; A second device that stores the received message from the second device in the transmission waiting message storage area when the restriction is received, and reads the received message from the second device and outputs it as a received message when the input restriction is lifted. (E) receiving the received message output from the first communication control unit, converting the protocol format of the first device into the protocol format of the second device; output to a second communication control unit, receive the received message output from the second communication control unit, and convert the protocol format of the second device into the protocol format of the first device; a protocol conversion unit that outputs an output to the first communication control unit; (F) monitoring a communication state of each of the protocols;
It is determined whether or not the input restriction should be performed on the communication control unit and the second communication control unit, and the input restriction is performed on the received message from the first device and the received message from the second device. 1. A protocol conversion device comprising: a status monitoring unit that instructs the first communication control unit and the second communication control unit to perform input regulation when input regulation needs to be performed.