JPS6243937A - Line diagnosing device - Google Patents

Abstract

PURPOSE:To generate simply an abnormal state and an abnormal sequence on a protocol by providing a synchronizing inspection circuit for a transmission data and a reception data flowing to an interface and a transmission circuit for the transmission data or the reception data and a data block processing circuit. CONSTITUTION:When a transmission data is inputted from a DTE and start-stop synchronization is applied by the synchronization inspection circuit 6, after the parity is checked by a parity checker 9, the data is transferred to a processing circuit 7 and stored in a memory 10. Then the data stored in the memory 10 is sent to a DCE via a transmission circuit 8 normally. In conducting the protocol test, a processor 11 applies the deletion, insertion, or change of the data, the result is sent from the transmission circuit 8 to the DCE or the data is not sent to the DCE. The processing along with the test condition as above is applied and the system is used to test various protocol as a line diagnosing device. Further, similar function is applied as to the reception data from the DCE.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a line diagnostic device used for protocol testing, communication fault testing, etc. in data communication equipment.

(Prior art) Conventionally, "
A signal that is located between a modem and a communication control device or a modem and a data terminal device in a communication system that performs communication using the start-stop synchronization method based on the ``interface between a modem and a communication control device and a data terminal device,'' and that flows through that interface. [See Figure 3 (a) and (b)] The line diagnostic equipment is connected to each device at the communication control equipment or data terminal equipment (hereinafter referred to as DTE) and modem (hereinafter referred to as DEC).
It has functions such as monitoring the signals flowing through the interface between the CRT and the CRT and displaying the signals on the screen of a cathode ray tube (hereinafter referred to as CRT) or importing them into memory.

Figure 4 shows the configuration of a conventional line diagnostic device.
Interface unit 1 inserted between E and DCE
Each data block is received by a framing circuit 2 for synchronizing with the transmitted data and received data taken in from the data block, and is stored in the data capture memory 3. Then, this data block is stored in a C
By transmitting the signal on the line to the RT control circuit 4 and displaying it on the screen of the CRT 5, the entire contents can be monitored and used for protocol tests, etc.
This operation is briefly illustrated in FIG. 5.

(Problem to be Solved by the Invention) However, when performing a protocol test by connecting data communication devices face-to-face, the test can be performed by generating a normal protocol sequence without any problem, but the test can be performed by generating an abnormal protocol sequence. There was a problem in that it was difficult to conduct a test by causing the problem to occur.

The present invention has been made to solve these problems, and an object of the present invention is to provide a line diagnostic device that can easily generate abnormal states and abnormal sequences in the protocol.

(Means for Solving All Problems) The present invention includes a synchronization verification circuit for transmission data and reception data flowing through an interface, a data block processing circuit, and a transmission circuit for transmission data or reception data.

(Function) After passing the transmission data from the DTE and the reception data from the DCE through the synchronization verification circuit and detecting all the data blocks,
The data is stored in memory, and the data is processed by deletion, insertion, modification, etc., data block deletion, new addition, partial modification, unprocessed relaying, etc., and sent to the DCE as transmission data. , each can be sent to the DTE as received data, so it is possible to completely delete, partially change, or delay a certain period of data blocks flowing from the transmitted data from the DTE or the received data from the DCE, and send the transmitted data to all the DCEs, etc. By transmitting the processed received data to the DTE, an abnormal state in the protocol sequence can be easily generated.

(Embodiment) FIG. 1 shows the configuration of an embodiment of the present invention.
A synchronization verification circuit 6 and a processing circuit 7 are included in the processing system for the transmission data signal from E and the processing system for the reception data signal from DCE.
A transmission circuit 8 is inserted, and the transmission data signal or the reception data signal can be processed.

In this embodiment configured as described above, when transmission data is input from the DTE and start-stop synchronization is established in the synchronization verification circuit 6, the parity checker 9 performs a parity check, and then
The data is transferred to the processing circuit 7 and stored in the memory 10. The data stored in the memory 10 is normally sent to the DCE via the transmitting circuit 8, but when performing a protocol test or the like, the data is deleted, inserted, modified, etc. by the processor 11 and sent from the transmitting circuit 8. DCE
It performs processing in accordance with test conditions, such as sending data to the iDCE or not sending it to the data i DCE, and can be used as a line diagnostic device for various protocol tests.

Note that the same function applies to data received from the DCE.

(Effect of the invention) As explained above, according to the present invention, DTE and DCE
It is possible to process the signal flowing through the interface between the two at the data block level, and it has the effect of allowing frames to be deleted, data within the frame to be changed, etc.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention, FIG. 2 is a signal processing system diagram in the present invention, and FIG. 3(a) is a DTE
Figure 3 shows the connection system between and DCE (bJ is DTE
System diagram when a line diagnostic device is connected between and DCE,
FIG. 4 is a schematic block diagram of a conventional line diagnostic device, and FIG. 5 is a signal processing system diagram in the conventional line diagnostic device. 6... Synchronization verification circuit, 7... Processing circuit, 8... Transmission circuit. Figure 1 Figure 2

Claims (1)

[Claims] In a line diagnostic device that is located between a modem and a communication control device or a modem and a data terminal device in a communication system that performs communication using a start-stop synchronization method, and connects each device with a signal flowing through the interface, the data terminal device synchronization verification means for receiving data characters and data blocks in start-stop synchronization with data transmitted from the modem, and receiving data characters and data blocks in start-stop synchronization with data received from the modem; processing means for storing data, etc. in a memory and performing processing such as deletion, insertion, modification, etc. on the data stored in the memory; and a processing means for transmitting the data in the memory as transmission data to the modem;
A line diagnostic device comprising: sending means for sending the data in the memory as received data to the data terminal device.