JPS632184B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display method for a signal monitor device, and more particularly to a display method for a signal monitor device that monitors the status of signal transmission and reception within a digital data communication network.

Conventionally, signal monitoring devices are known that are configured to display input serial signals using a cathode ray tube oscilloscope, online data scope, etc.
For example, it is difficult to identify characters in the waveform displayed on an oscilloscope, and it is difficult to identify bit-by-bit changes in the waveform just by character display on the data scope. Furthermore, it has not been possible with conventional signal monitoring devices to macroscopically grasp the state of data transmission and reception, and to roughly grasp the time relationship of transmitted and received data, the locations where errors occur, and the like.

The present invention eliminates the above-mentioned drawbacks of the conventional signal monitoring device, and displays a signal train flowing within a digital data communication network together with a 1-bit waveform display as well as a character display. It is an object of the present invention to provide a display method for a signal monitoring device that allows a wider understanding of the state of signal transmission and reception between the two.

The above object of the present invention is to provide an interface circuit that is connected to a data transmission line and draws in data signals flowing through the transmission line, and a character group that identifies a group of characters based on a predetermined convention from an output signal string of the interface circuit. In a signal monitoring device having an identification circuit, a display device, and a control circuit for controlling these, when displaying the data signal flowing through the transmission path, the signal is displayed in a waveform corresponding to one bit, and the signal is This is achieved by a display method for a signal monitor device that is characterized in that it identifies the characters included in the image and also displays the characters.

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

FIG. 1 is a block diagram showing the main parts of an embodiment of the present invention as a device for displaying a signal string on a data exchange line. The envelope format signal used in the data exchange line has F bits and S bits (control information) before and after the data bits.
are attached to each. In the figure, 1 is an interface unit that detects the envelope signal and separates the data and control information therein, 2 is a character identification circuit that identifies characters from the separated data signal string, and 3 is an interface. This is a buffer memory for storing the S bit as control information which is the output of the unit 1 and the data and level/character identification bit which are the output of the character identification circuit 2. Further, reference numeral 4 denotes a processing section which has a built-in microprocessor and reads the contents of the buffer memory 3 under program control, edits it, and displays it on the display section 6 via the display control section 5.

A signal drawn in from a data exchange line is subjected to envelope signal identification in the interface section 1, and the identified envelope signal is separated into data and control signals and output separately. The control signal is written as is at a predetermined location in the buffer memory 3, and the data is input to the character identification circuit 2 for character identification, and then is written to a predetermined location in the buffer memory 3 as data in 8-bit units and level/character identification bits. Write. At this time, in order to match the time axis of the S bit as control information with the data bit, it is necessary to hold one bit for a time equivalent to six bits and display it as a level signal.

For example, if the data exchange line is a synchronous line, the character identification circuit 2 detects a synchronous pattern according to the JIS7 unit code specified by the 8-bit code to perform character identification, and thereafter converts the data signal in 8-bit units. Separate columns and write to buffer memory 3. At this time, all 8 bits are “1”
Or, if all of them are "0", this is determined to be a level and the level/character identification bit is written as "0", for example. Otherwise, it is determined to be a character and the level/character identification bit is written as "1", for example. It is added to the 8-bit data and written. If the data exchange line is an asynchronous line, a start/stop bit is detected, character identification is performed, and the data signal string is divided into 8-bit units and written into the buffer memory 3.

In this case, data whose characters cannot be identified are determined to be levels, and data whose characters can be identified are determined to be characters, and level/character identification bits are added and written to the 8-bit data.

The 8-bit data individually written in the buffer memory 3, the S bit as control information, and the level/character identification bit are read via the bus line under program control by the processing section 4.
The data is edited and simultaneously displayed on the display section 6 in letters or numbers via the display control section 5 in association with the waveform display of the data.

FIG. 2 shows the processing flow of the program control described above. At step 11, 8-bit data, the S bit and the level/character identification bit are read from the buffer memory 3, and at step 12, the level and character are determined. When the level/character identification bit is “0”, it is determined to be level, and 1
In step 3, data and S bits are edited to display waveforms. When the level/character identification bit is "1", it is determined to be a character, and after converting the JIS 7 bit code into a code for display at step 14, editing is performed at step 15 to display the character. Next, it is checked at 16 whether reading of all the data has been completed, and if YES, the data and S bit waveforms are displayed at 17, and the characters of the data are displayed at 18 on the same display screen.

FIG. 3 shows an example of the display described above. FIG. 3a shows an example in which data and S bit are displayed in parallel in 1-bit correspondence; the S bit is displayed as a waveform as a level signal, and the data is displayed as a character together with the waveform display. In the figure, 20,
24 represents the level, 21, 22, and 23 show an example of character display. For example, the waveform corresponding to 21 is K of the alpha alphabet expressed in the JIS7 unit code, 22 is the A of the alpha alphabet, and 23 is the number. This indicates that the character 8 is displayed.

Furthermore, Fig. 3b shows an example in which n bits of each waveform of the data and S bits displayed in Fig. 3a are converted into 1-bit level or character information and displayed in compressed form. be. In the figure, 34 and 37 represent levels, 36 represents character presence information, and 35
For example, display “Cl” at the top of the waveform and set it separately.
40, specific characters are displayed. 31, 32, and 33 represent timing sections with arrows and symbols T1, T2, and T3, and 4
A specific timing value is displayed as 1.

By adopting such a display method, it becomes possible not only to check the detailed contents of each bit in the signal sequence, but also to understand the situation macroscopically.

Figure 4 shows the monitoring of envelope signals in a digital data communication network that accommodates synchronous terminals.
This shows an example in which 16 bits are converted to 1 bit and an upstream signal and a downstream signal are compressed and displayed at the same time. In the figure, T indicates data of the upstream signal, C indicates S bit of the upstream signal, R indicates data of the downstream signal, and I indicates S bit of the downstream signal.

In the above embodiment, the case where the signal monitoring device is connected to a single data exchange line was explained as an example, but the present invention connects the signal monitor device to a time division multiplex line and connects a specific channel in the line. It is also possible to extract and monitor the data signal in the channel. In this case, the signal monitoring device
a multiple line interface unit that is connected to the time division multiplex line and draws in signals on the line and outputs the signals to a multiplex synchronization circuit; and a channel that extracts a specified channel in the time division multiplex line based on the output of the multiple synchronization circuit. By adding an extraction circuit, it becomes possible to monitor as described above.

As described above, according to the present invention, there is provided an interface circuit that is connected to a data transmission path and draws in data signals flowing through the transmission path, and a character group that is generated based on a predetermined convention from the output signal string of the interface circuit. In a signal monitoring device having a character recognition circuit for identifying a character, a display device, and a control circuit for controlling these, when displaying a data signal flowing through the transmission path, the signal is displayed in a waveform corresponding to one bit, and Since the characters included in the signal are identified and the characters are displayed, it is now possible to easily observe and understand the signal sequence between the terminal and the exchange network in the data exchange network. , which has an extremely large practical effect. In particular, if a method is adopted that compresses and displays the data, it will be possible to observe signals over a relatively long period of time, which will have an even greater practical effect in that it will be possible to grasp a wider range of conditions. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main parts of a signal monitoring device showing an embodiment of the present invention, FIG. 2 is a processing flowchart thereof, and FIGS. 3 and 4 are diagrams showing examples of display screens, respectively. 1: Interface part, 2: Character identification circuit,
3: Buffer memory, 4: Processing section, 5: Display control section, 6: Display section.

Claims (1)

[Claims] 1 an interface circuit connected to a data transmission path and drawing in data signals flowing through the transmission path;
In a signal monitoring device that includes a character identification circuit that identifies a character group based on a predetermined convention from an output signal string of the interface circuit, a display device, and a control circuit that controls these, a data signal flowing through the transmission path is provided. 1. A display method for a signal monitor device, characterized in that when displaying a signal, the signal is displayed in a waveform corresponding to one bit, and characters included in the signal are identified and characters are displayed.