JP2624461B2 - Signal monitor for variable communication speed line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal monitor for a variable communication speed line, and more particularly to a signal monitor for monitoring a line for transmitting a data signal having a different communication speed on the same line in a time-division manner and displaying the transmission data in characters. Related to the device.

[0002]

2. Description of the Related Art A conventional signal monitoring apparatus includes a signal input means for inputting a data signal flowing through a data transmission line and a data code (bit code) identification for the input signal based on a preset communication speed. And a data display unit for visually displaying the identified data code as characters (including numbers) according to a specified code system. Examples of such a signal monitoring device are disclosed in JP-A-62-221239 and JP-B-63-221239.
No. 2184.

[0003]

In this conventional signal monitoring device, the communication speed set at the start of monitoring for each line cannot be changed during monitoring.
When the present invention is applied to a line that can change the communication speed in a time-division manner on the same line, such as the -232-C interface, there is a problem that a signal according to the communication speed changed from a set value cannot be normally identified with a data code. .

[0004]

SUMMARY OF THE INVENTION A signal monitoring apparatus for a communication speed variable line according to the present invention monitors a line transmitting data signals having different communication speeds on the same line in a time-division manner, and displays the transmission data in characters. In the monitor device, signal input means for connecting to the line and pulling in a data signal to be transmitted on the line, and all kinds of communication speeds which may vary as the communication speed of the data signal are respectively associated with each other. A plurality of types of data identification means corresponding to a plurality of single communication speeds for performing data code identification and error detection in parallel with each other based on the communication speed assigned to the data signal pulled in by the signal input means, Converts data codes output from each of a plurality of types of data identification means corresponding to a single communication speed into a character pattern based on a specified code system and generates error information. Together provided with all of the data identification unit content data display means for character display at the same time.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. The personal computer 10 and its keyboard 11 are connected by an RS232C interface signal line 12 to transmit an asynchronous data signal. The signal monitoring device according to the present embodiment includes a signal input unit 21 connected to the RS232C interface signal line 12 to be monitored and receiving the signal without affecting signal transmission between the personal computer 10 and the keyboard 11; Is input to the RS232C interface at 1200 bps, 2400 bps, 48
A data identification unit 22 that simultaneously samples at a plurality of sampling rates respectively corresponding to 00 bps and 9600 bps, identifies a start bit, a stop bit, and a data code bit, and generates error information if there is a data error such as a bit length or parity; A data display unit 23 for displaying data for each communication speed identified by the identification unit 22 as characters in a designated code system together with error information.

The data discriminating section 22 converts the data signals from the signal input section 21 into communication speeds of 9600 bpds and 4 respectively.
9600 bps identification circuits 221, 4 for identifying the value of each bit as 800 bps, 2400 bps, and 1200 bps and outputting the corresponding data code or error information
It has an 800 bps identification circuit 222, a 2400 bps identification circuit 223, a 1200 bps identification circuit 224, and a clock generation circuit 229 for supplying a sampling clock to these identification circuits.

Next, the operation will be described. RS2 to be monitored
When a data signal flows through the 32C interface signal line 12, the signal monitoring device 20 captures this data signal at the signal input unit 21, and the 9600 bps identification circuits 221 and 4800 bps identification circuits 222 and 2400b of the data identification unit 22.
ps identification circuit 223 and 1200 bps identification circuit 22
Distribute to 4. Each of the identification circuits (221 to 224) assumes a bit position of each component of the data signal according to a given clock, finds a bit value, and identifies a start bit, a data code, and a stop bit.
At this time, when the stop bit is not detected or when a parity violation is detected in the data code, corresponding error information is generated. The data display unit 23 displays each identification circuit (2
For example, a 7-bit data code (excluding a parity bit) is composed of two hexadecimal digits. If there is error information, the data code is embedded together with the error information, if any. Visual display on the display. FIG. 2 shows an example of a data display format on the data display unit 23.

[0009]

As described above, according to the present invention, data identification and error detection are performed by data identification means corresponding to a plurality of communication speeds at the same time, and data codes and error information corresponding to all communication speeds are displayed on the data display means. Since the characters are displayed at the same time, even if data signals with different communication speeds flow in a time-division manner during line monitoring, check the display contents of the data display section and select a display portion that supports communication speed without error. Thus, correct transmission data can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing an example of a data screen display format on a display unit of the embodiment of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 12 RS232C interface signal line 20 signal monitoring device 21 signal input unit 22 data identification unit 23 data display unit 221 9600 bps identification circuit 222 4800 bps identification circuit 223 2400 bps identification circuit 224 1200 bps identification circuit

Claims (1)

(57) [Claims] 1. A signal monitoring apparatus for monitoring a line transmitting data signals having different communication speeds in a time-division manner on the same line and displaying characters of the transmitted data, wherein the data is connected to the line and transmitted on the line. The signal input means for pulling in the signal, and the data signal pulled in by the signal input means are respectively assigned to each of all kinds of communication speeds which may be varied as the communication speed of the data signal, and are assigned to the self. A plurality of types of data identification means corresponding to a single communication speed, which perform data code identification and error detection in parallel with each other based on the communication speed, and a plurality of types of data identification means compatible with a single communication speed. Data which is converted into a character pattern based on a designated code system and character-displayed simultaneously with error information for all the data identification means. A signal monitoring device for a variable communication speed line, comprising: a display unit.