JPS6159587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an error detection method for monitoring an abnormal operation of a facsimile machine itself.

In conventional facsimile equipment, errors in the data processing system, such as modem clockdown, data compression, decompressor failure, line buffer failure, etc., are fixed by monitoring the transmission and reception time between units for one page of data within the facsimile machine. 1 in time
If the page transmission/reception completion signal is not transmitted between units, this is determined as an error in the data processing system. When such an error is detected, the transmitting/receiving operation is interrupted and the system power is turned off.

Therefore, even if an error occurs in data transmission/reception near the beginning of one page, the error is detected and the line is disconnected after the transmission/reception time for one page has passed, resulting in a large time lag and being uneconomical.

An object of the present invention is to detect malfunctions of facsimile devices at an early stage.

In order to achieve the above object, in the present invention,
Errors in a facsimile device during data transmission or data reception are determined by monitoring the flow of data within the facsimile device over time in units of one line or several lines. By monitoring each line in this way, the time lag until the line is disconnected when an error occurs is shortened.

Time monitoring for each line of data can be easily performed by monitoring the transfer time of the line buffer memory and the transfer time of the buffer memory in the data compression/decompression device.

Next, embodiments of the present invention will be described with reference to the drawings. First, error checking during transmission will be explained with reference to FIG. 1a showing the configuration of the transmitting device. At the start of the transmission operation, the system control unit SCU, which is a microcomputer system whose main elements are ROM, RAM, and CPU, is switched to the line control unit NCU.
to connect the line to the facsimile side. Next, an operation start instruction is given to the line buffer RWB, and at the same time, the reading unit VPU is started. The reading unit VPU reads each line of the original one bit at a time and sends it to the line buffer RWB as calligraphic data. Line buffer RWB stores the sent data in its own memory and advances the address by 1. This operation continues until the end of one line. When one line of data is held in memory within line buffer RWB, line buffer RWB sets a status flag. When the SCU recognizes that this status flag has been set, it instructs the data compressor of the data compressor/decompressor DCR to start encoding. The data compressor, which has been given an instruction to start encoding, sends a drawing data request signal to the line buffer, takes the data into its own memory, and starts encoding it in the encoding circuit. At this time, when the data compressor finishes taking in the data, the line buffer RWB drops the status flag. When the SCU recognizes that this status flag has fallen, it again instructs the reading unit VPU to read the next line. Further, a data request signal from the data compressor to the line buffer RWB is generated every time one line of coded data is sent to the line. The above operations are performed continuously until the transmission operation is completed.

In the above operation, the time from the start of reading until the RWB status flag of the line buffer is set is a value determined by the reading speed. Therefore, the SCU can instrument this time by monitoring the status flag of the line buffer RWB, and if the specified time is exceeded, it can detect that an error has occurred in the reading section VPU, the line buffer RWB, or a combination thereof. Data request signals from the data compressor to line buffer RWB are continuous within a maximum time interval determined by the longest number of bits of coded data and the data transmission rate (BPS). Therefore, the time from when the line buffer RWB status flag goes up to when it goes down again will not exceed the above time, so measure it, and if it exceeds it, either the line buffer RWB, data compressor, modem MOD modulator, or It is detected that an error has occurred in that combination. If an error occurs in the data processing system, the control unit instructs the NCU to switch the line to the telephone side and stops operation.
Figure 1b shows the flow of this error detection sequence in the SCU.

Next, error checking during reception will be explained with reference to FIG. 2a showing the configuration of the receiving device. At the start of the reception operation, the SCU instructs the NCU to connect the line to the facsimile side. Next, an instruction to start decoding is given to the data expander of the DCR, and at the same time an instruction to start operation is given to the line buffer RWB. When one line of drawing data is set in its own buffer, the data expander applies a data transfer signal to the line buffer RWB and sends out the data. At the same time, decoding of the next line is started. Line buffer RWB sets a status flag when it receives calligraphic data. When the SCU recognizes that the line buffer status flag is set, it gives an instruction to the writing unit WE to start operation. The line buffer RWB sends drawing data one bit at a time in response to the operation of the writing section WE. Thereafter, this operation is continuously performed until writing of one line of drawing data is completed. When writing for one line is completed, a writing end signal is sent from the writing section to the line buffer. Upon receiving the write end signal, line buffer RWB lowers the status flag. Thereafter, the above operations are continuously performed until the reception operation is completed. Further, a data transfer signal from the data expander to the line buffer RWB is generated every time one line of coded data is decoded. In the above operation, the data transfer signal from the data expander to the line buffer WRB continues within the maximum time interval determined by the maximum number of bits of the coded data and the data transmission rate.

Therefore, the time interval at which the line buffer RWB status flag is set will not exceed the above time, so measure this, and if it exceeds the time interval, the line buffer RWB will be set.
It is possible to detect that an error has occurred in any one of the RWB, DCR data decompressor, MOD demodulator, or a combination thereof. Next is the line battle RWB.
The time from when the status flag is raised and writing is started until the status flag is lowered again is a value determined by the writing speed. Therefore
The SCU measures this time by monitoring the status flag of the line buffer RWB, and if it exceeds the specified time, the line buffer RWB, writing section WE,
It is possible to detect that an error has occurred in either one or a combination thereof. When an error occurs in the data processing system, the SCU instructs the NCU to switch the line to the telephone side and stops operation. Figure 2b shows the flow of this error detection sequence for the SCU.

Note that in the above embodiment, the line buffer
In addition to monitoring the data sending time on a line-by-line basis in the RWB transfer step,
Alternatively, as shown by dotted lines in FIGS. 1a and 2a, the data sending time may be monitored line by line at the transfer step of the DCR buffer memory.

As described above, errors in the entire data processing system can be detected by monitoring the inflow/output time of the calligraphic data in the middle of the flow of the calligraphic data.
Since error detection is performed by monitoring the inflow/output time of one line or several lines of drawing data, it can be carried out in a short time after error detection occurs. Therefore, it is possible to minimize the time lag from the occurrence of an error until the line is disconnected.

[Brief explanation of the drawing]

FIG. 1a is a block diagram showing the configuration of the transmitter side of the facsimile apparatus, and FIG. 1b is a flowchart showing the abnormality detection operation sequence of the system control unit SCU. FIG. 2a is a block diagram showing the configuration of the receiving device side of the facsimile device;
FIG. 2b is a flowchart showing the abnormality detection operation sequence of the SCU. DCR: data compressor/expander, MOD: modem,
NCU: line control unit, SCU: system control unit, TIM: timer.

Claims (1)

[Claims] 1 Reading device, data compressor, modulator,
In a facsimile device equipped with at least one of a transmitting device consisting of an NCU, etc., and a receiving device consisting of an NCU, a demodulator, a data decompressor, a writing device, etc., the data transmission time within the facsimile device is in units of one line or several lines. An error detection method in a facsimile machine, which monitors and detects an abnormality in the transmitting device and the receiving device.