JP2573748B2 - Online data recorder for distributed processing system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed processing system, and more particularly to an online data recording apparatus.

[0002]

_2. Description of the Related Art As shown in FIG. 13, a conventional distributed processing system for information processing includes a computer 1 and n (n is a positive integer) terminal devices T ₁ , T _{2 to} Tn which are relatively limited in a premises. It is connected to a designated place by a high-speed transmission line, so that it can be used interchangeably, such as exchange of information, centralization of maintenance, and sharing of a database. The total length of the transmission line is a maximum of 1.5 km, and a speed up to 1 Mbit / s can be obtained relatively easily by digital transmission.
_{1 to} Bn, and one branch cable BCi (i =
1 to n) and a connector Ci (i = 1 to n) of one terminal device Ti (i = 1 to n) are connected to form a bus-shaped transmission path. Further, the signal flowing through the trunk cable 3 disappears without being reflected by the terminal circuit 4 in the terminal device Tn connected to the terminal of the trunk cable 3.

In such an information processing system, when a plurality of terminal devices start communicating with the computer 1 at the same time, data collision occurs because one transmission line is commonly used. Therefore, the computer 1 communicates with an arbitrary terminal device connected to the transmission path according to a predetermined transmission control procedure.

[0004] Next, a description will be given of failure processing of a transmission line in this distributed processing system. Due to a defect in the hardware or software of the computer 1 or any terminal device Ti, signals flowing on the trunk cable 3 may collide. When exchanging data with an arbitrary terminal device Ti, the computer 1 traces the exchange of communication as a part of network management and usually stores the trace in a memory in the computer 1 or a part of an external storage device. I have. By looking at this trace information, the cause of the failure can be analyzed.

[0005]

In a conventional failure processing on a transmission line in a distributed processing system, a trace function of a computer for performing network management is used. This trace function uses a memory in a computer or an external storage device.

[0006] In the case of maintenance, the memory in the computer or the external storage device is preferentially used in the work of the customer, and there is an upper limit on the storage capacity that can be mounted depending on the type of the computer. There are restrictions on securing. Also, letting a computer perform a tracing function is not preferred by customers because it degrades the performance of customer tasks.

Normally, it may take about 20 minutes to about 2 hours for an operator to find a fault after a fault has occurred on a transmission line. The storage capacity required during this time is about 180 Mbytes to 1140 Mbytes in a transmission path using 1 Mbit / sec and 10 bits per character. This is far beyond the storage capacity that can be secured for maintenance, and there is a problem that a recording method that overwrites a small storage capacity does not remain on the trace.

An object of the present invention is to provide an on-line data recording apparatus for a branch processing system in which line data is recorded using a digital audio device having a large storage capacity and line data is prevented from being lost when a transmission path failure occurs. Is to do.

[0009]

In order to achieve the above object, an on-line data recording apparatus for a branch processing system according to the present invention has a converter and a digital audio device, and a plurality of main cables connected to a computer. In an online data recording device used in a distributed processing system in which a terminal device is connected via a branch cable, a converter is connected to a branch cable connecting an arbitrary terminal device and a trunk cable, and is connected to an arbitrary terminal device and a computer. Has a function of converting online data transmitted between the digital audio device into a digital audio interface signal stored in the digital audio device and converting a signal reproduced from the digital audio device into online data. Equipment conversion It is connected to, together with the signals of converted digital audio interface for recording stored in the converter, and has a function of outputting to the transducer to reproduce the recorded stored signal.

[0010]

The converter 5 converts online data exchanged between the computer 1 and an arbitrary terminal device Ti into a digital audio interface signal, and the digital audio device 8 converts the digital audio data converted by the converter 5 into digital audio interface signals. Records and saves interface signals and saves data in the event of a transmission line failure.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention. In the figure, the present embodiment shows a branch box Bi of a trunk cable 3 and a connector Ci of an arbitrary terminal device Ti.
, The converter 5 and the digital audio device 8 are connected. 1 is a computer, 2 is a connector,
T _{1 to} Tn are terminal devices, C _{1 to} Cn are connectors, and BC ₁ to
BCn branch cable, B ₁ to Bn is a branched box.

The digital audio device 8 has a large storage capacity, for example, two hours, and further converts an analog signal into a digital audio interface by encoding an analog signal by applying an analog amplitude level to a digital level based on the sampling theorem. Function to directly input the optical signal of the digital interface and record it on a dedicated magnetic tape; function to reproduce from the dedicated magnetic tape, decode the digital code from the digital audio interface into a digital code, and return to an analog signal; A function of outputting an optical signal of the interface.

FIG. 2 is a block diagram showing the converter 5 of FIG. 1 in detail. The converter 5 includes a modulator for converting a serial signal on a transmission path to a digital audio interface, and a demodulator for converting a serial signal from the digital audio interface to a serial signal to be transmitted on the transmission path.

The modulating unit converts the line data SIF into a signal level in the converter, a line receiving circuit 14, a start-stop synchronization detecting circuit 16 for generating a buffer clock RT and line data RD from the line data SIF, and a line data RD. A buffer circuit 17 for temporarily storing the data, a multiplexing circuit 19 for synthesizing the buffer data BD and the clock information generated from the clock circuit 18, and a multiplexed data MUXD.
Is converted into a digital audio interface, and an optical transmitter 29 that converts digital output data DIGO into an optical signal. 6 is an optical cable, 15 and 24 are crystal oscillators, 25 is a frequency dividing circuit, 2
Six-leaf 1/6 frequency-divided signal, 27 is a 1/3 frequency-divided signal.

The demodulation unit includes an optical receiver 32 for receiving an optical signal reproduced from the digital audio device 8, a demodulation circuit 33 for converting digital input force data DIGI generated by the digital audio interface into a serial signal, and 16 A signal combining circuit 34 for separating clock information from the bit data DO and combining serial data before and after the clock information; a buffer circuit 35 for temporarily storing buffer data BWD; , And a line drive circuit 37 for converting the signal level in the converter 5 to the signal level on the transmission line. 7, an optical cable; and 31, an optical connector.

Next, the operation of this embodiment will be described with reference to FIGS.
This will be described with reference to FIG.

The operation of the modulator will be described with reference to FIGS. In FIG. 2, when operating the modulation section, the recording / reproduction switch 11 is manually set to the recording-side switch contact 12 side. Since the recording / reproduction switch 11 operates in conjunction with the recording / reproduction switch 21, the recording / reproduction switch 21 is automatically set to the recording-side switch contact 22 side.

Line data S branched from the trunk cable 3 by the branch connector Bi and flowing through the branch cable BCi
The IF is converted by the line receiving circuit 14 into a TTL signal level used in the converter 5.

As shown in FIG. 3, the start-stop synchronization detecting circuit 16 converts the line data SIF converted to the TTL signal level.
Is synchronized with the 1/16 frequency of the clock rt generated from the crystal oscillator 15 at the fall of the start bit STB. The line data SIF is read out at the rise of the 1/16 frequency of the synchronized clock rt, and becomes the line data RD from which distortion has been removed. The buffer clock RT is 1/16 of the clock rt synchronized with the line data RD.
This is a continuous clock in which the rising edge is shifted to the center of the line data RD in comparison with the phase of the divided frequency.

The buffer circuit 17 has a buffer clock R
The line data RD is written into the buffer by T. The buffer circuit 17 has a buffer capacity of 32 Kbits, and when the storage amount exceeds 16 Kbits, as shown in FIG. 4, synchronizes with the flag RF and the buffer clock BRCK, and continuously outputs buffer data BD for 24 bits. .

As shown in FIG. 5, the multiplexing circuit 19 combines 8 bits of control bits and 24 bits of buffer data BD to form 32 bits / 1 frame. The control bits are a 1-bit flag F for discriminating between valid data read from the buffer circuit 17 and invalid data created in the multiplexing circuit 19 to fill the idle time, and a clock circuit 18.
It consists of 1 and address A of the bit length indicating the start position of the read clock information, and reserved bits S of the clock data D ₃ to D ₀ and 2 bit length of 4 bits in length. Multiplexed data M
UXD is output to the modulation circuit in synchronization with the bit clock BCK. The first 16 bits of the 32 bits are data for the left channel Lch of the digital audio device, and the remaining 16 bits are data for the right channel Pch.

The modulation circuit 28 multiplexes the multiplexed data MU read out in synchronization with the bit clock BCK, as shown in FIG.
The XD is modulated by the digital audio interface during the one-channel clock LRCK, and the digital output data DIGO is output to the optical transmitter 29. FIG. 7 shows the waveforms of the multiplexed data MUXD and the digital output data DIGO.

FIG. 2 and FIGS. 8 to 12 show the operation of the demodulation unit.
This will be described with reference to FIG. In FIG. 2, when operating the demodulation unit, the recording / reproduction switch 11 is manually set to the reproduction-side switch contact 13 side. Since the recording / reproduction switch 11 operates in conjunction with the recording / reproduction switch 21, the recording / reproduction switch 21 is automatically set to the reproduction-side switch contact 23 side.

An optical signal reproduced from the digital audio device 8 is input to an optical receiver 32 and outputs digital input data DIGI to a demodulation circuit 33. FIG. 8 shows the waveforms of the digital input data DIGI and the 16-bit data DO demodulated by the demodulation circuit 33.

As shown in FIG. 9, the demodulation circuit 33 outputs 1/3 of 6.144 MHz output from the frequency dividing circuit 25.
The digital input data DIGI is read out in synchronization with the 1/2 frequency of the frequency-divided signal 27, and the digital audio interface signal is demodulated as shown in FIG. 16-bit data DO with synchronized timing clock BCO
Is output in the one-channel signal LR. Data status WC is 16-bit data DO in one channel signal LR.
Is output.

The signal coupling circuit 34 separates 8 control bits from the 16-bit data DO synchronized with the timing clock BCO, detects the address A indicating the start position of the clock information in the control bits, and sets a 4-bit length. The clock information D _{3 to} D ₀ are output to the clock information display circuit 20. The remaining 8 bits of the 16-bit data DO and the next 16-bit data D
The 16 bits of O are combined, and the 24-bit buffer data BWD combined in the input data status WC is written to the buffer circuit 35 with the buffer clock BWCK as shown in FIG.

The buffer circuit 35 has a buffer capacity of 32 Kbits. When the storage amount exceeds 16 Kbits, the buffer data SD is sent to the phase control circuit 36 in synchronization with the flag WF and the buffer clock ST2 as shown in FIG. Output.

The phase control circuit 36 synchronizes with the clock rt output from the crystal oscillator 15 at 1/16 frequency and outputs it to the line drive circuit 37.

The line drive circuit 37 converts the TTL signal level to the signal level of the line data SIF used on the trunk cable 3.

At the time of demodulation, if the line data SIF flows on the trunk cable 3, it collides with the signal flowing on the trunk cable 3 to cause a transmission path failure. Therefore, the branch cable BCi is disconnected from the branch connector Ci, and 9 and the branch cable 10
0 is connected to the branch connector Ci.

At the time of demodulation, the analyzer is connected to the connector 9 to analyze the collected line data.

[0032]

As described above, according to the present invention, a large amount of line data is recorded in a digital audio device having a storage capacity of, for example, two hours, so that line data in the event of a transmission path failure can be omitted. It has the effect of disappearing.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing details of the converter of FIG. 1;

FIG. 3 is a waveform diagram of a signal in a start-stop synchronization detection circuit of the converter.

FIG. 4 is a waveform diagram of a signal in a buffer circuit of the converter.

FIG. 5 is a waveform diagram of a signal in a multiplexing circuit of the converter.

FIG. 6 is a waveform diagram of a signal in a modulation circuit of the converter.

FIG. 7 is a waveform diagram of multiplexed data MUXD and digital output data DIGO.

FIG. 8 shows digital input data DIGI and demodulated 1
FIG. 6 is a waveform diagram with 6-bit data DO.

FIG. 9 is a waveform diagram of a signal in the optical receiver of the converter.

FIG. 10 is a waveform diagram of a signal in a demodulation circuit of the converter.

FIG. 11 is a waveform diagram of a signal in a signal coupling circuit of the converter.

FIG. 12 is a waveform diagram of a signal in a buffer circuit of the converter.

FIG. 13 is a block diagram showing a conventional distributed processing system.

[Explanation of symbols]

1 computer 2, 9, C ₁ to Cn connector 3 mains cable 4 termination circuit 5 transducers 6,7 cable 8 digital audio unit 10, BC ₁ ~BCn branch cable 11, 21 recording and reproduction switches 12 and 22 recording side switch contact 13 , 23 reproduction side switch contact 14 line receiving circuit 15, 24 crystal oscillator 16 start-stop synchronization detecting circuit 17, 35 buffer circuit 18 clock circuit 19 multiplexing circuit 20 clock information display circuit 25 frequency dividing circuit 26 1/6 frequency dividing signal 27 1 / 3 frequency-divided signal 28 modulation circuit 29 optical transmitter 30,31 optical connector 32 optical receiver 33 demodulation circuit 34 signal coupling circuit 36 phase control circuit 37 line drive circuit B _{1 to} Bn branch box T _{1 to} Tn terminal device

Claims (1)

(57) [Claims] 1. An online data recording apparatus for use in a distributed processing system having a converter and a digital audio device, wherein a plurality of terminal devices are connected to a main cable connected to a computer via a branch cable, respectively. Is connected to a branch cable connecting an arbitrary terminal device and a main cable, and converts online data transmitted between the arbitrary terminal device and the computer into a digital audio interface signal to be stored in the digital audio device. In addition, the digital audio device has a function of converting a signal reproduced from the digital audio device into online data. The digital audio device is connected to the converter and records and saves the digital audio interface signal converted by the converter. , That An online data recording apparatus for a distributed processing system, having a function of reproducing a signal recorded and stored in the apparatus and outputting the signal to a converter.