JPH0793613B2 - Automatic recovery method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a time division multiple access wireless communication system in which wireless communication is performed between one master station and a plurality of slave stations by burst signals. In regard to the above, the present invention relates to an automatic restoration means for detecting power-on at the time of power failure of the slave station and automatically restoring the transmission operation of the slave station.

(Prior Art) In recent years, various communication systems have been developed with the development of communication technology and diversification of communication needs, and among them, wireless communication adopting a time division multiple access (TDMA) method. There is a system. FIG. 6 shows an example of the configuration, and this system is composed of one master station A and a plurality of slave stations B1 to Bn arbitrarily distributed. Then, the master station A sends a time division multiplexed signal (TDM signal) consisting of a continuous wave to each of the slave stations B1 to Bn as shown in FIG. 7, and the slave stations B1 to Bn send to the master station A an eighth signal. Each slave station as shown in the figure
Time slot TS in which B1 to Bn are pre-assigned to each station
By transmitting a data signal composed of burst waves to 1 to TSn, mutual communication of data is performed between the master station A and each slave station B1 to Bn.

In this type of system, since the distance between the master station and each of the slave stations B1 to Bn is different for each slave station, there is a difference in the propagation time of the radio signal. Therefore, in each of the slave stations B1 to Bn, the transmission signal is transmitted to the master station A.
In order to prevent them from overlapping with each other, it is necessary to adjust the signal transmission timings at the time of installing the slave stations and set the optimum timings. So conventionally,
For example, as shown in FIG. 9, a control slot is provided in the TDMA signal transmitted from each slave station B1 to Bn to the master station A, and when the slave station Bi is newly installed, the slave slot is used by using this control slot. Station
A burst signal for adjustment is sent from Bi to master station A. Then, the master station A detects the deviation amount of the reception timing of the burst signal for adjustment from the regular reception timing,
The detection result of this deviation amount is notified from the master station A to the slave station Bi using the control slot of the TDM signal (FIG. 7) and displayed on the display device or the like. Then, the maintenance staff of the slave station Bi manually sets switches such as a DIP switch according to the amount of deviation displayed on the display or the like to set the transmission timing of the slave station Bi. By doing so, it is possible to perform communication in the master station A without the transmission signals from a plurality of slave stations using adjacent time slots overlapping each other.

By the way, some systems of this kind are provided with an automatic recovery means for coping with a power failure accident or the like. This automatic resetting means monitors, for example, the power-on after the occurrence of a power failure, and when the power-on is detected, the data transmission time slots TS1 to TSn assigned according to the transmission timing information being set by the switch at that time are assigned. The transmission operation is automatically restarted. If such a means is provided, it is not necessary to send a maintenance worker to the slave station to perform a recovery operation every time a power failure or the like occurs, and the transmission operation can be easily and quickly restored.

(Problems to be solved by the invention) However, since the conventional automatic recovery method of this kind operates unconditionally when the power is turned on, for example, at the time of initial supplement of transmission timing or supplement compensation of transmission timing due to maintenance, It also operates when the power is turned on before the transmission timing setting is completed. In such a case, the slave station starts the transmission operation according to the uncertain transmission timing information, and this transmission adversely affects the transmission signals of other slave stations, increasing the transmission error and in the worst case, the line. It was very unfavorable because it could lead to disconnection.

Therefore, the present invention pays attention to such a situation and prevents the slave station from performing the transmission operation even when the power is turned on before the completion of the transmission timing setting, thereby preventing the transmission signals of other slave stations from being adversely affected. It is an object of the present invention to provide an automatic return method capable of stably maintaining the system operation.

[Structure of the Invention] (Means for Solving the Problem) The present invention is provided with one master station and a plurality of slave stations, and each slave station automatically performs a transmission operation according to parameter information being set when the power is turned on. In a time-division multiple access wireless communication system having an automatic restoration means for starting, a completion information storage means and a restoration prohibition means are provided, and when the setting of the parameter information is completed, the information to that effect is stored as the completion information storage. Stored in the means, and when the power is turned on, the return prohibition means determines whether or not the setting of the parameter information is completed from the stored contents of the completion information storage means,
When it is not completed, the recovery operation by the automatic recovery means is prohibited.

(Operation) As a result, according to the present invention, even if the power is turned on before the completion of the transmission timing setting of the slave station, if the transmission timing setting is not completed, the restoration operation by the automatic restoration means is prohibited. Therefore, it is possible to reliably prevent the problem that the transmission is started at an uncertain transmission timing. Therefore, there is no fear of adversely affecting the transmission signals of other slave stations, and thereby the operation of the system can be stably maintained.

(Embodiment) FIG. 1 shows the configuration of a slave station to which the automatic restoration method according to an embodiment of the present invention is applied. In the figure, for convenience of explanation, only one of the plurality of slave stations is shown.

This slave station is provided with a wireless line terminating device 10, a modulation / demodulation device 11 for modulating / demodulating a transmission / reception signal, a wireless transmission / reception device 13 having an antenna 12, an input operation unit such as a key switch and an output display unit such as a display. And a console 14.

Of these, the wireless line terminal 10 includes a multiplexer 15 and a demultiplexer 1 that multiplex transmission signals and demultiplex received TDM signals.
6 and a plurality of interfaces 17 connected to the multiplexing unit 15 and the demultiplexing unit 16 via a signal bus. These interfaces 17 are connected to a terminal device 19 via a line 18.
Are connected respectively. In addition, the wireless line terminal 10
Is a non-volatile memory including the control unit 20 and, for example, an E ² PROM.
21 and a transmission timing variable unit 22. The transmission timing varying unit 22 is composed of a phase shift circuit that varies the transmission phase of the transmission signal and a bit delay circuit that varies the transmission timing of the transmission signal in bit units. The non-volatile memory 21 includes the transmission timing variable unit.
It stores the amount of phase shift and bit delay set in 22, that is, the transmission timing information.
have. The completion flag 21a is set when the transmission timing setting is completed.

By the way, the control unit 20 has, for example, a microcomputer as a main control unit, and in addition to a control unit related to normal data transmission operation and a control unit related to supplement of transmission timing, an automatic restoration control unit 20a, Restoration prohibition means 2
0b and respectively. The automatic return control means 20a is
When the power-on is detected, the transmission timing information is read from the non-volatile memory 21, the phase shift amount and the bit delay amount of the transmission timing varying unit 22 are set according to this information, and then the data transmission / reception operation is started. Further, the recovery prohibiting means 20b determines whether the setting of the transmission timing is completed from the state of the completion flag 21a of the nonvolatile memory 21 when the power-on is detected, and determines that the setting is not completed. In this case, the recovery operation by the automatic recovery control means 20a is prohibited.

Now, in such a configuration, when the transmission timing of the slave station is first captured, it is performed as follows. That is, in the case of initial capture, the maintenance staff inputs the distance from the master station to this slave station by using the key switch of the console 14. Then, the control unit 20 of the wireless line terminal 10 calculates the propagation time (the number of bits) of the signal corresponding to this distance, and determines the rough transmission timing of the own station on the TDMA frame based on this calculated value. Then, this timing is set in the bit delay circuit of the transmission timing varying unit 22 and stored in the non-volatile memory 21.

In this state, the master station (not shown) first creates a timing adjustment control signal for adjusting the phase shift. FIG. 4 (b) shows the structure, in which the ID number bit, the ID number of the slave station is inserted, and the leading adjustment type bit of the instruction information of 4 bits corresponds to the phase adjustment instruction. The final adjustment start end bit of the instruction information is set to "0" corresponding to the adjustment start instruction while being set to "0". Then, this control signal is inserted into the control slot of the TDM signal shown in FIG. 4 (a) and transmitted to the slave station.

On the other hand, the control unit 20 of the slave station monitors the arrival of the phase shift adjustment instruction from the master station in step 2a as shown in FIG. In this state, when the timing adjustment control signal addressed to the own station arrives and the instruction for phase adjustment is recognized from the instruction information, the process proceeds to step 2b, and the burst signal for phase adjustment is transmitted here. That is, assuming that the phase can be adjusted in 1/20 bit units, the phase shift amount of the phase shift circuit 22a of the transmission timing varying unit 22 is set to 10/20, and in this state, as shown in FIG. The phase adjustment burst signal shown is inserted into the control slot AQ of the TDMA frame shown in FIG.

Then, the master station, after transmitting the timing adjustment control signal, from the reception timing of the phase adjustment burst signal inserted in the control slot of the TDMA signal coming from the slave station, the phase relative to the regular reception timing of this reception timing. The amount of deviation is detected. Then, a phase correction value is obtained from this phase shift amount, and this phase correction value is inserted into the phase shift information bit of the timing adjustment control signal shown in FIG. 4 (b) and sent to the slave station. For example, if the reception timing of the burst signal for phase adjustment is 5/20 bits behind the regular reception timing, the transmission phase of the slave station needs to be advanced by 5/20 bits, so the control unit
20 sends the phase correction value of "-5/20 bits" to the slave station.

On the other hand, the control unit 20 of the slave station performs the arrival monitoring of the phase correction value and the arrival monitoring of the bit shift adjustment instruction in step 2c and step 2e after transmitting the burst signal for phase adjustment, and in this state. When the master station sends the phase correction value destined for itself, shifts to step 2d, where the above-mentioned correction value −5/20 bits is added to the initial phase shift amount of 10/20 bits, and the phase shift is performed. The phase shift amount of the circuit is corrected to 5/20 bits which is the above addition result. Then, the transmission phase of the slave station is adjusted so that the phase difference becomes zero with respect to the reference phase in the master station.

After the phase correction, the slave station returns to step 2b and sends the phase adjustment burst signal again to the master station with the corrected phase. Then, when the phase correction value is sent again from the master station, the phase amount of the phase circuit is readjusted according to this phase correction value until the phase difference detected by the master station becomes zero or more. The operation of is repeated.

Now, when the phase difference becomes zero by the above phase adjustment, the master station sets the first adjustment type bit of the 4-bit instruction information to "1" corresponding to the bit adjustment instruction,
This timing adjustment control signal is sent to the slave station.
On the other hand, when the control unit 20 of the slave station detects the arrival of the control signal instructing the bit adjustment in step 2e, it determines that the phase adjustment is completed and starts the control for the bit adjustment. That is, first, in step 2f, a bit adjustment burst signal composed of a predetermined synchronization pattern (SYNC pattern) and the ID number of the own station as shown in FIG. 5 (c) is generated, and this signal is used for controlling the TDMA signal. It is inserted into slot AQ and sent to the master station. Then, when the burst signal for bit adjustment arrives from the slave station, the master station detects the bit shift amount from the reception timing of the synchronization pattern with respect to the regular reception timing. Then, a bit shift correction value for making the bit shift amount zero is obtained, and this correction value is inserted into the bit shift information bit of the timing adjustment control signal shown in FIG. Send out. For example, if the reception timing of the bit adjustment burst signal is 9 bits earlier than the regular reception timing, the transmission timing of the slave station needs to be delayed by 9 bits.
The master station sends a bit correction value of "+9 bits" to the slave station.

On the other hand, the control unit 20 of the slave station performs the arrival monitoring of the bit correction value and the arrival instruction of the completion instruction in step 2g and step 2i after the transmission of the bit adjusting burst signal, and in this state from the master station. Bit correction value for own station (+9
(Bit) is sent, the process proceeds to step 2h, where the delay amount of the bit delay circuit is further delayed by 9 bits from the initial value currently set, that is, the value calculated from the distance previously. Then, the transmission timing of the slave station is adjusted so that the bit shift becomes zero with respect to the reference timing in the master station. Then, the control unit 20 of the slave station returns to step 2f and retransmits the bit adjustment burst signal to the master station at the transmission timing after the bit shift correction. Then, the master station confirms that the bit shift has disappeared from the reception timing of the bit adjustment burst signal retransmitted from the slave station, and then sets the adjustment start / end bit in the instruction information of the timing adjustment control signal to the completion instruction. Set to the corresponding "1" and send to the slave station.

On the other hand, the control unit 20 of the slave station gives the completion instruction step
If it is detected in 2i, the process proceeds to step 2j, where the transmission timing information set in the transmission timing varying unit 22 is first stored in the non-volatile memory 21, and then the completion flag of the non-volatile memory 21 is set to "1" in step 2k. Set to ". Then, the non-volatile memory 21 stores the fact that the setting of the transmission timing is completed.

By the way, it is assumed that the power supply is temporarily interrupted due to a power failure accident while the transmission timing is being set, and then restored. Then, the control unit 20 of the slave station detects this power restoration and starts the automatic restoration control. That is, as shown in FIG. 3, after initializing each part of the apparatus in step 3a, first in step 3b, the state of the completion flag 21a of the nonvolatile memory 21 is input, and in step 3c, the transmission timing is changed from the state of this completion flag. It is determined whether or not the setting of is completed. Then, if the completion flag 21a is set to "1", it is determined that the setting of the transmission timing has been completed, and the process proceeds to step 3d, in which the transmission timing information is read from the nonvolatile memory 21. hand,
In step 3e, according to this information, the transmission timing changing unit 22
The phase shift amount and the bit delay amount are set in the phase shift circuit and the bit delay circuit, respectively, and then the process proceeds to the data transmission / reception control. On the other hand, if the completion flag 21a is "0", it is determined that the setting of the transmission timing is not completed, the automatic return control is stopped, and the transmission timing acquisition control is performed.

Therefore, as described above, when the power is temporarily cut off during the setting of the transmission timing and then restored, "1" is not set in the completion flag 21a, and thus the control unit 20 sets the completion flag 21a. From the state, it is judged that the setting of the transmission timing is not completed yet, and the automatic restoration is not performed. Therefore, there is no problem that the transmission is performed at an uncertain transmission timing, and there is no fear that the parent station will interfere with the receiving operation of the transmission signal from another child station.

As described above, according to the present embodiment, the non-volatile memory 21 is provided with the completion flag 21a that is set only when the setting of the transmission timing is completed, and when the power is turned on, the transmission timing is first changed from the state of the completion flag 21a. It is determined whether or not the setting of is completed, and if it is determined that the setting is not completed, the automatic return operation is not performed.
The transmission is not performed according to the uncertain transmission timing, and as a result, there is no fear that the master device adversely affects the transmission signals from other slave stations. Therefore, the transmission operation of the system can be kept stable, and a highly reliable system can be provided.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the case where the power failure occurs at the initial acquisition of the transmission timing has been described as an example, but the same applies to the case where the power failure occurs when the transmission timing is corrected and acquired after the operation is started. It can also be applied to the case where the power is turned on before setting the transmission timing at the time of new installation of the above. Further, in the above-mentioned embodiment, the case where the transmission timing is automatically set according to the transmission timing acquisition control procedure between the master station and the slave station is taken as an example, but the maintenance staff at the slave station operates the dip switch or the like. The same applies when the transmission timing is set manually. In addition, the procedure and contents of the automatic restoration control, the configuration and procedure of the restoration prohibiting means, etc. can be variously modified and implemented without departing from the scope of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, the completion information storage means and the return prohibition means are provided, and when the setting of the parameter information is completed, the information to that effect is provided to the completion information storage means. When the power is turned on, the return prohibiting means determines whether or not the setting of the parameter information is completed from the stored contents of the completion information storing means,
If it is not completed, it is possible to prevent the slave station from performing the transmission operation even if the power is turned on before the completion of the transmission timing setting by prohibiting the restoration operation by the automatic restoration means. As a result, it is possible to provide an automatic restoration method capable of stably maintaining the operation of the system without adversely affecting the transmission signals of other slave stations.

[Brief description of drawings]

FIG. 1 to FIG. 5 are for explaining an automatic return system in one embodiment of the present invention, and FIG. 1 is a functional block diagram showing a configuration of a slave station to which the system is applied, FIG. 2 and FIG. Three
FIG. 4 is a flow chart showing a control procedure in the control unit of the slave station, FIGS. 4 and 5 are frame configuration diagrams of TDM signals and TDMA signals, respectively, and FIGS. 6 to 9 are used for explaining the prior art. FIG. 6 is a schematic configuration diagram of a time division multiple access wireless communication system, FIG. 7 is a frame configuration diagram of a TDM signal, FIG. 8 is a timing diagram showing a transmission mode of each slave station, and FIG. 9 is a frame of a TDMA signal. It is a block diagram. 10 ... Wireless terminal device, 11 ... Modulator / demodulator, 12 ... Antenna, 13 ... Wireless transceiver, 14 ... Console, 15
...... Multiplexing unit, 16 …… Separation unit, 17 …… Interface,
18 …… line, 19 …… terminal device, 20 …… control unit, 20a ……
Automatic recovery control means, 20b ... Recovery prohibition means, 21 ... Nonvolatile memory, 21a ... Complete flag, 22 ... Transmission timing variable section.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akito Oyamada, 1-chome, 3-1, Asahigaoka, Hino-shi, Tokyo Inside the Toshiba Hino Plant, a stock company (72) Inventor Yukari Osawa, 3-chome, Asahigaoka, Hino, Tokyo 1 Toshiba Corporation Hino Factory (56) References JP-A-62-128632 (JP, A)

Claims (1)

[Claims] 1. A time-division multiple access having one master station and a plurality of slave stations, and each slave station having an automatic restoration means for automatically starting a transmission operation according to parameter information being set when the power is turned on. In the wireless communication system, when the setting of the parameter information is completed, completion information storage means for storing information to that effect, and when the power is turned on, the setting information of the parameter information is completed from the stored contents of the completion information storage means. It is determined whether or not it is present, and if it is not completed, a return inhibiting means for inhibiting the return operation by the automatic returning means is provided.