JPS60254931A - Fault monitor system for inductive communication system - Google Patents

Abstract

PURPOSE:To detect the fault of the whole device by rectifying a high-frequency signal from the transmitting device in a terminating set, returning its output voltage to the transmitting device side through an inductive communication line, and detecting the voltage at the high frequency signal feed terminal of the transmitting device. CONSTITUTION:The high frequency output signal of the transmitting device 1 is sent to the side of the terminating set 3 through a monitor device 4, feeder 6, matching device 2, and induction antenna line 5. At this time, the high frequency signal received by a terminating resistance 30 is converted by a rectifier 3 into a DC voltage, which is smoothed by a resistance 33 and a capacitor 34 and impressed to the antenna line 5. The voltage is applied to high frequency choke coils 23 and 24 through the matching transformer 20 of the matching device 2 to cut off its high frequency component, and then returned to the monitor device 4. The monitor device 4 cuts off the high frequency component of the voltage through high frequency choke coils 42 and 43, and said voltage is displayed on a voltmeter 44. If there is a decrease in the transmission output of the transmitting device 1 or an increase in transmission loss, the high frequency signal electric power received by the terminating resistance 30 decreases and the returned DC voltage drops. Therefore, the degree of the fault of the whole device is made clear from the voltage value on the voltmeter 44.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fault monitoring system for an inductive communication device that performs communication by inductive coupling of high-frequency signals.

[Technical background of the invention]

As is well known, this type of communication device feeds a high frequency signal to an inductive communication line installed between a transmitting device and a terminating device,
The high frequency signal is configured to be transmitted by inductive coupling to a receiving device close to the inductive communication line.

By the way, in this type of communication device, normal communication cannot be ensured if the power of the high-frequency signal transmitted from the transmitting device fluctuates, or if a problem occurs in the inductive antenna wire or the antenna system of the leaky coaxial cable, which is the inductive communication line. . Therefore, conventionally, a first monitoring system monitors the output current, output voltage, or output power of the transmitting device, and a second monitoring system monitors the failure state by directly measuring the continuity, insulation resistance, etc. of the inductive communication line.
There is a system in which a communication failure state of the entire device is monitored using these two monitoring systems.

[Problems with background technology].

However, if two systems of monitoring systems are used to monitor the status of communication failures as described above, the monitoring system becomes expensive, and problems related to the coupling relationship between the two, such as mismatch between the transmitter and the antenna system, become more expensive. The problem is that the extent of the failure cannot be detected. Furthermore, direct current monitoring of antenna systems has the problem that it is not possible to detect the extent of high-frequency disturbances such as increased transmission loss in inductive communication lines and fluctuations in characteristic impedance due to dirt or the like.

[Purpose of the invention]

The present invention eliminates the above-mentioned problems and eliminates high frequency interference.
It is an object of the present invention to provide a fault monitoring method for guided communication equipment that can detect faults in the entire equipment, including faults caused by damage or the coupling relationship between a transmitter and an antenna system, with an inexpensive configuration.

[Summary of the invention]

The present invention provides a rectifying means for rectifying a high frequency signal received from a transmitting device in a termination device, and returns the DC output voltage of the rectifying means to the transmitting device via an inductive communication line to feed the high frequency signal of the transmitting device. The above object is achieved by detecting the returned DC voltage at or near the end and monitoring the failure of the entire device based on the value of the detected DC voltage.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of an inductive communication device to which the present invention is applied, and can be roughly divided into transmitting device 1. Matching box 2
．． It is composed of a terminating device 3 and a monitoring device 4, and an inductive antenna wire 5 as an inductive communication line is laid between the matching box 2 and the terminating device 3.

Of these, the matching box 2 is a rectifier transformer I for impedance matching with the inductive antenna line 5.

It is equipped with a capacitor 21 and η for DC cutoff, and a high frequency choke coil n and sae for high frequency cutoff. Also,
The termination device 3 includes a termination resistor (9) and a step-up transformer 31 for boosting the high-frequency signal. A rectifier 32 that rectifies the boosted high frequency signal. The monitoring device 4 is equipped with a resistor for applying the rectified DC voltage to the induction antenna wire 5, and a capacitor for smoothing the DC voltage.The monitoring device 4 is also equipped with a capacitor 40 for DC cutoff and a 41° high frequency cutoff for high frequency cutoff. Choke coils 42 and 43° This choke coil 42,
A voltmeter 44 with an alarm contact is provided to monitor the output voltage of 43.

In such a configuration, the high frequency signal output from the transmitting device 1 is transmitted to the matching device 2 via the ant vision device 4 and the feeder line 6.
is input to the primary side of the matching transformer. Then, it is applied between the induction antenna lines via the secondary side of the matching transformer and transmitted to the termination device 3 side. If a receiving device (not shown) is close to the inductive antenna line 5 in this state, the high frequency signal is received by the receiving device by inductive coupling.

At this time, the high frequency signal received by the terminating resistor I of the terminating device 3 is boosted by the step-up transformer, then rectified by the rectifier 3 and converted into a DC voltage. Then, this DC voltage is smoothed by a resistor 33 and a capacitor M, and then applied to the induction antenna wire 5. The DC voltage applied to the induction antenna wire 5 is guided to the high frequency choke coil n, 24 via the secondary winding of the matching transformer of the matching box 2, where the high frequency component is blocked, and then the primary It is sent back to the monitoring device 4 via the side windings and the feed line 6.

Then, in the monitoring device 4, the DC voltage received from the power supply line 6 is input to the high frequency choke coils 42 and 43, the high frequency component is blocked by the coil, and the DC voltage is applied to both ends of the voltmeter 44. As a result, the DC voltage returned from the termination device 3 is displayed on the voltmeter 44.

If a failure occurs such as a decrease in the transmission output of the transmitter 1, a mismatch in the antenna system, or an increase in transmission loss of the inductive antenna wire 5, the high-frequency signal power received by the terminating resistor (2) decreases, and as a result, The DC voltage returned from the termination device 3 also decreases. Further, when the insulation between the lines is reduced due to a decrease in the insulating strength of the induction antenna wire 5, the voltage drop due to the resistor 33 increases, and in this case, the DC voltage returned from the termination device 3 also decreases.

Therefore, the degree of the failure can be known from the voltage value indicated by the voltmeter 44 of the monitoring device 4. In addition, if the indicated voltage value falls below a certain value, the voltmeter 44
An alarm can be issued by the alarm contact.

Note that the capacitors 21 and Z2 in the matching box 2 play the role of preventing backflow of the DC voltage returned from the termination device 3 and preventing short circuit between the positive side and the negative side.

By the way, although an inductive antenna wire is used as the inductive communication line in this embodiment, the same effect can be achieved even if a leaky coaxial cable is used.

〔Effect of the invention〕

As is clear from the above description, the present invention provides a rectifying means for rectifying a high frequency signal received from a transmitting device in a terminating device, and transmits the DC output voltage of the rectifying means to a high frequency signal feeding end through an inductive communication line. The returned DC voltage is detected at or near the high-frequency signal feeding end, and failures are monitored based on the value of the detected DC voltage. Therefore, failures in the entire device from the transmitting device to the antenna system can be detected very easily, and the monitoring system can also be made inexpensive.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Transmission device, 2... Matching box, 3... Termination device, 4... Monitoring device, 5... Inductive antenna line, 44...
··voltmeter.

Claims (3)

[Claims] (1) Inductive communication in which a high-frequency signal for communication is fed to an inductive communication line installed between a transmitting device and a terminal device, and the high-frequency signal for communication is transmitted by inductive coupling to a receiving device close to the inductive communication line. In the device, a rectifying means for rectifying the communication high frequency signal received by the terminal device is provided in the termination device, and the DC output voltage of this rectification means is applied to the inductive communication line, and the power supply end of the communication high frequency signal is A failure monitoring method for an inductive communication device, characterized in that the DC output voltage is detected at or near the DC output voltage, and communication failures in the entire device are monitored based on the value of the detected DC voltage. (2) A failure monitoring system for an inductive communication device according to claim (1), wherein the inductive communication line is an inductive antenna line. (3) A fault monitoring system for an inductive communication device according to claim (1), wherein the inductive communication line is a leaky coaxial cable.