JP2011023954A - Alarm mask circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit for masking alarm signals when broadcasting is in a pause. <P>SOLUTION: In the alarm mask circuit, when the alarm signal indicating failure of the broadcast wave signal of a first system and the alarm signal indicating the failure of the broadcast wave signal of a second system are input to a logic circuit 11, the logic circuit 11 outputs alarm mask signals to a mask unit 12 and a mask unit 13. When the alarm mask signal is input from the logic circuit 11 to the mask unit 12, the mask unit 12 masks a first alarm signal to be sent from In3 to Out3. Also, when the alarm mask signal is input from the logic circuit 11 to the mask unit 12, the mask unit 13 masks the alarm signal to be sent from In4 to Out4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an alarm mask circuit for masking an alarm signal so as not to be transmitted to an external device such as a remote controller when broadcasting is suspended.

  In a broadcast network, a microwave TTL (Transmitter to Transmitter Link) line is used for signal transmission between transmitting stations. In the TTL line, transmission using an IF transmission method in which an OFDM modulated wave is directly put on a microwave is performed.

  In broadcast wave relay, when the broadcast is stopped at night or the like, there is no input of the broadcast signal to the TTL transmitter / receiver, and an input abnormality is detected. When an input abnormality is detected, the TTL transceiver generates an alarm signal and sends it to a remote controller at a remote location.

  In practice, however, the suspension of broadcasting is not an input abnormality. For this reason, if an alarm is sent at the time of broadcasting suspension, there is a possibility that the remote controller will detect an input abnormality although it is not actually abnormal. In order to prevent erroneous detection of an input abnormality, it is necessary to accurately detect a case where there is no input signal for the suspension of broadcasting, and to control not to transmit an alarm to the remote controller when the broadcasting is suspended.

  As a technique for detecting broadcast suspension, for example, in the broadcast wave relay device described in Patent Document 1, in order to determine whether the signal input power is reduced due to fading, multipath, or broadcast suspension, Monitoring is performed regularly.

Japanese Patent Laying-Open No. 2008-78806 (paragraph 0028, FIG. 2)

  In the broadcast wave repeater described in Patent Document 1, the received power is monitored periodically, and when the state where the input power is lower than the preset value stored in advance is continued for a predetermined number of times or more, it is determined that the broadcast is suspended. The output is controlled to stop. However, periodic monitoring of received power complicates the processing, and the processing capability of the relay apparatus may be wasted.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an alarm mask circuit that detects broadcast suspension and masks an alarm signal when the broadcast is suspended.

  An alarm mask circuit according to an embodiment of the present invention includes a first alarm signal indicating a level abnormality of a first wave system broadcast wave signal and a second alarm signal indicating a level error of a second wave wave signal. When input, a logic circuit for outputting an alarm mask signal, a first mask means for masking the first alarm signal when an alarm mask signal is input from the logic circuit, and an alarm mask signal input from the logic circuit Then, a second mask means for masking the second alarm signal is provided.

  According to the alarm mask circuit according to the embodiment of the present invention, when the first and second alarm signals are input to the logic circuit, the logic circuit outputs the alarm mask signal. When the alarm mask signal is output from the logic circuit, the alarm signal is masked. For this reason, an alarm can be masked at the time of broadcasting suspension.

The figure which shows the structure of the alarm mask circuit which concerns on one Embodiment of this invention. The timing chart which shows the state of signal transmission when an alarm signal is input into one system | strain. The timing chart which shows the state of signal transmission when an alarm signal is input into both systems. The figure which shows the system configuration at the time of applying an alarm mask circuit to a TTL transmitter. The figure which shows the system configuration | structure at the time of applying an alarm mask circuit to a TTL receiver.

  Embodiments of an alarm mask circuit according to the present invention will be described below with reference to the drawings.

  The alarm mask circuit described below is used in a broadcasting apparatus such as a TTL transmitting / receiving apparatus that performs signal transmission through a TTL line, for example. In the TTL line, the broadcast wave is transmitted through two systems of the first system and the second system, and even if a failure occurs in one system in the broadcast apparatus, the transmission of the broadcast wave is continued in the other system. When the broadcast is suspended, the signal level of the broadcast wave decreases in almost the same timing in both the first system and the second system. For this reason, in the embodiment described below, when the signal level decreases in both systems, the alarm is masked and not transmitted to the remote controller. The remote controller is a device that monitors the operation of the broadcasting device, and may be provided in a performance place (studio) that is remote from the broadcasting device.

  FIG. 1 is a circuit diagram showing a configuration of an alarm mask circuit according to an embodiment of the present invention. As will be described later with reference to FIGS. 4 and 5, the alarm mask circuit 10 is used in a TTL transmitter or a TTL receiver.

  The alarm mask circuit 10 includes input terminals In1 to In5, output terminals Out1 to Out4, a logic circuit 11, and mask units (MASK) 12 and 13.

  The alarm signal of the first system representing the level decrease of the broadcast wave signal of the first system is input to the input terminal In1 from a device provided in the previous stage of the alarm mask circuit 10. Similarly, a second-system alarm signal indicating a decrease in the level of the second-system broadcast wave signal is input to the input terminal In2 from a device provided in the preceding stage of the alarm mask circuit 10.

  The alarm signal input to the input terminal In1 is sent to the output terminal Out1 and the logic circuit 11. The alarm signal input to the input terminal In2 is sent to the output terminal Out2 and the logic circuit 11.

  The logic circuit 11 is an AND circuit that operates according to input signals from the input terminal In1 and the input terminal In2. When an alarm signal is input from both the input terminal In1 and the input terminal In2, the logic circuit 11 outputs an alarm mask signal to the mask units 12 and 13.

  A first system alarm signal from the TTL transmitter or TTL receiver to the remote controller is input to the input terminal In3. The second terminal alarm signal from the TTL transmitter or TTL receiver to the remote controller is input to the input terminal In4. As will be described later with reference to FIGS. 4 and 5, the alarm signal input to the input terminal In3 may be the same signal as the alarm signal input to the input terminal In1, or the alarm signal input to the input terminal In4. The signal may be the same signal as the alarm signal input to the input terminal In2.

  The alarm signal input to the input terminal In3 is sent to the mask unit 12. The alarm signal input to the input terminal In4 is sent to the mask unit 13.

  The mask unit 12 is provided between the input terminal In3 and the output terminal Out3. When no alarm mask signal is input from the logic circuit 11, the mask unit 12 sends the first system alarm signal input from the input terminal In3 to the output terminal Out3. When there is an alarm mask signal input from the logic circuit 11, the mask unit 12 masks the first system alarm signal and does not send it to the output terminal Out3.

  The mask unit 13 is provided between the input terminal In4 and the output terminal Out4. When no alarm mask signal is input from the logic circuit 11, the mask unit 13 sends the second-system alarm signal input from the input terminal In4 to the output terminal Out4. When the alarm mask signal is input from the logic circuit 11, the mask unit 13 masks the second system alarm signal and does not send it to the output terminal Out4.

  A reset signal for resetting the status display of the alarm mask circuit 10 is input to the input terminal In5.

  The alarm signal of the first system output from the output terminal Out1 is output to a device provided in the subsequent stage of the alarm mask circuit 10. Similarly, the second-system alarm signal output from the output terminal Out2 is output to a device provided in the subsequent stage of the alarm mask circuit 10. As a result, an alarm signal indicating a decrease in the level of the broadcast wave is transmitted to the subsequent apparatus.

  From the output terminal Out3, an alarm signal of the first system is output to the remote controller. Similarly, the second system alarm signal is output from the output terminal Out4 to the remote controller. The remote controller can monitor the signal level of the broadcast wave of the first system or the second system with reference to the alarm signal of the first system or the second system. When an abnormality occurs in the signal level, the abnormality information is output to the output unit of the remote controller, and the abnormality of the signal level of the broadcast wave can be confirmed in the studio.

  When there is an alarm mask signal input from the logic circuit 11, the mask unit 12 masks the first system alarm signal, so that no alarm signal is output from the output terminal Out3 to the remote controller. Similarly, when an alarm mask signal is input from the logic circuit 11, the mask unit 13 masks the second system alarm signal, so that no alarm signal is output from the output terminal Out4 to the remote controller. The reason why the alarm mask signal is input from the logic circuit 11 to the mask units 12 and 13 is that the first system alarm signal is input to the input terminal In1, and at the same time the second system alarm signal is input to the input terminal In2. It is. That is, an alarm mask signal is output from the logic circuit 11 to the mask units 12 and 13 when both of the first system broadcast wave signal level decrease and the second system broadcast wave signal level decrease occur. For this reason, when both the first-system broadcast wave level drop and the second-system broadcast wave level drop occur, the abnormality of the broadcast wave signal level is considered to have occurred due to the suspension of the broadcast. The alarm signals of the second both systems are not transmitted to the remote controller.

  The DC-DC converter 14 is a switching type converter that converts a DC voltage into another DC voltage. The converter 14 converts a predetermined voltage (for example, 48 volts) supplied through the switch S1 and the switch S2 and provides a voltage for operating the first system and the second system of the alarm mask circuit 10.

  FIG. 2 is a timing chart showing a signal transmission state when an alarm signal is input to one system.

  In FIG. 2, an alarm signal indicating a decrease in the level of the first system broadcast wave signal is input from the input terminal In1, and the first system alarm signal is also input from the input terminal In3. On the other hand, no alarm signal is input to the input terminals In2 and In4 of the second system. That is, a signal level abnormality has occurred in the first-system broadcast wave, but no abnormality has occurred in the second-system broadcast wave. That is, in the example of FIG. 2, it can be considered that the abnormality in the signal level of the first system broadcast wave is not caused by the suspension of the broadcast, but is caused by the abnormality of the preceding apparatus. In this case, the alarm signal is not masked by the mask unit 12 and is output from the output terminal Out3 to the remote controller.

  In FIG. 2, if the second system alarm signal is not detected even after a predetermined time (for example, 5 seconds) after the first system alarm signal is detected, the first system alarm signal is output to the output terminal Out3. It is output from. If a relative delay occurs in the transmission of the broadcast wave in the first system and the second system, a temporal error occurs until the alarm signal of both systems is detected even if the broadcast is stopped. When the alarm signal of one system is input to the logic circuit 11 and the alarm signal of the other system is input to the logic circuit 11 within a predetermined time error after the alarm signal of one system is input to the logic circuit 11, Alarm masking is performed as occurring. Conversely, if the alarm signal of the other system is not input to the logic circuit 11 within the time error after the alarm signal of one system is input to the logic circuit 11, the alarm mask is not performed.

  FIG. 3 is a timing chart showing the state of signal transmission when alarm signals are input to both systems.

  In FIG. 3, an alarm signal indicating a decrease in the level of the first system broadcast wave is input from the input terminal In1, and then the second system alarm signal is also input from the input terminal In2 within a predetermined time (5 seconds). Has been. That is, after an abnormality in the signal level of the first system broadcast wave occurs, an abnormality also occurs in the second system broadcast wave within a predetermined time. That is, in the example of FIG. 3, it is assumed that an abnormality has occurred in the signal level of the broadcast wave in both systems due to the suspension of broadcasting. In this case, the alarm signal of the first system is masked by the mask unit 12, and is not output from the output terminal Out3 to the remote controller. Similarly, the second system alarm signal is also masked by the mask unit 13 and is not output from the output terminal Out4.

  In FIG. 3, the alarm mask is not received after a predetermined time (in this case, 5 seconds) after the first system alarm signal is not input to the input terminal In1 and the second system alarm signal is not input to the input terminal In2. Is released. Even if the broadcast suspension is canceled and the transmission of the broadcast wave is performed, the first system alarm signal input to the alarm mask circuit 10 due to the delay in the transmission of the broadcast wave in the first system and the second system There is a possibility that a time error occurs at the timing when the alarm signal of the second system disappears. For example, if the alarm mask state is released immediately after the first system alarm signal is not input, the second system alarm signal may be transmitted to the remote controller when the detection of the second system broadcast wave is delayed. Absent. For this reason, a margin of 5 seconds is given here before releasing the alarm mask state.

  FIG. 4 shows a system configuration when the above-described alarm mask circuit 10 is applied to the TTL transmitter 30.

  The TTL transmitter 30 is a device that transmits the signal transmitted from the pre-stage device 20 from the antenna 34 using microwaves. The upstream device 20 is, for example, a broadcast wave receiving device, and sends the IF signal sent from the transmitting station to the TTL transmitting device 30.

  The TTL transmitter 30 includes a first system transmission unit (TX) 31, a second system transmission unit (TX) 32, a switch 33, and an antenna 34. The signal sent from the pre-stage device 20 is converted into an RF (Radio Frequency) signal by TX 31 and 32. One of the RF signals is selected by the switch 33 and emitted from the antenna 34.

  For example, when the pre-stage device 20 such as a broadcast wave receiver detects a decrease in the level of the first system broadcast wave, the first system alarm signal is input from the pre-stage device 20 to the input terminal In1. Similarly, when the pre-stage device 20 detects a decrease in the level of the second system broadcast wave, the second-system alarm signal is input from the pre-stage device 20 to the input terminal In2.

  The alarm signal input to the input terminal In1 is sent to the output terminal Out1 and the logic circuit 11. The alarm signal input to the input terminal In2 is sent to the output terminal Out2 and the logic circuit 11. The alarm signal of the first system output from the output terminal Out1 is input to the TTL transmitter 30. The second-system alarm signal output from the output terminal Out2 is also input to the TTL transmitter 30.

  When an alarm signal is input from both the input terminal In1 and the input terminal In2, an alarm mask signal is output from the logic circuit 11 to the mask units 12 and 13.

  The alarm signal of the first system is input from the TTL transmitter 30 to the input terminal In3. In the present embodiment, an alarm signal of the first system that is input from the input terminal In1 and output from the output terminal Out1 is input to the input terminal In3 via the TTL transmitter 30. Similarly, the second-system alarm signal is input from the TTL transmitter 30 to the input terminal In4. In the present embodiment, an alarm signal of the second system that is input from the input terminal In2 and output from the output terminal Out2 is input to the input terminal In4 via the TTL transmitter 30.

  The alarm signal input to the input terminal In3 is sent to the mask unit 12. The alarm signal input to the input terminal In4 is sent to the mask unit 13.

  When no alarm mask signal is input from the logic circuit 11, the mask unit 12 sends the first system alarm signal input from the input terminal In3 to the output terminal Out3. When there is an alarm mask signal input from the logic circuit 11, the mask unit 12 masks the first system alarm signal and does not send it to the output terminal Out3.

  When no alarm mask signal is input from the logic circuit 11, the mask unit 13 sends the second-system alarm signal input from the input terminal In4 to the output terminal Out4. When an alarm mask signal is input from the logic circuit 11, the mask unit 13 masks the second system alarm signal and does not send it to the output terminal Out4.

  From the output terminal Out3, an alarm signal of the first system is output to the remote controller 40. Similarly, the second system alarm signal is output to the remote controller 40 from the output terminal Out4. The remote controller 40 monitors the signal level of the broadcast wave of the first system or the second system with reference to the alarm signal of the first system or the second system. When an abnormality occurs in the signal level, abnormality information is output to the output unit of the remote controller 40, and an abnormality in the signal level of the broadcast wave can be confirmed in the studio.

  When there is an alarm mask signal input from the logic circuit 11, the mask unit 12 masks the first system alarm signal, so that no alarm signal is output from the output terminal Out3 to the remote controller 40. Similarly, when an alarm mask signal is input from the logic circuit 11, the mask unit 13 masks the second system alarm signal, so that no alarm signal is output from the output terminal Out 4 to the remote controller 40.

  That is, when the pre-stage device 20 detects the first system and second system alarm signals due to the first system broadcast wave level decrease and the second system broadcast wave level decrease and inputs them to the alarm mask circuit 10, An abnormality in the signal level of the broadcast wave is caused by the suspension of the broadcast, and the alarm signals of both the first and second systems are not transmitted to the remote controller 40.

  FIG. 5 shows a system configuration when the above-described alarm mask circuit 10 is applied to the TTL receiver 60.

  The TTL receiving device 60 is a device that transmits a broadcast wave received by the antenna 61 to the subsequent device 50. The succeeding apparatus 50 is, for example, a relay station transmitter, and transmits the IF signal or TS signal received by the TTL receiving apparatus 60 by broadcast waves.

  The TTL receiver 60 includes an antenna 61, a distributor 62, a first system reception unit (RX) 63, and a second system reception unit (RX) 64. The RF signal received by the antenna 61 is distributed to RX 63 and RX 64 by the distributor 62. RX 63 and RX 64 convert the received signal into an IF signal or a TS signal and output the converted signal to the subsequent apparatus 50.

  When the RX 63 detects a decrease in the signal level of the first system broadcast wave, the first system alarm signal is input to the input terminal In1. Similarly, when the RX 64 detects a decrease in the signal level of the second system broadcast wave, the second system alarm signal is input to the input terminal In2.

  The alarm signal input to the input terminal In1 is sent to the output terminal Out1 and the logic circuit 11. The alarm signal input to the input terminal In2 is sent to the output terminal Out2 and the logic circuit 11. The alarm signal of the first system is output from the output terminal Out1 and is input to the subsequent apparatus 50. The second-system alarm signal is output from the output terminal Out2 and is input to the subsequent apparatus 50. Thereby, a decrease in the signal level of the broadcast wave can be transmitted to the subsequent apparatus 50.

  When an alarm signal is input from both the input terminal In1 and the input terminal In2, an alarm mask signal is output from the logic circuit 11 to the mask units 12 and 13.

  The alarm signal of the first system is also input from the RX 63 to the input terminal In3. Similarly, the alarm signal of the second system is input from the RX 64 to the input terminal In4. The alarm signal input to the input terminal In3 is sent to the mask unit 12. The alarm signal input to the input terminal In4 is sent to the mask unit 13.

  When no alarm mask signal is input from the logic circuit 11, the mask unit 12 sends the first system alarm signal input from the input terminal In3 to the output terminal Out3. When there is an alarm mask signal input from the logic circuit 11, the mask unit 12 masks the first system alarm signal and does not send it to the output terminal Out3.

  When no alarm mask signal is input from the logic circuit 11, the mask unit 13 sends the second-system alarm signal input from the input terminal In4 to the output terminal Out4. When an alarm mask signal is input from the logic circuit 11, the mask unit 13 masks the second system alarm signal and does not send it to the output terminal Out4.

  When there is no alarm mask signal input from the logic circuit 11 to the mask unit 12, the first system alarm signal is output from the output terminal Out3 to the remote controller 40. Similarly, when no alarm mask signal is input from the logic circuit 11 to the mask unit 13, an alarm signal of the second system is output from the output terminal Out 4 to the remote controller 40. The remote controller 40 monitors the signal level of the broadcast wave of the first system or the second system with reference to the alarm signal of the first system or the second system.

  When there is an alarm mask signal input from the logic circuit 11, the mask unit 12 masks the first system alarm signal, so that no alarm signal is output from the output terminal Out3 to the remote controller 40. Similarly, when an alarm mask signal is input from the logic circuit 11, the mask unit 13 masks the second system alarm signal, so that no alarm signal is output from the output terminal Out 4 to the remote controller 40.

  That is, the RX 63 detects a level drop of the first system broadcast wave and inputs an alarm signal to the alarm mask circuit 10, and the RX 64 detects a level drop of the second system broadcast wave and sends the alarm signal to the alarm mask circuit 10. When the signal is input to, an abnormality in the signal level of the broadcast wave is caused by the suspension of the broadcast, and the alarm signals of both the first and second systems are not transmitted to the remote controller 40.

  As described above, according to the alarm mask circuit according to the present embodiment, when the input signal levels of both the first and second systems are abnormal, the alarm signal is masked and is not transmitted to the remote controller. This prevents the alarm signal from being transmitted to the remote controller when broadcasting is suspended.

  Further, when the alarm signal of the other system is not input within a predetermined time after the alarm signal of one system is input, the alarm mask is not performed. For this reason, even when a relative delay occurs in the transmission of signals between both systems, it is possible to accurately detect the case of broadcasting suspension.

  Further, the alarm mask is continued for a predetermined time after the alarm signal of one system is not input while the alarm mask is being performed. For this reason, when a broadcast wave is transmitted after the broadcast suspension is canceled, even if a relative delay occurs in the transmission of the broadcast wave between both systems, the alarm of the delayed system is transmitted to the subsequent stage. Can be prevented.

  In the above-described embodiment, the case where the alarm mask circuit is used in a broadcast wave transmitting / receiving device has been described. However, the above-described alarm mask circuit is not limited to a broadcast system, and can be used in various devices in order not to transmit an alarm to a subsequent stage.

  As shown in FIGS. 4 and 5, the alarm mask circuit 10 may be connected to the TTL transmitter 30 and the TTL receiver 60, or may be provided in the TTL transmitter 30 and the TTL receiver 60. Good.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention when it is practiced. Further, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in one embodiment or the constituent elements shown in some embodiments are combined, they are described in the column of the problem to be solved by the invention. In the case where the problems described above can be solved and the effects described in the “Effects of the Invention” can be obtained, a configuration in which these constituent requirements are deleted or combined can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 10 ... Alarm mask circuit, 11 ... Logic circuit, 12, 13 ... Mask unit, 14 ... DC-DC converter, In1-In5 ... Input terminal, Out1-Out4 ... Output terminal.

Claims (6)

A logic circuit that outputs an alarm mask signal when a first alarm signal indicating a level abnormality of a first wave of broadcast wave signals and a second alarm signal indicating a level error of a second wave of broadcast waves are input; ,
First alarm means for masking the first alarm signal when an alarm mask signal is input from the logic circuit;
Second alarm means for masking the second alarm signal when an alarm mask signal is input from the logic circuit;
An alarm mask circuit comprising:   The logic circuit outputs the alarm mask signal when the other alarm signal is input within a predetermined time after one of the first and second alarm signals is input to the logic circuit. The alarm mask circuit according to claim 1.   If one of the first and second alarm signals is not input to the logic circuit and the other alarm signal is also not input after a predetermined time, the logic circuit stops outputting the alarm mask signal. The alarm mask circuit according to claim 1.   The alarm mask circuit according to claim 1, wherein the broadcasting device is a TTL (Transmitter to Transmitter Link) transmission device.   The alarm mask circuit according to claim 1, wherein the broadcasting device is a TTL receiving device.   The first alarm signal output from the third output terminal and the second alarm signal output from the fourth output terminal are sent to a remote controller provided far away from the broadcasting device. The alarm mask circuit according to claim 1.

Images