JPH04242345A - Rolling system - Google Patents

Abstract

PURPOSE:To discriminate the presence of a contact signal correctly from a peripheral equipment being monitored. CONSTITUTION:A means to send a criterion as to a contact signal 26 to a terminal equipment 1 is provided in a center station. A CPU section 22 recognizes the criterion based on polling from the center station and the terminal equipment 1 discriminates the presence of the contact signal 26 from a peripheral equipment 2 according to the criterion.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD The present invention relates to a polling system, and more particularly to a polling system in a CATV network.

0002

2. Description of the Related Art Generally, a CATV network is composed of a center station, a plurality of terminal devices, and peripheral devices connected to these terminal devices.

[0003] Conventionally, a center station in a CATV network polls each terminal device through a bidirectional CATV transmission path, and receives contact signals output from peripheral devices according to their operating states via the terminals. and monitored the status of peripheral devices.

That is, in the conventional polling system described above, each terminal device includes a CPU therein, constantly detects the presence or absence of a contact signal to the terminal device, and sends out the result in response to polling from the center station. It was. In this terminal, if a contact signal is continuously detected for a certain period of time or more, it is determined that there is a contact, but this determination reference time is fixed. Therefore, there is a drawback that it may not be possible to correctly determine the presence or absence of a contact signal due to differences in the characteristics (output duration time of the contact signal) of various monitoring devices connected to the terminal.

[0005]

OBJECTS OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and its purpose is to provide a polling system that can correctly determine the presence or absence of a contact signal from a monitored device. be.

[0006]

SUMMARY OF THE INVENTION A polling system according to the present invention includes a plurality of peripheral devices, a plurality of terminal devices connected to the plurality of peripheral devices for monitoring connection partners, and a polling system for communicating with the plurality of terminal devices. and a central device that monitors the plurality of peripheral devices, the polling system being provided in the central device and determining for each of the terminal devices whether a connected peripheral device is normal or abnormal. and a monitoring means provided in each of the plurality of terminal devices to monitor the peripheral device based on the judgment conditions sent from the condition sending means. Features.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the internal configuration of one terminal device in a CATV network employing a polling system according to the present invention. In the figure, a terminal device 1 is connected to a center station (not shown), and a plurality of devices having the same configuration as this terminal device 1 are connected to the center station.
It constitutes an ATV network. Additionally, peripheral devices are connected to each terminal device, and peripheral devices 2 and 2 are also connected to each terminal device.
is connected. Examples of peripheral devices include optical transmission terminal equipment, TV switchers, pilot signal generators, and home terminal control devices.

The terminal device 1 determines the operating state of the peripheral device 2 based on the state of the contact signal 26 from the peripheral device 2. The terminal device 1 and the peripheral device 2 have a connection relationship as shown in FIG. 2 regarding the contact signal 26. That is, referring to FIG. 2, there is a relay 29 in the peripheral device 2;
When it detects an abnormality in its own operation, it closes this relay 29 and creates a current loop. The signal generated by this relay 29 is the contact signal 26, and the terminal device 1
peripheral device 2 by detecting the state in which a loop is configured.
It is possible to recognize abnormal conditions.

Returning to FIG. 1, the terminal device 1 receives the contact signal 26
an interface unit 25 that accepts
, a demodulator 20 that sends out a received signal 21, and a response signal 2.
a modulation unit 24 that modulates the address switch 40;
It is configured to include a CPU section 22 that controls each section. Note that 10 is a transmission path.

The terminal device 1 responds to the operating status of peripheral devices by polling from the center station, but each terminal device needs to have a unique polling address, so when installing the terminal device, the address switch 40 Set the polling address to . This setting value is read and recognized by the CPU section 22 inside the terminal device.

[0012] In the system of the present embodiment including the terminal device having such a configuration, control is performed to set the time for determining the presence or absence of contact based on a telegram notification sent from a center station (not shown).

[0013] In order to notify a certain terminal of the conditions for determining the presence or absence of contact input from the center station, it is necessary to use the terminal's unique address and the determination time for the presence or absence of contact (continuous contact closure detection time to determine that there is a contact, and determination that there is no contact). continuous contact opening time)
and send it in the downstream direction. This message is CAT
The received signal 21 passes through the V transmission path 10 and is input to the demodulator 20 via the directional coupler 30 inside each terminal, and the received signal 21 after demodulation is input to the CPU unit 22 .

When the CPU unit 22 decodes the received message, it recognizes the continuous contact closed detection time (t1) for determining that there is a contact from the outside, and the continuous contact open time (t2) for determining that there is no contact. . After setting these determination conditions, the center station polls each terminal device in turn and collects response signals 26 indicating the contact input state from the terminal devices.

Here, as shown in FIG. 3, there are two operating modes of the peripheral device, a and b, and the output timing of the contact signal may be different between the two modes. In such a case, if it is desired to detect only the state of operation mode b, Tb in the figure may be set to the above-mentioned t1. In this way, the terminal device can detect only the state of operation mode b without detecting the state of operation mode a. Conversely, Ta is the above t
If it is set to 1, only the case of operation mode a can be detected.

In other words, the determination conditions are set from the center station depending on the operating mode.

In the terminal device, when the contact signal 26 becomes closed (contact present), the contact signal interface section 25 detects this state and generates an interrupt signal 27 to the CPU section 22 . After the occurrence of the interrupt, the CPU section 22 outputs a contact state signal 28 to know whether there is a current contact signal after a time t1.
is read from the contact signal interface section 25. At this time, the contact signal interface section 25 outputs the current contact input state as it is to the CPU section 22 as a contact state signal 28. As a result, if there is a contact, the CPU section 22 determines that there is a contact.

[0018] Also, the contact signal 2 that has been input until now
6 is open, the contact signal interface section 25
An interrupt signal 27 is generated for the unit 22. CPU section 2
2 reads the contact status signal 28 from the contact signal interface unit 25 after a time t2 after the occurrence of the interrupt in order to know whether there is a current contact signal. At this time, if it is read that there is no contact signal, it is determined that there is no contact.

The determination of the presence or absence of these contact signals is independently performed by the CPU section 22 in the terminal device, independent of the operation of receiving the polling message from the center station, and when polled from the center station, the CPU section 22 transmits the determination result as a response signal to the center station. Further, in response to polling from the center station, the CPU unit 22 responds with information about the presence or absence of contact only to the polling message that matches its own address.

[0020] The CPU section 22 generates a response signal 23 and outputs it to the modulation section 24. The modulated signal is sent to the directional coupler 3
0, and is sent in the upstream direction of the CATV transmission line 10. In other words, a monitored device that outputs a contact signal to a terminal device may have different time and timing for outputting a contact signal indicating the operating status, but according to this system, the terminal device side It is possible to perform contact detection and to monitor peripheral devices in detail.

[0021] As the judgment conditions, in addition to the above-mentioned judgment time, various judgment conditions can be set from the center station.

[0022]

Effects of the Invention As explained above, the present invention allows the center station to arbitrarily specify conditions for determining the presence or absence of contact signals for each terminal device, and to adjust the conditions according to the contact signal output characteristics of the monitored equipment. By configuring a system that has the following features, monitoring functions can be improved.

[Brief explanation of the drawing]

[Figure 1] C adopting the polling system according to the present invention
FIG. 2 is a block diagram showing the internal configuration of a terminal device in an ATV network.

FIG. 2 is a block diagram showing the connection relationship between a terminal device and peripheral devices.

FIG. 3 is a waveform diagram of contact signals in each operation mode of the peripheral device.

[Explanation of symbols]

1 Terminal device 2 Peripheral equipment 22 CPU section 30 Directional coupler 40 Address switch

Claims (1)

[Claims] 1. A plurality of peripheral devices, a plurality of terminal devices connected to the plurality of peripheral devices and monitoring a connection partner, and communicating with the plurality of terminal devices by a polling method,
and a central device that monitors the plurality of peripheral devices, the polling system being provided in the central device and configured to determine for each of the terminal devices whether a connected peripheral device is normal or abnormal. The apparatus is characterized by comprising a condition sending means for sending out a judgment condition, and a monitoring means provided in each of the plurality of terminal devices and monitoring the peripheral device based on the judgment condition sent from the condition sending means. polling system.