JPH01219999A - Power line carrying control interface unit - Google Patents

Abstract

PURPOSE:To prevent an erroneous judgement caused by noise and to raise the reliability of a control system by judging that an apparatus is in an operating state, in case an interval of the time when a commercial AC load current exceeds a prescribed value has coincided with a period of a commercial power source. CONSTITUTION:By a current sensor 110, a commercial AC load current value is detected, and by a zero crossing detector 111, voltage zero crossing of a commercial power source is detected. By judging the coincidence of an interval of the time when a commercial AC load current value exceeds a prescribed value and a period of voltage zero crossing by a CPU 103, whether an apparatus 100 is operating or not is decided. A result of this decision is transferred to a hole controller through a MODEM 102, a coupler 101 and a power line 3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a control system in which a controller controls various devices connected to a power line via an interface unit by means of a conveyor using a power line, a dedicated cable, etc. This invention relates to a control interface unit.

[Conventional technology]

Home control systems or home security systems that have been developed in recent years use power lines, dedicated cables, etc. as data buses.

For example, FIG. 4 shows an example of a so-called home bus system, in which a home controller 1 is installed in the home, the home controller 1 uses a power line 3 as a data bus, and various devices 4 to 4 connected to the power line 3 are connected to the power line 3. 9 is centrally controlled on and off.

Further, the home controller 1 receives data outputs indicating the operating states of the various devices 4 to 9, and centrally displays and monitors the operating states.

Data such as control data and monitor data is transmitted and received between the home controller 1 and various devices 4 to 9.
Interface unit (IFU) 1 installed separately in 9
1 to 16.

In a home bus system, the controller must check whether the operation of the target device is correctly controlled according to the instructions, and periodically request the device to report the operating status of the device. However, if there is a change in the operating status of the device, the data is transmitted to the controller.

[Problem to be solved by the invention]

For the controller to know the operating status of various devices, if the device itself has a dedicated monitor signal terminal that notifies the outside of its operating status, the IFU can receive this signal and transmit it to the controller via the power line. ,there is no problem. However, since general equipment does not have a dedicated monitor signal terminal, the IFU generally measures the value of the current flowing through the equipment to detect its operating state.

By the way, in the latter case, the connected equipment includes equipment with low power consumption, such as a fluorescent lamp, and the current criterion for detecting the operating state must be set low. Therefore,
Even when the control equipment is not operating, noise from the power line often causes a current detection operation to be performed incorrectly, resulting in a malfunction in which the controller is notified.

An object of the present invention is to provide a highly reliable IF'U which is a general method for detecting the load current of equipment and detecting its operating state, but does not cause malfunctions such as noise.

[Means to solve the problem]

The interface unit of the present invention includes a current detecting means that detects a commercial AC load current value of a device and outputs an output when the current value exceeds a certain value, a commercial power supply cycle detecting means, and a starting point between each output by the current detecting means. This control system includes means for determining whether or not the time interval is equal to the period determined by the commercial power supply period detection means, and means for transmitting information regarding the operating state of the equipment to the controller based on the determination.

[Effect]

The commercial AC load current value of the equipment changes with a constant period of a sine wave. Therefore, the point in time when the current value exceeds a certain value also occurs in cycles M (periods of the commercial AC frequency). However, even if noise exceeding a certain current value is detected, the period of the noise pulse is random, so it can be immediately distinguished from a normal operating state.

Therefore, malfunctions will not occur even if the fixed current value to be determined is set low in accordance with low power consumption equipment.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit block diagram of an embodiment. The part surrounded by a dotted line in the figure is the IFU 200 of the embodiment. Equipment 10
0 becomes operational by inserting its outlet 100A into the outlet 109 of the IFU 200. IF
At U200, a signal separated from power line 3 by coupler 101 is input to modem 102. Also modem 102
The output from the power line 3 is outputted to the power line 3 via the coupler 101. The modem 102 is connected to the CPU 103. RAM104, RO
It exchanges data with the data processing unit consisting of M105. The machine number setting switch 106 and type setting switch 107, which are connected to the data bus DB via I/(]1) and I/(]2), are for specifying the device 100 that uses this rFU 200. be. I 10(3)
, I10(4), each part connected to the device 100
This is a part related to the present invention that controls and detects the operating state of the. A current sensor 110 serves as a current detection means to detect a commercial AC load current value, and a zero cross detector 111 serves as a commercial power supply cycle detection means to detect a voltage zero cross of the commercial power supply.

Next, a case in which the device 100 is operated under the control of the home controller 1 (see FIG. 4) will be explained step by step.

(a) The home controller 1 outputs a control data packet in the formant shown in FIG. 2 to the power line 3. Although a description of this format will be omitted, the control code includes the machine number of the SA double signal transmission source, the machine number of the DA double signal reception destination, and the OPC signal.

(b) If the DA signal included in the control data bucket is a numerical value set in the FU 200, the CPU 103 assumes that the data is addressed to its own station and takes in the data.

(c) If the data demodulated by the demodulator 102A of the modem 102 is input to the CPU 103 and the OPC signal data is ON control, the relay 112 is operated via the data bus DB and T/○ (4). Close contact 112A. This relay 112 is a latch type, and its contacts 112A do not open until an off signal is received.

(d) Since the contact 112A is closed and the power is connected to the device 100, if the device 100 is in an operating state (the power switch of the device is on), the current sensor 110 outputs an output when the load current value exceeds a certain value. . Since the current sensor 110 is designed to always output a constant value if the current is above a certain value, the square wave is generated at constant intervals t' as shown by waveform C in the signal waveform diagram of FIG. Occurs in

(E) On the other hand, the zero cross detector 111 outputs a pulse as shown in the waveform of FIG. 3 when the voltage of the commercial power supply of the power line 3 is zero. Therefore, this pulse interval is the period of waveform a of electric tA (commercial alternating current) (in this case, the period corresponding to 1/2 wavelength)
Equal to to. Note that the current sensor 110 detects only the amplitude value without considering the polarity. If the current sensor 110 detects only one polarity, it will be equal to every other pulse interval of the zero-crossing waveform.

(to) The former two signals (signals with waveforms C and b) are each I
/O (input to port PL and port P2 of 31, and input to CPU 103 via data bus DB.

(g) Within a certain period of time, the CPU 103 determines the period t0. t'. If they are determined to be the same, device 1
It is determined that modem 102.00 is in operation, and the determination signal is sent to modem 102. Combiner 101. It is transmitted to the home controller 1 via the power supply 3.

When the device is not operating or when external noise is detected by the current sensor 110, it can be determined that the device is not operating based on the above criteria. In the case of external noise, the pulse interval tI+t2 becomes random as shown in waveform d in FIG.

Through the above steps, the home controller l is connected to the device 100.
When a control command is issued to a device 100, it can be reliably confirmed whether or not the device 100 is controlled. The IFU 200 also allows the home controller 1 to check the operating status of the device 100.
The I/O (
This can be done by reading the signal from 31.

In this embodiment, the zero-crossing detector 111 was used to determine the commercial power supply cycle; however, it does not necessarily measure zero-crossing, and another method may be used, but it was adopted because it is relatively inexpensive and has good accuracy. be.

〔Effect of the invention〕

As explained above, the present invention provides a control system that uses power lines, etc., in which an interface unit provided between the power lines, etc. and equipment, as a means of knowing the operating state of the equipment, controls the commercial AC load current to exceed a certain value. If the time interval at which this constant value occurs matches the cycle of the commercial power supply, it is determined that the device is in an operating state, and a determination signal is sent to the controller. . Therefore, when the equipment is not in an operating state and noise is mixed into the power line, incorrect judgment can be prevented and a highly reliable control system can be constructed.

[Brief explanation of the drawing]

Fig. 1 is a circuit block diagram of an embodiment of the present invention, Fig. 2 is an example of a control data packet from a controller, Fig. 3 is a signal waveform diagram of the embodiment, and Fig. 4 is an overall diagram of the home control system. be. 1-home controller, 3--power line, 100
--- Equipment, 101-- Coupler, 102--
Modem, 103-CPU. 110--Current sensor, 111--Zero cross detector, 112--Relay,
1121--Contact, 200...IFU.

Claims (1)

[Scope of Claims] A control system in which a controller controls equipment connected to a power line via an interface unit using a conveyance means using a power line, dedicated cable, etc., wherein the interface unit controls the commercial AC load current of the equipment. a current detection means that detects a current value and outputs an output when the current value exceeds a certain value; a commercial power supply cycle detection means; and a time interval between the start points of each output by the current detection means is the same as the cycle of the commercial power supply cycle detection means. 1. An interface unit comprising: means for determining whether or not the operating state of the device is met; and means for transmitting information regarding the operating state of the device to a controller based on the determination.