Communications: electrical – Continuously variable indicating – With meter reading
Patent
1984-03-22
1985-12-10
Yusko, Donald J.
Communications: electrical
Continuously variable indicating
With meter reading
34082563, 34087024, H04Q 900
Patent
active
045583161
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a system for remote control of a plurality of electrical devices, the system having a master control station which governs the operation of a plurality of receiver stations which in turn are coupled to control and/or monitor electrical devices. The electrical devices could comprise any device that may be controlled or monitored by electrical signals. For instance, the electrical devices could comprise air conditioning controls, lighting switches, safety devices, displays, burglar alarms or the like.
U.S. Pat. No. 4,227,181 to Brittain discloses a time division multiplex communication system whereby the sync signal is voltage amplitude modulated, command and tell back signals are pulse width modulated and each time slot is assigned as either a command or tell back time slot.
U.S. Pat. No. 3,905,008 to Hagemann discloses an electronic signalling system from a consul station to a plurality of sensing units whereby voltage polarity and duration are used for signalling. The position of the sensing unit determines its address.
Other patents of interests are Australian Pat. No. 498,812 and Specification No. 22657/77 and U.K. Pat. No. 2,041,592A.
According to the present invention there is provided an electrical control system comprising a master station and a plurality of receiver stations connected thereto by a bus, said master station including generating means for generating control signals which are applied to said bus and to which said receiver stations are responsive, said control signals comprising a repetitive series of signal frames each frame including a reset pulse and a plurality of other pulses, said master station including control means which causes selectable alteration of a characteristic of said other pulses and wherein each of said receiver stations is addressed following receipt of a predetermined number of said other pulses, said receivers being responsive to said selectable characteristic of the other pulses whereby information is transmitted to addressed receiver stations in accordance with operation of said control means. Said receiver station when addressed also varies the bus impedance in accordance with its status and input.
In the preferred arrangement each signal frame commences with a reset pulse which is then followed by a predetermined or varying number of said other pulses which are used both for addressing the various receivers and for transmitting information to the various receivers.
Preferably further, each receiver station has at least one input, one output and three electrical impedances which are coupled to or not coupled to the bus line in accordance with the conditions of the output status, the input and receiver status at that receiver during the signalling period which occurs following addressing of that receiver. The master station includes a monitor coupled to the bus line and being operable to determine the impedance coupled to the bus line and assign logical value to the output status, input and status of that receiver responsive to that address, in accordance with the impedance coupled to the bus line. In the preferred arrangement, the three electrical impedances are resistances of value R for the receiver status, R/2 for the input and R/4 for output status.
In the preferred arrangement the master station transmits command output information to the selected remote receiver by varying the duration of the period to the next address pulse. In the alternative arrangement, the master station transmits command output information to the selected remote receiver by varying the number of zero pulses compared to the reset and address pulses which are at a non zero datum, during the period before the next address pulse.
The invention will now be further described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic representation of a system in accordance with the invention;
FIG. 2 is a block diagram of the master station;
FIG. 3 illustrates various signal waveforms useful in understanding the operation of the system;
FIG. 4 i
REFERENCES:
patent: 3440607 (1969-04-01), Abramson
patent: 3611361 (1971-10-01), Gallichotte
patent: 3905008 (1975-09-01), Hageman
patent: 3991413 (1976-11-01), Berger
patent: 4077030 (1978-02-01), Helava
patent: 4131882 (1978-12-01), Hollabaugh et al.
patent: 4196417 (1980-04-01), Fasching et al.
patent: 4227181 (1980-10-01), Brittain
patent: 4311986 (1982-01-01), Yee
patent: 4327441 (1982-04-01), Bradshaw
patent: 4359721 (1982-11-01), Galvin et al.
patent: 4394655 (1983-07-01), Wynne et al.
patent: 4451826 (1984-05-01), Fasching
patent: 4468664 (1984-08-01), Galvin
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