Remote control system for selectively activating and inactivating equipment
First Claim
1. Remote control system for selectively controlling switching on and switching off of electrical circuits by a transmitter at a location distant from the locations of a plurality of receivers each associated with an electric circuit which is to be switched on and off, said transmitter being equipped to broadcast to said receivers, and said receivers being equipped to receive control messages each consisting of binary digital signals and containing a control command and an address for selecting at least one of said receivers for response to said control command, and further comprising:
- means at said transmitter for incorporating in each control message eight data bits comprising seven addsress bits (D1-D7) and one control bit (D0) and seven check bits (C1-C7), said seven check bits being derived from said eight data bits by a Nordstrom-Robinson code utilizing said control bit non-cyclically in coding while said address bits are used cyclically, whereby all said check bits are inverted for transmission with a predetermined sign of said control bit, and for transmitting said check bits one immediately after another and said control bit immediately after said check bits, andmeans at each of said receivers including three registers, each for comparing incoming data bits with sets of data bits respectively designating three different addresses to which the receiver is to respond, one for individual response, one for response in a group composed of less than all said receivers and one for response in the group composed of all said receivers, and for also comparing received check bits with check bits relating to the addresses served by the register, said receivers also containing means for determining the number of bit identities in comparisons of a set of seven check bits and for determining the number of bit identities in comparison of a set of seven address bits, and for thereby determining whether said receiver is selected for response and which of two opposite possible commands is to be performed.
1 Assignment
0 Petitions
Accused Products
Abstract
Sixteen bit messages for selectively controlling receivers either to switch on an apparatus or to switch that apparatus off are transmitted on a format in which sixteen zeros are first transmitted, then a Willard sequence, then a control command, and then sixteen ones. The control command contains, in order of transmission, seven check bits, a control bit, seven address bits and a parity bit. The check bits are obtained by Nordstrom-Robinson coding from the eight data bits which consist of the seven address bits and a control bit, with cyclical rotation of the address bits but non-cyclical treatment of the control bit for deriving the seven check bits, with the result that, because the check bits and the control bit are received first, only three eight bit registers, each used twice first with the check bits as content and then with the address bits and the parity bit as content, are necessary for decoding at the receivers. The check bit comparison detects whether an on command or an off command is still possible and in one of those cases, treats the check bits as reversed in accord with the Nordstrom-Robinson coding, by the sign of the control bit.
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Citations
8 Claims
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1. Remote control system for selectively controlling switching on and switching off of electrical circuits by a transmitter at a location distant from the locations of a plurality of receivers each associated with an electric circuit which is to be switched on and off, said transmitter being equipped to broadcast to said receivers, and said receivers being equipped to receive control messages each consisting of binary digital signals and containing a control command and an address for selecting at least one of said receivers for response to said control command, and further comprising:
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means at said transmitter for incorporating in each control message eight data bits comprising seven addsress bits (D1-D7) and one control bit (D0) and seven check bits (C1-C7), said seven check bits being derived from said eight data bits by a Nordstrom-Robinson code utilizing said control bit non-cyclically in coding while said address bits are used cyclically, whereby all said check bits are inverted for transmission with a predetermined sign of said control bit, and for transmitting said check bits one immediately after another and said control bit immediately after said check bits, and means at each of said receivers including three registers, each for comparing incoming data bits with sets of data bits respectively designating three different addresses to which the receiver is to respond, one for individual response, one for response in a group composed of less than all said receivers and one for response in the group composed of all said receivers, and for also comparing received check bits with check bits relating to the addresses served by the register, said receivers also containing means for determining the number of bit identities in comparisons of a set of seven check bits and for determining the number of bit identities in comparison of a set of seven address bits, and for thereby determining whether said receiver is selected for response and which of two opposite possible commands is to be performed. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Method of remotely controlling switching on and off of electrical circuits respectively connected to receivers at a plurality of locations from a transmitter at a location distant from the location of said receivers, comprising the steps of:
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producing transmissions at said transmitter, each including a message containding eight data bits comprising seven address bits and one control bit and also seven check bits, including the substep of deriving said seven check bits from said eight data bits by a Nordstrom-Robinson code utilizing said control bit non-cyclically in coding said check bits while said address bits are used cyclically in coding said check bits, the transmitting being performed in a manner transmitting said check bits one immediately after another and said control bit immediately after said check bits; receiving said messages at each of said receivers; comparing the sequence of eight bits made up of said check bits and said control bits at each said receiver with check bits corresponding to the address of the particular receiver and a predetermined sign of said control bit, by counting the number of identities of corresponding bits, with recognition of the inverse of the check bits as providing identities in the case of the reception of a control bit of sign opposite to said predetermined sign and comparing said address bits with address bits of said message by counting the number of identities of corresponding bits for determining whether or not more than a tolerable number of transmission errors have occurred for response to the message and address receiver. - View Dependent Claims (8)
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Specification