Serial bus communication method in a refrigeration system
First Claim
1. A method of two-way communication in a refrigeration system between a central communication node and remote nodes via serial data bus using a modified Controller Area Network protocol having a fixed message frame format which includes a combined identification and arbitration field and a data field, comprising the steps of:
- converting a predetermined portion of the data field of each message frame to a permanent data descriptor expansion byte (DEB),setting a predetermined bit of said DEB to a first logic level in at least the first frame of a message, to indicate a control frame,loading information descriptive of the message in the remaining bits of said DEB, and in the remaining data field, of said control frame,said message descriptive information in the data field of the control frame including an algorithm and algorithm block number associated with the data being transmitted, when the data is being transmitted from and to the central communication node,setting said predetermined bit of said DEB to a second logic level in at least one subsequent frame of the message, to indicate a data frame,loading a block of data in the data field of each data frame,and loading index information in the remaining bits of the DEB in each data frame which is specific to the data of the associated data frame.
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Accused Products
Abstract
A method of communication in a refrigeration system, between communication nodes connected to a serial data bus using Controller Area Network protocol (CAN) having a message frame format which includes a data field. The method includes converting a byte of the data field of each message frame to a permanent data descriptor expansion byte (DEB). In at least the first frame of a message a specific bit of the DEB is set to a first logic level to indicate a control frame, and information descriptive of the whole message is loaded into the remaining bits of the DEB, and data field. In each remaining frame of a message following a control frame, or control frames, the specific bit is set to a second logic level, to indicate a data frame. A block of data is loaded into the data field of each data frame, and index information specific to the associated block of data is loaded into the remaining bits of the DEB.
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Citations
8 Claims
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1. A method of two-way communication in a refrigeration system between a central communication node and remote nodes via serial data bus using a modified Controller Area Network protocol having a fixed message frame format which includes a combined identification and arbitration field and a data field, comprising the steps of:
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converting a predetermined portion of the data field of each message frame to a permanent data descriptor expansion byte (DEB), setting a predetermined bit of said DEB to a first logic level in at least the first frame of a message, to indicate a control frame, loading information descriptive of the message in the remaining bits of said DEB, and in the remaining data field, of said control frame, said message descriptive information in the data field of the control frame including an algorithm and algorithm block number associated with the data being transmitted, when the data is being transmitted from and to the central communication node, setting said predetermined bit of said DEB to a second logic level in at least one subsequent frame of the message, to indicate a data frame, loading a block of data in the data field of each data frame, and loading index information in the remaining bits of the DEB in each data frame which is specific to the data of the associated data frame.
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2. A method of two-way communication in a refrigeration system between a central communication node and remote nodes via serial data bus using a modified Controller Area Network protocol having a fixed message frame format which includes a combined identification and arbitration field and a data field, comprising the steps of:
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converting a predetermined portion of the data field of each message frame to a permanent data descriptor expansion byte (DEB), setting a predetermined bit of said DEB to a first logic level in at least the first frame of a message, to indicate a control frame, loading information descriptive of the message in the remaining bits of said DEB, and in the remaining data field, of said control frame, said message descriptive information in the data field of the control frame of a message transmitted by a remote node indicating when the message is a request for data to be sent from the central communication node, setting said predetermined bit of said DEB to a second logic level in at least one subsequent frame of the message, to indicate a data frame, loading a block of data in the data field of each data frame, and loading index information in the remaining bits of the DEB in each data frame which is specific to the data of the associated data frame. - View Dependent Claims (3)
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4. A method of two-way communication in a refrigeration system between a central communication node and remote nodes via serial data bus using a modified Controller Area Network protocol having a fixed message frame format which includes a combined identification and arbitration field and a data field, comprising the steps of:
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converting a predetermined portion of the data field of each message frame to a permanent data descriptor expansion byte (DEB), setting a predetermined bit of said DEB to a first logic level in at least the first frame of a message, to indicate a control frame, loading information descriptive of the message in the remaining bits of said DEB, and in the remaining data field, of said control frame, said message descriptive information in the data field of the control frame of a message transmitted by a remote node indicating when the message is sending data to be stored at the central communication node, setting said predetermined bit of said DEB to a second logic level in at least one subsequent frame of the message, to indicate a data frame, loading a block of data in the data field of each data frame, and loading index information in the remaining bits of the DEB in each data frame which is specific to the data of the associated data frame. - View Dependent Claims (5, 6)
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7. A method of two-way communication in a refrigeration system between a central communication node and remote nodes, with one of the nodes being a data logger, via serial data bus using a modified Controller Area Network protocol having a fixed message frame format which includes a combined identification and arbitration field and a data field, comprising the steps of:
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converting a predetermined portion of the data field of each message frame to a permanent data descriptor expansion byte (DEB), setting a predetermined bit of said DEB to a first logic level in at least the first frame of a message, to indicate a control frame, loading information descriptive of the message in the remaining bits of said DEB, and in the remaining data field, of said control frame, said message descriptive information in the data field of the control frame of a message transmitted by a remote node indicating when the message is a request for a data logger transmission, setting said predetermined bit of said DEB to a second logic level in at least one subsequent frame of the message, to indicate a data frame, loading a block of data in the data field of each data frame, and loading index information in the remaining bits of the DEB in each data frame which is specific to the data of the associated data frame. - View Dependent Claims (8)
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Specification