Method and apparatus using network variables in a multi-node network

• US 5,513,324 A
• Filed: 03/07/1994
• Issued: 04/30/1996
• Est. Priority Date: 03/18/1991
• Status: Expired due to Term

• Current Assignee: Echelon Systems Corp.
• Original Assignee: Echelon Systems Corp.
• Inventors: Riley, Glen M., Dolin, Robert A. Jr., Einkauf, Robert L., Von De Bur, James M., Kagan, Richard S.
• Primary Examiner(s): Harrell, Robert B.
• Application Number:
  US08/207,229
• Time in Patent Office: 785 Days
• Field of Search: 364/DIG. 1 MS File, 364/DIG. 2 MS File, 395/200.01, 395/200.05, 395/200.08, 395/200.09, 395/200.15, 395/200.18, 395/280, 395/800
• US Class Current: 709/237
• CPC Class Codes: G05B 19/4185 characterised by the network communication
• CPC Class Codes: G06F 15/17381 Two dimensional, e.g. mesh, torus
• CPC Class Codes: G06F 9/547 Remote procedure calls [RPC]; Web services
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

An improved apparatus and method for communicating information in a networked system wherein network variables are employed to accomplish such communication. Network variables allow for standardized communication of data between nodes in a network. A first node may be programmed, for example, to sense certain information and to report the information as a network variable X. A second node may be programmed to receive the variable X and to control devices based on the current value of the variable. The present invention provides for defining connections between the first and second node to facilitate such communication and for determining addressing information to allow for addressing of messages, including updates to the value of the variable X, between the nodes.

Claims

1. A network for communicating a network variable V, said variable V having a value, said network comprising:

a first node addressable by a first network address;

a second node addressable by a second network address;

a communications medium;

said first node being coupled to said communications medium, said first node having

a first memory having a first storage location for storing a value of a variable V, said first memory further having an address table for storing said second network address, said first memory further having a network variable table for storing variable identification information for identifying said variable V and for storing address table index information corresponding to said variable identification information,

a first processor being coupled to said memory, said processor for writing to said first storage location with a first value of said variable V, said processor further for generating a communications packet responsive to said first value being written to said first memory, said communications packet including said first value and identification information identifying said first value as being a value of variable V, and

a first network communications circuit being coupled to said processor and to said communications medium, said network communications circuit for communicating said communications packet onto said communications medium responsive to receiving said communications packet from said first processor, and

said second node being coupled to said communications medium, said second node having

a second network communications circuit being coupled to said communications medium for receiving said communications packet,

a second memory having a second storage location for storing a value of said variable V, and

a processor being coupled to said second network communications circuit and said second memory, said processor for extracting said first value from said received communications packet, said processor further for writing said first value to said second storage location responsive to extracting said first value from said received communications packet.

2. The network of claim 1 wherein said variable V is defined as an output variable for said first node, wherein said variable V is defined as an input variable for said second node, wherein said second node includes a second index table, and wherein said second node does not index said second address table responsive to receiving said message packet.

3. The network of claim 2 wherein a relationship between said first node having a first storage location for storing a value of said variable V, and said second node having a second storage location for storing a value of said variable V, is established by defining a connection, said connection including a reference to said first node, a reference to said second node, and a reference to said variable V.

4. The network of claim 3 wherein said first storage location is for storing an old value of said variable V, and wherein said said first value is different than said old value.

5. The network of claim 2 wherein said second network address is a group address.

20. The network as recited by claim 1 wherein said identification information is a network variable id comprising 14 bits of information.

6. A method for providing communication between a first node and a second node in a network, said first node coupled in communication with said second node through a medium, said first node comprising a first processor for processing a first process, a first memory for storing a first network variable, said first process writing said first network variable to said first memory, and a first communication port for communicating information onto said medium, said second node comprising a second processor for processing a second process, a second memory for storing a second network variable, said second process reading said second network variable from said second memory, and a second communication port for receiving information from said medium, said method comprising the steps of:

(a) said first node storing a first computer program on said first node, said first computer program for execution by said first processor as said first process;

(b) said second node storing a second computer program on said second node, said second computer program for execution by said second processor as said second process;

(c) defining a relationship between said first network variable and said second network variable, said relationship including a connection, and

(d) binding said first network variable with said second network variable, said binding creating an association between said first network variable and said second network variable, said binding including steps of

accessing said connection, and

assigning an addressing mode for said first network variable and said second network variable.

7. The method as recited by claim 6 wherein, said first memory further for storing a list of nodes a first and second list of network variables and a set of connections, said list of nodes including information identifying said fast node and said second node, said step of logically connecting said first network variable with said second network variable comprises the steps of:

(a) a computer process defining in said binding script a connection name, said connection name for identifying said connection;

(b) said computer process selecting said first node from said list of nodes;

(c) said computer process selecting said first network variable from said first list of network variables;

(d) said computer process selecting said second node from said list of nodes;

(e) said computer process selecting said second network variable from said second list of network variables;

(f) said steps (a)-(e) defining a connection; and

(g) said computer process adding said connection to said set of connections.

8. The method as recited by claim 7 wherein said step of binding said first network variable with said second network variable comprises the steps of:

(a) a computer process performing edit checks on said connection;

(b) said computer process assigning identification information to said connection, said identification information uniquely identifying said connection to said first node and said second node, and

(c) said computer process determining an addressing mode for messages associated with said connection.

9. The method as recited by claim 8 wherein said addressing mode is determined to include a group addressing mode and said method further comprises the step of assigning a group address to said connection.

10. The method as recited by claim 8 further comprising the step of storing said identification information in a network variable table subsequent to assigning said identification information to said connection.

11. The method as recited by claim 8 further comprising the step of storing address information in an address table subsequent to determining said addressing mode.

12. A method of providing shared data from a first node of a network to a second node of said network, said first node comprising a first data storage device coupled to a first processor, said second node comprising a second data storage device coupled to a second processor, said first and second processors coupled to said network, comprising the steps of:

a) declaring, in a binding script, a first node W as a writer of a variable V;

b) declaring, in said binding script, a second node R as a reader of said variable V;

c) said first processor allocating first storage S 1 on said first node W for storage of said variable V;

d) said second processor allocating second storage S2 on said second node R for storage of variable V;

e) said first node modifying said first storage S1 with a new value for said variable V;

f) said first node W transmitting a message on said network responsive to modifying said storage S1, said message comprising said new value for said variable V;

g) said second node R receiving said message, and

h) said second node modifying said second storage S2 with said new value for said variable V responsive to receiving said message.

13. The method of claim 12 further including a step of defining a connection, said step of defining a connection including:

defining a connection name;

selecting said first node W;

selecting a first network variable name for said first node W;

selecting said second node R;

selecting a second network variable name for said second node W, and

setting parameters.

14. The method of claim 13 further including a step of generating a binding script, said step of generating a binding script including:

accessing said connection;

assigning an address, and

assigning a network variable identification to said connection.

15. The method as recited by claim 12 wherein said message further comprises identifying information for identifying said variable V.

16. The method as recited by claim 12 further comprising the step of declaring a type of communication service for said message wherein said type of communication service is declared as configurable.

17. The method as recited by claim 12 further comprising the step of declaring an authentication parameter for said message wherein said authentication parameter is declared as configurable.

18. The method as recited by claim 12 further comprising the step of declaring a priority parameter for said message wherein said priority parameter is declared as configurable.

19. A network for communicating information, said network comprising at least a first node and a second node, said first node comprising:

(a) first data storage means having a first storage location for storing a variable V;

(b) first processing means coupled with said first data storage means, said first processing means for writing said first storage location with a new value A, said first processing means further for assembling a communication packet for transmission on said network responsive to said new value A being written to said first storage location, said communication packet comprising said new value A and identification information identifying said new value A as being associated with said variable V;

(c) first communication means coupled with said first processing means, said first communication means further coupled with a medium, said first communication means for receiving said communication packet from said first processing means and for communicating said communication packet onto said medium;

(d) an address table for storing addressing information of said second node;

(e) a network variable table having identification information for identifying said variable V, said network variable table further having information corresponding to said identification information for indexing said address table, and

said second node comprising;

(f) second data storage means for storing said variable V;

(g) second communication means coupled with said medium for receiving said communication packet on said medium;

(h) second processing means coupled with said second communication means for receiving said communication packet from said second communication means, said second processing means further coupled with said second data storage means, said second processing means writing said second data storage means with said new value A responsive to receiving said communication packet.

21. A network of nodes for communicating, controlling and sensing information, said network comprising a first node and a second node, said first node and said second node coupled in communication over a communication medium, said first node comprising:

(a) an internal communication bus for communicating information;

(b) storage means for storing at least information on a first network variable, said information on said first network variable comprises at least variable type identifying information, said storage means coupled in communication with said internal communication bus;

(c) interface means coupled in communication with said medium for receiving a first command and for providing said first command to a processing means, said interface means further coupled in communication with said internal communication bus for receiving said information on said first network variable and for outputting said information on said first network variable on said medium responsive to receiving said information on said first network variable, and

(d) said processing means for processing information, said processing means coupled in communication with said internal communication bus to receive said first command and to communicate a request to read said first network variable from said storage means responsive to receiving said first command, said information on said first network variable being communicated to said interface means for communication on said medium.

22. The network as recited by claim 21 wherein said variable type information is one of a set of standard variable types defined for said network.

23. A method for configuring nodes of a network, said network comprising a first node and a second node, said first node and said second node coupled in communication with a medium, said first node comprising first storage for storing a first variable, said method comprising the steps of:

(a) a network management node communicating a first command to said first node on said medium, said first command requesting said first node communicate configuration information to said network management node;

(b) said first node receiving said first command;

(c) said first node communicating configuration information regarding said first variable responsive to receiving said first command, said configuration information including variable type information, and

(d) said network management node providing for configuration of said network to allow communication of said first variable between said first node and said second node.

24. The method as recited by claim 23 wherein said variable type information is one of a set of standard variable types defined for said network.

25. In a networked communication system comprising at least a first node, a second node and a network management node, said network management node comprising data storage for storing data information including a first list of data types, a method of configuring said networked communication system comprising the steps of:

(a) said network management node communicating a command to said first node requesting said first node to respond by transmitting a second list of data items used by said first node;

(b) said first node receiving said command, and

(c) said first node transmitting said second list responsive to receiving said command, said second list comprising information identifying a data type of each of said data items in said second list.

26. The networked communication system of claim 25 wherein said first list is included in a binder interface file (BIF).

27. The networked communication system of claim 25 wherein said second list is included in a binder interface file (BIF).

28. A network system that includes a plurality of nodes coupled for communication, said plurality of nodes including:

a writer node having a first storage location corresponding to a variable; and

a reader node having a second storage location corresponding to said variable;

said reader node being configured to transmit a polling message to said writer node, said polling message identifying said variable;

said writer node being configured to read a value from said first storage location and transmit a message containing said value to said reader node in response to receiving said polling message; and

said reader node being configured to read said value from said message and store said value in said second storage location.

29. The network system of claim 28 wherein said writer node is further configured to read said value from said first storage location and send said message containing said value to said reader node in response to said value being written into said first storage location.

30. The network system of claim 28 wherein:

said writer node has an address on said network system;

said reader node includes

a network address table, said network address table including a first entry, said first entry storing the address of the writer node;

a network variable table, said network variable table having a second entry, said second entry storing a network variable identifier for the network variable;

an index that associates the first entry and the second entry;

said reader node is configured to construct said polling message by

inspecting the first entry to determine the network variable identifier for the network variable;

inspecting the index to identify the first entry;

inspecting the first entry to determine the address of the writer node; and

said reader node transmits said polling message to the address of the writer node, said packet including the network variable identifier.

31. A network system that includes a plurality of nodes coupled for communication, said plurality of nodes including:

a first node having a first storage location corresponding to a variable;

a second node having a second storage location corresponding to said variable;

a third node having a third storage location corresponding to said variable;

said first node being configured to transmit a message containing a value to said second node in response to said value being written to said first storage location;

said second node being configured to read said value from said message, store said value in said second storage location, and transmit a second message containing said value to said third node in response to receiving said first message; and

said third node being configured to read said value from said message and store said value in said third storage location in response to receiving said second message.

32. The network system of claim 31 wherein said second node if further configured to transmit a fourth message containing a second value when said second value is written to said second storage location.

33. In a network system comprising a plurality of nodes, a method for sharing a network variable between a group of nodes, each node in the plurality of nodes having an address on said network, the group of nodes including at least one reader node and at least one writer node, the method comprising the steps of:

if the group of nodes includes a single reader node, then for each writer node in the group of nodes performing the steps of

storing the address of the reader node in a first entry in an address table in the writer node;

storing a network variable identifier for the network variable in a second entry in a network variable table;

creating an index that associates the first entry and the second entry;

detecting when a new value is written to a storage location within the writer node that corresponds to the network variable;

when a new value is written to the storage location within the writer node that corresponds to the network variable, performing the steps of

inspecting the first entry to determine the network variable identifier for the network variable;

inspecting the index to identify the first entry;

inspecting the first entry to determine the address of the reader node; and

transmitting a packet to the group address, said packet including the new value and the network variable identifier.

34. The method of claim 33 wherein each node of said plurality of nodes has an address table and a network variable table, the method further comprising the steps of:

if the group of nodes includes a plurality of reader nodes, then creating a group address for said group of nodes;

for each node in the group of nodes, performing the steps of

storing the group address in a third entry in the address table in the node;

storing the network variable identifier for the network variable in a fourth entry in the network variable table in the node; and

creating an index that associates the third entry and the fourth entry;

for each writer node in said group of nodes, performing the steps of

detecting when a new value is written to a storage location within the writer node that corresponds to the network variable;

when a new value is written to the storage location within the writer node that corresponds to the network variable, performing the steps of

inspecting the third entry to determine the network variable identifier for the network variable;

inspecting the index to identify the third entry;

inspecting the third entry to determine the group address; and

transmitting a packet to the group address, said packet including the new value and the network variable identifier.

35. A method for configuring a network, said network comprising a first node having first storage for storing a first variable of a first type, said first node further having a first processor for manipulating said first variable, said first node further having a first interface for interfacing with a medium to allow a data item stored as said first variable to be communicated onto said medium subsequent to manipulation, said network further comprising a second node having second storage for storing a second variable of said first type, said second node further having a second interface for interfacing with said medium to allow receiving of said data item, said second node further having a processor for storing said data item in said second storage, said method comprising the steps of:

(a) a network management node communicating a first command to said first node on said medium, said first command requesting said first node communicate configuration information to said network management node;

(b) said first node receiving said first command and communicating configuration information regarding said first variable to said network management node;

(c) said network management node communicating a second command to said second node on said medium, said second command requesting said second node communicate configuration information to said network management node;

(d) said second node receiving said second command and communicating configuration information regarding said second variable to said network management node;

(e) defining a relationship between said first variable and said second variable, and

(f) said network management node communicating network address information of said second node to said first node responsive to defining said relationship, said first node storing said address information associated with said first variable.

36. A network system that includes a plurality of nodes coupled for communication, said plurality of nodes including:

a plurality of writer nodes, each of said plurality of writer nodes having a first storage location corresponding to a network variable; and

one or more reader nodes, each of said one or more reader nodes having a second storage location corresponding to said network variable;

each writer node of said plurality of writer nodes being configured to transmit a message containing a value to each of said one or more reader nodes when said value is written to said first storage location on said writer node; and

each reader node of said one or more reader nodes being configured to read said value from said message and copy said value into said second storage location on said reader node.