Workspaces ---- apbd asves asvpapers bear blast caltrop cases concurrency cosi dif diva dopcenter dopresence dopsysadmin eecsx44 elab embedded embeddedadmin giotto hyinfo m2t2 mescal metropolis mica mobies msgadmin murieh mvsis nephest ransom recons robosysadmin savg sec seminar smartnets video webmaster

Communication Structures for Wired Building Automation Network Design The specification of a communication problem is captured by end-to-end requirements among sensors, actuators and controllers. A specificaiton contains nodes and links representing end-to-end constraints. Section Communication Specification define a precise model to capture a specification. A platform instance is captured by a communication structure that includes the information of the component name and type. Links are actual wires and they are annotated wiht a cosi::WiringPath. A wire in the platform can accomodate many different wiring path, therefore, when instantiated, a wire has an "any value" wiring path. Section Communication Platform Instance describes the communication structure that is used to capture a platform instance. The wiring path is then assigned by an algorithm that computes the actual layout of a wire. The implementation is captured by a communication structure that combines the properties of the specification and the platform instance. Nodes are labeled by threads that bear the information on period and length of messages, and links are labeled by wiring paths. Section Communication Implementation describe the communication structure that is used to capture and implementation. Communication Specification The specification of a wired building automation system synthesis problem is a communication structure labeled by cosi::commstruct::wiredbas::SpecificationLabel. The meaning of the labels is the following: cosi::Type is a string that defines the type of a component (e.g. "Sensor" or "Controller"). cosi::Position contains the value of the three coordinates x, y, z associated with a node. cosi::Ports is the required set of ports for each node. A port is a pair of two strings that representing the name and the type of a componenent. This ports are the ones that are required by specification and do not represent the actual ports that a component has. The same label is used to specify the connection between links and nodes. cosi::ThreadSet is a set of communication thread that run on the node. A communication thread is defiened by the class cosi::Thread and contains the following information: ThreadName is the name of the thread. DestinationNodeName is the name of the destination node to which messages must be sent. DestinationThreadName is the name of the thread running on the destination node that receives the messages. Period is the interval of time between two messages. MsgLength is the length of messages in bits. cosi::RealLatency is the maximum latency that is accepted for an end-to-end requirement. Figure_bas_spec_example : Example of end-to-end requirement specificaiton for building autoamtion systems Figure_bas_spec_example shows an example of specification. The specification contains three nodes: a sensor named TempSens1, a controller names Ctrl and an actuatuator names Damper1. The sensor is a source of messages that are generated by a thread with name Thread1. This thread sends messages every 40 seconds to thread GetTempSens1 running on the controller. Each message is 8 bit long. The sensor is in position (0,0,1) and has one output port only. The maximum lantency of the massages is 2 second and it is specified on the link between the sensor and the controller. The link is bound to output port P1 of the sensor and input port P1 of the controller. Notice that the same label cosi::Ports is used to specify the ports of a node and the ports to which a link is bound. Notice that the links are only logical end-to-end connections between nodes. They represent connectivity requirements. Composition of Specifications The composition code can be found in cosi::commstruct::wiredbas::Specification::operator+. The composition of two specifications relies on the definition of the composition of the single quantities and is defined as follows: For each node in common, if they have the same type, name and position Assing name, type and position Take the union of the ports (defined in cosi::Ports::operator+) Take the union of Threads (defined in cosi::ThreadSet::operator+) For each link in common Take the minimum of the two latencies (defined in cosi::RealLatency::operator+) For components that are not in common Inherit the label of the communication structure the component belongs to. Communication Platform Instance Components of a platform instance are labeled by cosi::commstruct::wiredbas::PlatformLabel. We recall that the platform is a container, therefore nodes do not have threads assigned to them. Also, since the latency of a wire depends on the wiring path, protocol etc, there is no latency attached to a platform instance. On the other hand, the platform must expose the capabilities of the components. Therefore, each component should be labeled with quantities like: Largest set of ports Maximum numeber of threads Maximum length of a wiring path, maximum number of turns of a wiring path etc. These limitations are captured by models. Here, we define a minimum set of labels that are required for a platform instance. The labels are: cosi::Name is the component name. Each library element has a component name associated with it that identifies the library element. For instance, a specific temperature sensor may be labeled with "InfraSense50". cosi::Type is the components type. Each library element has a component type associated with it. For instnace, a temperature sensor may be labeld with type "Sensor". cosi::Ports is the set of ports offered by a component. A component may come in different configurations with a different set of available ports. This label should capture the largest set of ports. This label is also used to specify the connection between links and nodes (i.e. the output port of a source node and the input port of a destination port that represent the extremities of a link). cosi::WiringPath is the path followed by a wired from one source point to a destination point. Composition of Platform Instances Platform instances can be component to form other platform instances. The composition is not constrainted by any rule at the moment. This is still to be defined. The composition is defined similarly to the composition of specifications with the important difference that the ports of the nodes in common between the two communication structures must also be the same (containement may be considered instead of equality). For each node in common, if they have the same type, name, position and ports Assign ports, type, name and position. For each link in common If the wiring path has the same starting and ending points, take the shortest wiring path. For components that are not in common Inherit the label of the communication structure the component belongs to. Communication Implementation The implementation is the result of mapping the specification on a platform instance. It contains some quantities from the specification and some from the platform instance. In particular it contains the following: cosi::Name, cosi::Type, cosi::Position, cosi::Ports cosi::ThreadSet cosi::WiringPath that is essential for the computation of cost and performance. cosi::TransferTable is a set of 3-tuple. Each entry of the tranfer table contains the follwing fields SourceName is the name of the node that originated the message DestName is the name of the node that is the recipient of the message PortName is the name of the port to which the message has to be sent Composition of Implementations The composition of two implementations inherits its semantics from the composition of specificatio and palatform instances: For each node in common, if they have the same type, name, position and ports Assign ports, type, name and position. Take the union of Threads (defined in cosi::ThreadSet::operator+) For each link in common If the wiring path has the same starting and ending points, take the shortest wiring path. For components that are not in common Inherit the label of the communication structure the component belongs to.

Contact

©2002-2018 U.C. Regents