WOLFRAM SYSTEM MODELER
ReadA block for reading data from items on an OPC server at intervals determined by parameter samplePeriod |
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Wolfram Language
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SystemModel["OPCUA.Blocks.SamplerReal.Read"]
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Information
This block reads data of scalar type Real from the OPC UA server it is connected to. It inherits the properties of the partial model Sampler, which contains parameters such as samplePeriod, nodeID, nodeNamespace, and nodeIDType that determine how often and from which OPC node the data should be read. Only scalar nodes can be read; i.e. no array or matrix nodes are supported.
At every sampling instant, external function readExternalReal is called from within the block.
Relevant Parameters
- samplePeriod: determines how often to sample data from the OPC node
- startTime: when the block should start to read data
- nodeID: which OPC UA node to read data from (ID value should always be inside quotes)
- nodeNamespace: which namespace the node is located in
- nodeIDType: which ID type to use, numeric or string
Interfaces
- y: a Real output, which is the sampled signal
- serverID: the connector that connects the block to the OPC UA server component
Parameters (6)
| samplePeriod |
Value: Type: Time (s) Description: Sample period of component |
|---|---|
| startTime |
Value: 0 Type: Time (s) Description: First sample time instant |
| nodeIDType |
Value: Type: UANodeIdType Description: The node identifier type |
| nodeID |
Value: Type: String Description: The node identifier |
| nodeNamespace |
Value: Type: Integer Description: The node namespace |
| y_start |
Value: Type: Real Description: Initial value of output signal |
Outputs (2)
| sampleTrigger |
Type: Boolean Description: True, if sample time instant |
|---|---|
| firstTrigger |
Type: Boolean Description: Rising edge signals first sample instant |
Connectors (2)
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serverID |
Type: BlockConnector Description: The unique ID of the server the block is connected to |
|---|---|---|
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y |
Type: RealOutput Description: The data read from the item on the OPC server |
Used in Examples (4)
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OPCUA.Examples Basic example that demonstrates how to write to and read from nodes on an OPC UA server |
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OPCUA.Examples Example that demonstrates a possible use of multiple OPC UA servers |
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OPCUA.Examples A tank system model where height data is written to and read from an OPC UA node on an OPC UA server |
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OPCUA.Examples Example that demonstrates the interaction of an OPC UA server with a Raspberry Pi |