A set of standards for industrial telecommunication. In IoT, OPC is used for interoperability between various industrial devices, systems, and networks, facilitating data collection and exchange in manufacturing and industrial environments.
OPC UA (OPC Unified Architecture) is a cross-platform, open-source, IEC62541 standard for data exchange and replaces OPC DA (OPC Data Access), which provides specifications for communicating real-time data (not historical data, alarms or events). There are three important specifications in OPC UA:
- Data Access specification describes the classic exchange of current data. A value can be read and written for each data point. A data point value is described by the actual value, the time stamp at which the value was current and by the quality, which describes whether the value is valid.
- Historical Access allows historical values to be queried if the server has the internal data memory required. A client that reads historical data points via Historical Access also transfers the desired time span to the server in addition to the data point information (Not implemented in the RAYVEN OPC node).
- Alarms and Conditions defines a standardized model for alarm messages and alarm logic. For OPC client applications this simplifies the task of generating alarms from data point values because the logic can be implemented by the OPC server and not by the manufacturer of the client software (Not implemented in the RAYVEN OPC node).
Inputs
The OPC node has both mandatory and optional inputs. These are:
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Input |
Requirement |
Comments |
|
Tag Name |
Mandatory |
The OPC signal name |
|
Field Name |
Mandatory |
Name for the resultant JSON field |
You must identify at least one OPC signal to read and can add additional signals by clicking on the ⊕ Add Value button.
Functionality
The OPC node will make requests at the specified update rate for the designated signal fields.
Outputs
Each OPC signal field will be returned as a separate field (defined by ‘Field Name’) and added to the JSON object.
How to Use
Implementation
Prior to setting up the OPC node, you should have at least one device configured with an IP address. To set the port, add a colon and the port to the end of the address for example: mydomain.com:135.
In the Rayven Workflow Builder:
- Select Inputs.
- Drag the OPC node to the canvas.
- Double click on the OPC node to open the configuration window
Configuration
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Section: General |
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This section contains basic configuration elements required for any OPC implementation |
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Field |
Requirement |
Comments |
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Name |
Mandatory |
Enter a name for this node. This provides a handle to which you and others can refer, so it should be simple but meaningful and explain the node’s purpose. |
|
Update Rate (minutes) |
Mandatory |
Define the interval between requests (in minutes). For example ‘5’ will result in a request every 5 minutes. |
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User Name |
Optional |
Enter the username that was set in the OPC server. |
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Password |
Optional |
Enter the password that was set in the OPC server. |
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Tag Name |
Mandatory |
The OPC signal name |
|
Field Name |
Mandatory |
Name for the resultant JSON field |
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Section: Activation |
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This section contains basic configuration elements required for any Trigger node activation |
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Field |
Requirement |
Comments |
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Logical Operand |
Mandatory |
Select the logical operand from the dropdown list
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Select Device Filter |
Mandatory |
Select Device Filter configured in Device Management to select the devices that will receive this payload. |
Activation
Once the node has been configured, click the Activate button and then click Save. The node is ready to receive data into the workflow.