Configuration

Client Setup

Figure 1. Module Configuration

The OPC XML Client module allows unlimited connections to any number of OPC XML-DA compliant servers. As shown in the above screenshot, new connections can be created by clicking on the burger menu icon. Each connection to a specific OPC XML-DA server is named Client. See below for the requiredsteps when connecting N3uron to an OPC XML-DA server.

Each client requires the following parameters to be configured:

• Enables Data Collection: When disabled, the channel will remain inactive. The default value is set to enabled.
• Override Timestamps: When enabled, timestamps received from the server will be overwritten using the local time.
• Read mode: Specifies the mode for reading data from the server.
  • Polling: Data is read by polling the server using read requests. 
• Max. items per read: Specifies the maximum number of items that can be read in a single request. The default value is 512.
• Connection:
  • Host: Specifies the IP address or host used to connect to the server. The default value is 127.0.0.1.
  • Port: Port used to connect to the server. The valid range is 1-65535. The default value is 80.
• Authentication:
  • Username: Specifies the username to authenticate with the server. 
  • Password: Specifies the password used to authenticate with the server. 

• Timing:
  • Timeout:Maximum time spent waiting for a valid response in milliseconds. The valid range is 100ms to 600,000ms, the default value is 3000ms. 
  • Retry attempts: Number of communication retries before considering the target server unreachable. The valid range is 0 to 100, the default value is 3. 
  • Inter-request delay: Delay before sending the following request to the target server, displayed in milliseconds. The valid range is 0ms to 600,000ms, the default value is 0ms. 

Figure 2. Client Configuration

Tag Configuration

Once the client has been configured, you can start creating tags that are linked to the OPC XML server. Below, you can see an example tag configuration, as well as a brief explanation of each available parameter in the Source section of the OPC XML Client module.

• Source:
  • Enabled: When disabled, tags will not be updated with the values received from the server, but instead, will essentially act as memory tags. When set to Enabled, the tag value will be continuously updated with the values received from the OPC XML server. The default value is set to Disabled.
  • Module type: Defines the driver type used to retrieve values. In this example, OpcXmlClient must be selected from the drop-down menu. If OpcXmlClient does not appear in the drop-down menu, it means that the driver has not yet been installed on this machine and therefore, must be installed.
  • Module name: Users should enter here the name of the previously created OPC XML Client module instance.
  • Config:
    • Client: Enter the name of the client youpreviously created.
    • Address: OPC ItemName.
    • Array: Specifies whether the data type is an array or a scalar value.
    • Index: Defines the data index in the array. This can be a comma-separated list of numbers for accessing a specific element within the multidimensional array. 
    • OPC scan rate: Update rate for this tag, displayed in milliseconds. The minimum value is 100ms.

Figure 3. Tag Configuration