Adding an OPC group

  1. Select Configuration > OPC > OPC Clients. The OPC Clients screen is displayed.
  2. Select a record and click OPC Servers. The OPC Servers screen is displayed at the bottom.
  3. Select a record and click OPC Groups. The OPC Groups screen is displayed at the bottom.
  4. Click Add. The Add window is displayed.
  5. Specify this information:
    OPC Group
    The name for the OPC group.
    Notify Mode
    Indicate how the OPC items in the OPC groups are updated.

    Possible values:

    • Individual notify: The OPC client subscribes to specific tags and notifies the OPC server. When the value of any of these tags changes, the OPC server immediately notifies the OPC client. Multiple tags can be part of the same group, and each tag notifies the OPC client independently when changed. The changes made to one tag do not affect notifications of other tags within the same group.
    • Group read on timer: The OPC client reads each OPC item in the OPC group at a fixed interval (‘x’ milliseconds), where ‘x’ is configurable for the OPC group. All OPC items within the group are read at the same frequency.
    • Group read on notify: In a group of tags, one tag must be designated as the notifying tag. The OPC client informs the OPC server that it has subscribed to this notifying tag. When the value of the notifying tag changes, the OPC client requests the values for all tags in the group. However, if the values of the other tags in the group change, the OPC client does not receive a notification. The values of the other tags are only read when the notifying tag changes.
    • Individual write: The OPC tags that the MES sends data to, such as recipe data or machine settings, are communicated back to the PLC for automated production processes.
    Active
    If this check box is selected, the application performs read or write operations on the OPC group.
    Transactional

    If this check box is selected, all items in the OPC group are considered as part of a single transaction. This is useful for rollback process.

    Deadband
    A percentage (0–100) that defines the minimum data change required to notify the client. If scaling is enabled, the threshold is based on the scaled range. If scaling is disabled, the threshold is based on the full data-type range. This field must be specified only if the OPC server supports deadband functionality.
    History Recorded
    If this check box is selected, historical data is recorded for all items in the OPC group.
  6. Click OK.