Update Criteria:

The update criteria determines how the data will be requested. Click the drop-down button to the right of the input field to display your choices, then make a selection.

For device points–Select Unsolicited for the DDE Client communications to send data it receives to Point Management whether or not the point's value has changed..

For device points–Select Unsolicited On Change for the DDE Client communications to send data it receives to Point Management only if the point's value has changed.

For diagnostic points–Select On Change to have the DDE Client Communications poll the values at regular intervals and update only changed values.

For diagnostic points–Select On Scan to have the DDE Client communications poll and update the values at regular intervals, whether or not the values have changed.

For diagnostic points–Select On Demand On Change for the DDE Client Communications to poll values whenever they are needed by an application and to update only changed values.

For diagnostic points–Select On Demand On Scan for the DDE Client Communications to poll and update values when they are needed by an application whether or not the values have changed.

For device points–Select On Demand Unsolicited.

For device points–Select On Demand Unsolicited On Change.

Important: Device points that are configured with an update criteria other than Unsolicited or Unsolicited On Change will be found to be invalid. When using point by address, the point must be configured for an unsolicited update criteria.

Address:

The general point address format is the format of the data item defined by the specific DDE server. See the DDE server documentation for the syntax of the data item.