Step 3.1.3. Select Update Criteria for a Device Point

The update selection determines when the point value will be updated.

Selections in the drop down field are as follows.

Criteria	Point is updated
On Change (Default)
Data Collected	At a regular interval. The interval equals the base scan rate for the port on which the device is located multiplied by the scan rate for the point.
Value Updated	Only when the value changes.
	This is an efficient criterion.
On Scan
Data Collected	At a regular interval. The interval equals the base scan rate for the port on which the device is located multiplied by the scan rate for the point.
Value Updated	The point's value is updated at the point's scan interval, whether or not the value changes. Because this can increase system load, it is recommended that you use On Scan sparingly or not at all.
On Demand On Scan
Data Collected	Whenever the point's value is needed by an application.
Value Updated	At the point's scan interval, whether or not the value changes.
On Demand On Change
Data Collected	Whenever the point's value is needed by an application.
Value Updated	Only when the value changes.
Unsolicited
Value Updated	Whenever the device communications receives data from the PLC, it immediately sends it to CIMPLICITY Point Management whether or not the point's value has changed. This mode is only valid if the device is capable of sending unsolicited updates of point values and the device communications protocol. See the CIMPLICITY Device Communication documentation for your particular device and protocol to see if it supports unsolicited communications.
Unsolicited On Change
Value Updated	Whenever the device communications receives data from the PLC, it evaluates the point and sends it to CIMPLICITY Point Management only it the point's value has changed. This mode is only valid if the device is capable of sending unsolicited updates of point values and the device communications protocol supports it. See the CIMPLICITY Device Communication documentation for your particular device and protocol to see if it supports unsolicited communications.
Poll Once
Data Collected	Polled once when the device communications enabler starts up. Thereafter, it may be updated by unsolicited data from the device. If you select Poll After Set, it will also be updated after a user performs a Setpoint on the point.