Option 3.2.3. Select Device Point Analog Deadband/Poll after Set/Delay Load

1 Analog deadband
2 Poll after set
3 Delay load
1 Analog deadband

Analog Deadband filters out changes in the raw value of the configured point.

If a point value change is less than OR EQUAL TO the deadband, the value will be ignored. The raw value must change more than the analog deadband value before the point value is updated in the CIMPLICITY point database.

Therefore, the analog deadband can make CIMPLICITY software ignore small fluctuations in the value of a point.

Example

A point ranges from 0 to 10,000.

Analog deadband = 5

Any point fluctuations of less than 5 are ignored.

Note: An explicit deadband of 0 is the same as selecting an On Change update criteria.
2 Poll after set

Poll After Set determines when CIMPLICITY will read a setpoint value.

Options for the Poll After Set check box are:

Check box status CIMPLICITY will read the point's value
Check Immediately after a Setpoint is performed.
Clear On the next scan or when the trigger condition for the point is set to TRUE.
Important:
  • Point Bridge does not support Poll After Set. If you are defining a Point Bridge point, clear this check box.
  • If you use Poll After Set with the OPC client device communications, you may decrease performance. Using Poll After Set with OPC device communications is not recommended.
3 Delay Load

When Delay Load is checked on the Device tab in the Point Properties dialog box, the point will write to the point database, but is not loaded into memory until demanded by an application.

This option is not recommended for points that are accessed often because there may be a delay time when the point is demanded and loading.

Important: Manual mode is not supported on delay load points.

There are a number of benefits to using the delay-load option, along with some disadvantages and non-supported functions. They are as follows:

Benefits Disadvantages Non-Supported Functions
  • Loaded when needed
  • No memory usage until point is loaded
  • Written to point database
  • Available in point list
  • Slower access
  • Trigger settings and
  • Alarm options are not available
  • Trend buffering
  • Alarming
  • Cannot be used within another point's configuration, e.g. Safety point, Trigger, Availability Trigger point, etc.
  • Cannot be used in a calculation point equation
  • Manual Mode