DeadbandSwitch (BDeadbandSwitch)

This block evaluates the Test In value to determine whether the value is within a range of values. The block supports both value and trend requests.

If the value is within the range, the output reports the True In value, otherwise the output reports the False In value. If the True In slot is not linked, the block reports the default true numeric value one (1). If the False In slot is not linked, the block reports a default false numeric value of zero (0).

For trend requests, at least one of the inputs (In1 or In2) must map to a trend.

The Deadband Switch Block is similar to the Range Switch Block, except the high and low limits are calculated from a baseline and deadband instead of configuring independent high and low limits.

The range of values is determined based on the Baseline In, Deadband In, Deadband Mode and Percent Mode properties. Deadband Mode determines if the Deadband In value is an absolute value or a percentage. Percent Mode determines if the percent value is expressed as a decimal (0-1) or a percentage (0-100).

The following table provides an example of how all the properties work together to configure a deadband range.

Deadband configuration

Baseline In Deadband In Deadband Mode Percent Mode Range Min Range Max Calculated Range
72 5 Absolute N/A Baseline — Deadband Baseline — Deadband 67–77
72 5 Percent Percent Baseline — (Baseline * (Deadband/100)) Baseline — (Baseline * (Deadband/100)) 68.4–75.6
72 0.05 Percent Decimal Baseline — (Baseline * Deadband) Baseline — (Baseline * Deadband) 68.4–75.6
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To view these properties, double-click the block on the Wire Sheet or the block name in the Nav tree.

Property Value Description
Out read-only value slot Outputs either the True In or False In value based on evaluating the Boolean condition.
Test In required value slot Links from the output of other logic blocks or data sources to supply one or more input values to be tested for validity in the logic block.
Baseline In required numeric value slot Links from the output of other logic blocks or data sources to supply a trend. This trend provides a baseline value upon which to apply a deadband.
Deadband In required numeric value slot Links from the output of other logic blocks or data sources to supply one or more input values that represent a dead or neutral zone around a baseline.
True In optional value slot (defaults to True if unlinked) Links from the output of other logic blocks or data sources to supply one or more valid values to the logic block.
False In optional value slot (defaults to False if unlinked) Links from the output of other logic blocks or data sources to supply one or more invalid values to a logic block.
Deadband Mode drop-down list (defaults to Absolute) Determines what the engine uses to establish the deadband.

Absolute, configures a specific value to use as the deadband.

Percent, configures the deadband as a percentage.

Percent Mode drop-down list (defaults to Percent) Determines the form in which the constant appears if Deadband Mode is a percentage.

Percent treats the value as a percent (0‐100). For example, value of 30% would be represented as 30.

Decimal treats the value as a decimal number (0‐1). For example, a value of 30% would be represented as .3.

Example

Consider three numeric points with numeric interval histories for Zone Temp tagged with hs:zoneAirTempSensor and a:a marker tags, a baseline value of 72 (b:Baseline and a:a marker tags) and a deadband value of 5 (b:Deadband and a:a marker tags). The algorithm looks like this:

Figure 201.   Deadband algorithm
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A numeric point with an Analytic Proxy Ext is configured with Data = alg:DeadbandSwitch, Time Range = yesterdayand Rollup = Sum. The algorithm result is the sum of the true (1) and false (0) values during the time range, which indicates how many 15-minute intervals that the Zone Temp value was within the calculated range.

Figure 202.   Deadband Numeric Point
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