SequenceLinear provides sequenced rotating “staging” control of from 2 to 10 BooleanWritables based upon the status numeric In value (0—100). An adjustable delay time
is also provided. A similar object is the SequenceBinary, which uses a weighted method (vs. rotating) for sequencing.
The SequenceLinear component can be used to support applications that need to sequence 2 to 10 loads or stages in a linear or rotating sequence. With linear sequencing the first stage on will be the last stage off. With rotating sequencing the first stage on will be the first stage off. The In property, which is a StatusNumeric, is used to control the number of stages that should be on. The input range is defined by the InMinimum and InMaximum properties. SequenceLinear is available in the HVAC folder of the kitControl palette.
On and Off setpoints are calculated for each stage by the following Table 10 formulas (this assumes there are 5 outputs defined):
Table 10. SequenceLinear On / Off calculation formulas
| Linear | Rotating | |
|---|---|---|
| range = InMaximum - InMinimum | 100 = 100 - 0 | 100 = 100 - 0 |
| delta = range / NumberOutputs | 20 = 100 / 5 | 20 = 100 / 5 |
| OnSetpointA = 1 * delta | 20 | 20 |
| OnSetpointB = 2 * delta | 40 | 40 |
| OnSetpointC = 3 * delta | 60 | 60 |
| OnSetpointD = 4 * delta | 80 | 80 |
| OnSetpointE = 5 * delta | 100 | 100 |
| OffSetpointA = 0 * delta, 4 * delta | 0 | 80 |
| OffSetpointB = 1 * delta, 3 * delta | 20 | 60 |
| OffSetpointC = 2 * delta, 2 * delta | 40 | 40 |
| OffSetpointD = 3 * delta, 1 * delta | 60 | 20 |
| OffSetpointE = 4 * delta, 0 * delta | 80 | 0 |
Setup of the SequenceLinear object involves configuring the following properties:
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Facets
Used to set the active and inactive text to be used for the Out properties.
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In
Input property that is used to determine the number of stages that should currently be On.
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In Minimum
Value of the input that produces all outputs off.
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In Humidity
Value of the input that produces all outputs on.
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Number Outputs
This object can be configured to support 2 to 10 outputs or stages.
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OutA - OutJ
These are status boolean values that can be used to control 2 to 10 loads. The number of outputs used is defined by the Number Outputs property.
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Delay
Defines the amount of time the must pass between changes in outputs.
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On Delay Active
Boolean read-only property that indicates that the on delay timer is active.
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Off Delay Active
Boolean read-only property that indicates that the off delay timer is active.
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Desired Stages On
Read-only property that indicates the calculated number of stages that should be on based on the In property.
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Current Stages On
Read-only property that indicates the current number of stages that are currently on. Normally the Current Stages On and the Desired Stages On will be the same. They will be different when going through a transition and the delay timer is active.
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Next Stage On
Read-only property that indicates the next stage that will be turned on if needed. This is primarily used when the Action is selected to be Rotating.
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Next Stage Off
Read-only property that indicates the next stage that will be turned off if needed. This is primarily used when the Action is selected to be Rotating.
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Action
This configuration property selects between Linear and Rotating action. With Linear action, Out A (Stage 1) will always be the first stage to turn on and the last stage to turn off. With Rotating action, the first stage to turn on will increment to the next stage each time the current stages on goes to 0.
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Rotate Time
This configuration property specifies the amount of time that the outputs will remain in a fixed configuration before the outputs are shifted to the next configuration.
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Rotate Timer Active
Read-only property that indicates that the rotate timer is active.
An example of a SequenceLinear property sheet is shown in Figure 44.
