ProcedureControlValueBranches.txt

Purpose

The ProcedureControlValueBranches.txt input file is used to specify when quantitative control value sequence branching points will be generated and the specific control values to be used. For procedure step actions associated with a quantitative control input (e.g., opening a throttle valve to 10% open), two or more branches can be generated to explore the effect of variations in the control input. Each branch is assigned a specific control value and a conditional branch probability.

Input File Format

Each rule starts with one header line — procedure_name step_name action_name number_of_branches — followed by one control_value branch_probability pair per branch (matching the shipped BV4 file; the parser is token-based, so line breaks and other whitespace are interchangeable):

Procedure_Control_Value_Branches    number_of_items
procedure_name_1    step_name_1    action_name_1    number_of_branches_1
control_value_1     branch_probability_1
.
control_value_m     branch_probability_m
.
.
procedure_name_n    step_name_n    action_name_n    number_of_branches_n
control_value_1     branch_probability_1
.
control_value_m     branch_probability_m

Parameter Descriptions

Parameter	Type	Description	Example Value
number_of_items	Integer, > 0	Number of control value branching events in the file. Setting to 0 disables all branching without requiring deletion of entries.	2
procedure_name	String	Procedure associated with the branching rule. Must match a valid procedure_name in Procedures.txt.	FRG_H.1
step_name	String	Procedure step associated with the branching rule. Must match a valid step_name in Procedures.txt.	Step_1.2
action_name	String	Control panel action subject to value branching. Must match a control_name in ControlPanel.txt. If the control is not referenced by the specified step, no branches are generated (no error).	X_Watchdog_Timer
number_of_branches	Integer, ≥ 1	Number of control value branches to generate. With 1, no branching occurs — the single listed control value (with probability 1.0) is applied; the BV4 reference file uses this to pin specific control values.	3
control_value_i	Double, any	The control value applied to the action for branch i. Should be appropriate for the associated controller's range.	1200.0
branch_probability_i	Double, 0.0–1.0	Conditional probability assigned to branch i.	0.25

WARNING

All branch_probability values for a given branching rule must sum to exactly 1.0. If the sum does not equal 1.0, an error message will be generated. The branching rule will still be applied if activated, but results may not be physically meaningful.

TIP

Setting number_of_items to 0 disables all branching events without needing to delete entries. To activate only one branching event, move it to the top of the list and set number_of_items to 1. Only the first number_of_items entries are read — the BV4 reference file ships with a count of 0, so the example rules listed below its header are inert.

Execution

Each alternative defined here is opened as a child sequence that restarts from the branch point with that alternative applied. See How a Branch Alternative Executes.

Sample Input

Procedure_Control_Value_Branches    2
FRG_H.1    Step_1.2    X_Watchdog_Timer    3
1200.0    0.25
1800.0    0.50
2400.0    0.25
FRG_H.1    Step_7.5    X_Stm_Dump    2
0.07    0.5
0.25    0.5

Sample Explanation

• When action X_Watchdog_Timer is executed by procedure FRG_H.1, step Step_1.2, 3 control value branches are generated:

  • Branch 1: sets the watchdog timer to 1200.0 seconds with conditional probability 0.25
  • Branch 2: sets the watchdog timer to 1800.0 seconds with conditional probability 0.50
  • Branch 3: sets the watchdog timer to 2400.0 seconds with conditional probability 0.25

  The watchdog timer is used to trigger certain operator actions when the timer has elapsed, preventing excessive looping within a procedure.

• When action X_Stm_Dump is executed by procedure FRG_H.1, step Step_7.5, 2 control value branches are generated:

  • Branch 1: sets the steam dump valve opening position to 0.07 (7% open) with probability 0.5
  • Branch 2: sets the steam dump valve opening position to 0.25 (25% open) with probability 0.5