Runtime Totalization. Introduction

Transcription

1 Object Dictionary 1 Runtime Totalization Introduction The Runtime Totalization object tracks the time that elapses while a designated input, such as a binary or multistate value, matches a specified state. Note: The Input of a Runtime Totalization object should refer to enumeration or Boolean-based attributes to perform as intended. Runtime Totalization objects referencing other attribute data types (for example, floating point) yield unusual results, though not necessarily unusable results. Neither the VT100, nor Project Builder, gives an error message when this object is attached to any attribute other than enumeration or Boolean-based attributes. These two essential parameters determine the Runtime Totalization object s mode of operation: the Input to be monitored the (state) that identifies active runtime Typical use of this object includes tracking the amount of time that a piece of equipment, such as a fan or a pump, is operational. This object also determines the amount of time a point is in alarm or the runtime of fixed loads (such as lighting) for energy consumption and tenant billback. May 1, 2002 Johnson Controls, Inc. Code No. LIT Software Release 5.1

2 2 Runtime Totalization Key Concepts Runtime Totalization Calculation and Example Table 1 contains the Runtime Totalization calculation and an example. Table 1: Runtime Totalization Calculation and Example Runtime Totalization Formula Example Note: Equation Present Value (Old) + TAn/(3600 x Scale Factor) = Present Value (New) 1.5 hours + 60 seconds/(3600 seconds/hour x 1) = 1.52 hours TAn represents the time the Input spends in the state.

3 Object Dictionary 3 Specific Table 2: Attribute Properties Attribute Name Metasys Common Display Precision Data Type The attributes specific to the Runtime Totalization object are listed in Table 2. The Runtime Totalization object also has the attributes of the Metasys Common object. Refer to Table 1 in the Metasys Common Object chapter (LIT ) for details. N30 Flags* N30 Default Value Options/Range See Table 1 in the Metasys Common Object chapter (LIT ). Enumeration CW 10ths See Display Precision Enumeration Set in Appendix A: Object Enumeration Sets (LIT ). Executing Enumeration Active Active Totalize Limit Inactive Input Attribute Present Value Double Float CDRW C Enumeration CW State 1 States Text attribute identifies the enumeration set for this attribute. Reset Boolean W False False True Rollover Boolean CW False False True Rollover Count Unsigned Long RW 0 Scalefactor Float CW 1.0 Minimum Value > 0 States Text Enumeration CW States See States Text in Appendix A: Object Enumeration Sets (LIT ). Totalize Limit Double Float CNW Hours Units attribute identifies the enumeration set for this attribute. Units Enumeration CW Hours See Units Enumeration Set in Appendix A: Object Enumeration Sets (LIT ). * C - Configurable, D - Default Attribute, N - Value Not Required, R - Association to Reliability, W - Writable

4 4 Runtime Totalization Attribute Definitions Table 3: Attribute Definitions Table 3 lists the definitions for the attributes specific to the Runtime Totalization object. Attribute Name Metasys Common Display Precision Executing Input Present Value Reset Rollover Rollover Count Scalefactor States Text Status Totalize Limit Units Definition See Table 2 in the Metasys Common Object chapter (LIT ) and Status in this table. This attribute indicates the rounded position and the number of decimal places to display for this object. The execution status of this object: Active - The object is calculating and has not reached the Totalize Limit. Totalize Limit - The object has reached the limit and has stopped calculating because Roll Over is set to False. Inactive - The object is unreliable or disabled and is not calculating. Specifies the object and attribute totalized by this object. If this attribute is unreliable or changes from the (state) to another state, totalization is temporarily suspended. Represents the current value of the object. Writing to this attribute forces object into reset condition. Defines the value that is processed for totalization by the object as defined in the Input attribute. Writing to this attribute forces object into reset condition. Forces the object into a reset condition. (Terminates any ongoing calculations, restores the Present Value to initial state, and for each triggerable attribute, forces a Change of Value [COV] report.) Defines the special action the totalization object must take when the Present Value reaches the Totalize Limit value. If the Rollover attribute is set to False, the Runtime Totalization object ceases further operation when the Present Value equals or exceeds the Totalize Limit value. If it is True, it resets the present Value to 0.0 and resumes a new cycle of totalization. Writing this attribute after the Present Value equals or exceeds the totalize limit value (if defined) forces the object into a reset condition. When the Rollover attribute is True, this value is incremented each time Present Value reaches a value equal to or greater than the Totalize limit value. Indicates the value used to scale the totalized value to either a larger or smaller value than would otherwise result. Writing to this attribute forces the object into reset condition. Indicates the displayed strings for the Present Value. The Metasys Common Object chapter (LIT ) details this attribute. A list of relevant states follows (listed in hierarchical order from highest to lowest): Disabled Enabled attribute value is False. Unreliable Normal Reliability attribute is not reliable. Expected operating condition Defines a threshold value the Present Value must meet or exceed for the totalization object to take special action. When the Rollover attribute is set to False, the totalization process ceases further operation. When it is set to True, Present Value is cleared to 0, and the totalization process starts over. Writing this attribute after the Present Value equals or exceeds the totalize limit value (if defined) forces the object into a reset condition. Indicates the measurement units of this object.

5 Object Dictionary 5 Commands The Runtime Totalization object supports the commands listed in Table 4. The order of the commands in the table reflects how the commands appear on the user interface. Table 4: Supported Commands Command Name Parameters Access Level Description Reset Supervise Terminates any ongoing calculations, restores the present value to its initial state, creates a reset date and time stamp, and, for each triggerable attribute, forces a Change of Value (COV) report. Enable Modify Forces a Reset on the Runtime Totalization object and returns it to normal operation. Disable Modify Locks out all outputs and prevents functionality of the Runtime Totalization object. Temporarily suspends totalization. Controls Group 507 E. Michigan Street P.O. Box 423 Milwaukee, WI Printed in U.S.A.