Schedule/BACnet Schedule

Transcription

1 Object Dictionary 1 Schedule/BACnet Schedule Introduction Note: The Johnson Controls Schedule object is considered a BACnet Schedule object because it supports BACnet functionality. In addition, this object has Johnson Controls proprietary attributes. The Schedule object updates attribute values of objects according to the time of day. These times can be specified for days of the and exception days. Exception days are days when you do not want the ly schedule to operate, such as holidays. They can be defined as specific dates, ranges of dates, or by reference to a Calendar object. A different set of activities can be defined to occur on the exception days as well. For information about the Calendar object, refer to the Calendar/BACnet Calendar chapter (LIT ) in the Object Dictionary. For example, this object allows you to schedule a fan to start every day at 7:00 A.M. and stop every day at 5:00 P.M., Monday through Friday. See the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) Standard for information on this object and the BACnet communication standard. May 1, 2002 Johnson Controls, Inc. Code No. LIT Software Release 5.1

2 2 Schedule/BACnet Schedule Key Concepts Schedules Exception Schedule Table 1: Exception Schedule Types Schedules are divided into days, of which there are two types: normal days within a and exception days. The scheduler exhibits restorative behavior in the event that the BACnet Device containing the schedule restarts or the time changes in the BACnet Device. The model for restoration assumes that each day s schedule is circular in nature. If the BACnet Device restarts after midnight but prior to the first time in the list of BACnet Time Values for that day, then the last value on the list for that day is used as the restoration value. If some other value is desired, then an explicit time of 00:00 is the first entry in the list. The Exception Schedule attribute contains scheduling information for special days of the year that take precedence over the normal (ly) schedule. Table 1 lists the types of exception schedules. Exception Type Calendar Ref Single Date Date Range Week and Day Description A reference to an existing Calendar object that determines the dates that the Exception Schedule is in effect. A valid Calendar object name must be entered. The date that the Exception Schedule is in effect instead of the current Schedule The range of dates that the Exception schedule is in effect instead of the current Schedule A recurring and day of the month that the Exception schedule is in effect instead of the current Schedule The Schedule object automatically deletes date or range type of exceptions that have expired more 31 days ago. All four exceptions also contain the times and corresponding values for the Schedule object to write to the scheduled objects on those exceptions. The exceptions are also prioritized (1...16), with 1 being the highest priority. If multiple exceptions apply for a given day, then the exception with highest priority will be in effect. If multiple exceptions apply for the current day and have the same priority, then the first of these in the list will be in effect. The /day selection can be used to identify particular days of the or months of the year, for example. The Calendar Ref selection can be used to identify an existing Calendar object that determines the dates that the Exception Schedule is in effect.

3 Object Dictionary 3 Dates Wildcard Date Fields Each date contains four fields: Month, Day of Month, Year, and Day of Week. These fields appear in the following format: <Day of Month> <Month> <Year> <Day of Week> The values of the Day of Month and Day of Week fields cannot contradict each other or the date is not valid. For example, a date of 10 Apr 2002 Tuesday does not schedule because April 10, 2002, is not a Tuesday. The values of a date range (start date, end date) must be in chronological order or the date range is not valid. For example, a date range with a start date of 30 Aug 2002 Friday and an end date of 30 Jun 2002 Sunday is invalid because August comes after June. Any unspecified date field is considered to be a wildcard date field. Single Date For a single date, a wildcard opens a particular field to the full range of possible values for that field. Table 2 describes the meaning of a wildcard in each of the four date fields. Table 2: Wildcard Date Field Meanings Unspecified Field Day of Month Month Year Day of Week Meaning Every day of the month, unless a particular day of the is specified by the Day of Week field Every month Every year Every day of the, unless a particular day of the month is specified by the Day of Month field Table 3 shows some sample wildcard dates and their meanings.

4 4 Schedule/BACnet Schedule Table 3: Sample Wildcard Dates Wildcard Date 01 * * Any day of 12 Apr * Any day of * Apr 2002 Any day of * * * Any day of Meaning The first day of every month, every year April 12 of every year Every day in April 2002 Every day * * * Friday Every Friday * * 2002 Friday Every Friday in 2002 * Apr 2002 Friday Every Friday in April of Apr 2002 Any day of * Indicates a blank field. Only on Friday, April 12, 2002 (same meaning as 4/12/02 Fri) Date Range If the same field is a wildcard in both the start date and end date, the range from start to end is infinite, except as limited by the other date fields. Table 4 shows some sample wildcard date ranges and their meanings. Note: The Day of Week field is considered only when it is specified for both the start date and the end date. Table 4: Sample Wildcard Date Ranges Start Date End Date Meaning * * * Wednesday * * * Friday Every Wednesday, Thursday, and Friday of every month, every year * * 2002 Wednesday * * 2002 Friday Every Wednesday, Thursday, and Friday of every month in 2002 * Jun 2002 Wednesday * Aug 2002 Friday Every Wednesday, Thursday, and Friday in June, July, and August in 2002 * Jun 2002 Any day of 30 Aug 2002 Any day of 10 * * Any day of * Aug 2002 Any day of * * * Any day of 12 * * Any day of Every day in June, July, and August in 2002 Every day after August 30, 2002 The tenth, eleventh, and twelfth days of every month, every year 04 Jul * Monday 04 Jul * Friday Every July 4 that is a Monday, Tuesday, Wednesday, Thursday, or Friday, every year * Indicates a blank field.

5 Object Dictionary 5 Week and Day The Week and Day selection identifies a month, a of the month, and a day of the. The of the month can be chosen as Any (every) of month, Days 1-7, Days 8-14, Days 15-21, Days 22-28, Days 29-31, and the Last seven days. Table 5 shows some sample wildcard and day exceptions. Table 5: Sample Wildcard Week and Days Wildcard Date Month Week of Month Day of Week Any Any of Any day of month Meaning Every day of the year Any Days 1-7 Monday Monday of the first of every month Jan Any of month Tuesday Every Tuesday in January Feb Days 8-14 Any day of Every day of the in the second of February Any Mar Any of month Any of month Wed Any day of Wednesday of every of every month Every day of every in March Any Days Any day of Every day of the third of every month Apr Days Thursday Thursday in the fourth of April Any Days Any day of Last three days of every month with 31 days Jun Last seven days Saturday Saturday in the last seven days of June Time Changes When a time change occurs or the supervisory controller restarts, the Schedule object attempts to reissue the last value that should have been scheduled. It searches backwards through the time and value pairs for the current day to find the last scheduled time. If no times are found from midnight to the current time, then the latest scheduled value is used. Daylight-saving time is also handled in this manner.

6 6 Schedule/BACnet Schedule Attributes Specific Attributes Table 6: Attribute Properties The attributes specific to the Schedule object are listed in Table 6. The Schedule object also has the attributes of the Metasys Common object. Refer to Table 1 in the Metasys Common Object chapter (LIT ) for details. Attribute Name Data Type N30 Flags* M-Series Flags* N30 Default Value Options/Range Metasys Common Attributes Effective Period List of Object Property References Object Identifier See Table 1 in the Metasys Common Object chapter (LIT ). Array of Dates BACnet Required Attributes CW [2] Items Begin date End date List CW [0] Items List of objects and their attributes that are to have their values updated. All objects in a List of Property References must reside in the same device. BACnet Object ID Present Value Numeric D Null Priority for Writing C Unsigned BACnet Optional Attributes Exception Schedule 1 List CW [0] Items Exception dates/days with a list of time pairs for each day Profile Name This BACnet optional attribute is not supported. Weekly Schedule 1 Objects in Device Calendar Device Perform Index Array of List of Structures Object Reference Object Reference Unsigned CW [7] Items Monday through Sunday with a list of time value pairs for each day Johnson Controls Proprietary Attributes CNW CNW Null Null Send OK Boolean True * C - Configurable, D - Default Attribute, N - Value Not Required, W - Writable 1 At least one of these attributes is required.

7 Object Dictionary 7 Attribute Definitions Table 7: Attribute Definitions Table 7 lists the definitions of the attributes specific to the Schedule object. Attribute Name Metasys Common Attributes Effective Period List of Object Property References Object Identifier Present Value Priority for Writing Exception Schedule Weekly Schedule Objects in Device Calendar Device Perform Index Send OK Definition See Table 2 in the Metasys Common Object chapter (LIT ). BACnet Required Attributes Defines the range of dates within which the Schedule object is active. By default, these dates are unspecified, causing the Schedule object to be active for all days. Wildcards may be used in the date fields. List of objects and their attributes that are to have their values updated. All objects in a List of Property References must reside in the same device. Identifies the object with a unique numeric code. Indicates the current value of the schedule (the value most recently written to a referenced object attribute of one member of the List of Object Property References). You can schedule analog, binary, and enumerated values. Defines the priority at which the referenced attributes are commanded. The priority defined here corresponds to the Priority parameter of the Write Property service. One is the highest priority and 16 is the lowest. BACnet Optional Attributes See Exception Schedule in the Key Concepts section for information. Contains one entry for each day of the - Monday, Tuesday,... Sunday. Each entry contains a list of the times and corresponding values for the Schedule object to write to the scheduled objects. The exception schedules override the times in this ly schedule. Johnson Controls Proprietary Attributes Indicates the object reference for the device that contains the scheduled objects referenced in the List Of Prop Refs attribute. If Null, the scheduled objects reside on the same device as the Schedule object. All scheduled objects must reside in the same device. Indicates the object reference for device that contains the Calendar objects referenced in the Exception Schedule attribute. If Null, the Calendar objects reside on the same device as the Schedule object. All Calendar objects referenced by one Schedule object must reside in the same device. Triggers the Optimal Start (OST) object when a change occurs to the times in effect for the current day. The OST object signs up for Changes of Value (COVs) to this attribute and the Schedule object sends a COV when the times change. This attribute identifies which element index of the Exception Schedule is in effect at the current day. Indicates if any of the write attribute messages sent at the last scheduled time failed.

8 8 Schedule/BACnet Schedule Commands The Schedule object supports the commands listed in Table 8. The order of the commands in the table reflects how the commands appear on the user interface. Table 8: Supported Commands Command Name Parameters Access Level Description Enable Modify Allows the Schedule object to resume normal scheduling operation. Disable Modify Halts all future scheduled times. Neither the ly nor the exception schedules will run again until the Schedule object is re-enabled. Controls Group 507 E. Michigan Street P.O. Box 423 Milwaukee, WI Printed in U.S.A.