BACnet Clarification for Date Entries - Metasys - LIT-12011942 - Software Application - ODS Server - 10.1

Metasys Open Data Server Help

Brand
Metasys
Product name
ODS Server
Document type
User Guide
Document number
LIT-12011942
Version
10.1
Revision date
2019-10-14
Language
English

ASHRAE has published a BACnet addendum 135-2008H Part 8 to clarify what is allowed in the format of calendar entries for single dates and range of date formats in the Calendar object and the exception schedule (the dates you want the Schedule to operate in a special way, such as holidays). If the BACnet Compatible attribute in the Device object is set to True, these BACnet rules are enforced.

For a Calendar object Date entry, the entry can be either a specific date or a date pattern:

  • a specific date has all fields filled with specific values, including the Day of Week
  • a date pattern has some fields filled with odd, even, last, or the any wildcard

For a Calendar object Date Range entry, the new rules restrict each part (start date and end date) to be one of the following:

  • a fully specified date (all fields defined)
  • a completely unspecified date (no fields defined - all fields use the any wildcards, which means the Start Date is immediate or the End Date is never)
Note: For Date Range, the Metasys system currently allows partial wildcard fields for the start and end dates, which leads to unpredictable operation in some cases. Therefore, to avoid undesired results, do not use partial wildcard fields for the start date or end date. The examples in Table 1 illustrate valid date range entries and their meanings. The examples in Table 2 show three invalid date range entries. Be sure to follow the new BACnet rules to avoid these kinds of entries.
Table 1. Valid Wildcard Date Range Examples
Example

Duration

Month

Day

Year

Day of Week

Meaning

1

From

Aug

30

2015

Sunday

Starts on Sunday, August 30, 2015 and continues indefinitely.

To

any

any

any

any

2

From

any

any

any

any

Continues until Saturday, July 4, 2015

To

Jul

4

2015

Saturday

3

From

Jan

1

2015

Thursday

Starts on Thursday, January 1, 2015 and ends on Thursday, April 30, 2015

To

April

30

2015

Thursday

Table 2. Invalid Wildcard Date Range Examples
Example

Duration

Month

Day

Year

Day of Week

1

From

any

3

any

any

To

any

6

any

any

2

From

any

any

any

Saturday

To

any

any

any

Sunday

3

From

May

any

2014

Saturday

To

September

any

2014

Sunday

Note: No partial wildcard (any) fields for start date or end date are allowed in order to eliminate cases that could not be clearly interpreted and implemented.