Working with BACnet Group Objects

Transcription

1 N30 Supervisory Controller User s Manual 33-1 Chapter 33 Working with BACnet Group Objects Introduction Note: Do not confuse the BACnet Group object with the Johnson Controls Group object. For information on the Group object, refer to the Working with Group Objects chapter (LIT ) of the N30 Supervisory Controller User s Manual or the Group chapter (LIT ) of the Object Dictionary. The BACnet Group object provides the user with the ability to customize the organization of objects within the site. The BACnet Group object simplifies the exchange of information between objects by calling all members of the group at once. A group consists of any combination of object types. For example, you can use the BACnet Group object to monitor the temperature in different rooms throughout a floor of a building. This chapter describes the difference between BACnet Group objects and Group objects and how to: add a BACnet Group object edit a BACnet Group object delete a BACnet Group object Note: The BACnet Group object is not VT100 configurable. You must use Project Builder to configure the BACnet Group object. See the American Society of Heating, Refrigerating, and Air-conditioning Engineers (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 33-2 Working with BACnet Group Objects Key Concepts BACnet Group Object vs Johnson Controls Proprietary Group Object Differences between BACnet Group objects and Johnson Control Proprietary Group objects are: BACnet Group objects are compliant with the BACnet protocol, while Group objects are not. BACnet Group objects reference any object except another BACnet Group object as long as all members of the group reside in the same device that maintains the BACnet Group object. Group objects can reference other Group objects and objects that do not reside in the same device. BACnet Group objects have no limit to the number of members in a group, and each object member within the group includes one or more of its attributes. The Group object can hold up to 75 group members. BACnet Group objects list multiple attributes of the group members while the Group objects only list the Present Value of the group members. For information on the Group object, refer to the Working with Group Objects chapter (LIT ) of the N30 Supervisory Controller User s Manual or the Group chapter (LIT ) of the Object Dictionary. Attributes The values of an object s attributes determine how the object operates. The BACnet Group object attributes are described below. For additional information about the BACnet Group object and its attributes, refer to the BACnet Group chapter (LIT ) of the Object Dictionary. Object Name Identifies the object on the user interface. Description Provides optional information to further describe the object.

3 N30 Supervisory Controller User s Manual 33-3 Table 33-1: Input Reference Syntax Object Type Indicates membership in a particular object type class. In this case, the object type is BACnet Group. Object Identifier Identifies the object with a unique code. List of Group Members Contains the references (Input References) that define the members of the group. These group members are referenced during a transaction. The List of Group Members consists of two parts: Object Identifier (Object ID) List of Property References (Attribute or Attribute with Array) In M-View, the Object Identifier and the List of Property References form the Input Reference. The Input Reference uses the syntax shown in Table Nesting is not allowed and the List of Group Members cannot refer to the Present Value property of the BACnet Group object. Refer to Editing a BACnet Group Object in the Detailed Procedures to add and delete the Input Reference elements of this attribute. Input Reference Type Format Example Full Reference with Array Index Full Reference without Array Index Functional Name with Array Index Functional Name without Array Index BACnet Syntax with Array Index BACnet Syntax without Array Index <Device ID>.<Object ID>.<Attribute(Array)> <Device ID>.<Object ID>.<Attribute> <Object ID>.<Attribute (Array)> <Object ID>.<Attribute> #<Device ID>:(#<class>:<instance>).#<Attribute (Array)> B7F3N01.Programming.AV{1}.Priority Array[8] B7F3N01.Programming.AV{1}.Present Value Test AV.Priority Array[8] Test AV.Present Value #32:(#2:65001).#87[8] #<Device ID>:(#<class>:<instance>).#<Attribute> #32:(#2:65001).#85

4 33-4 Working with BACnet Group Objects Detailed Procedures Notes: Adding a BACnet Group Object Editing a BACnet Group Object The BACnet Group object is not VT100 configurable. You must use Project Builder to configure the BACnet Group object. Before performing the following procedures, start Project Builder and open or create the project in which you want to add a BACnet Group object. Refer to the Getting Started chapter (LIT ) of Project Builder User s Guide. Note: You must use Project Builder to add the BACnet Group object. For instructions on adding a BACnet Group object, refer to the Working with Objects and the M-View Screen chapter (LIT ) of Project Builder User s Guide. Note: Figure 33-1 and Figure 33-2 show a Group object configured to monitor the objects used by the Optimal Start (OST) object that controls the heating and cooling of a zone in a building for the month of December. To edit a BACnet Group object: 1. Double-click the row head of the BACnet Group object or, with the BACnet Group object selected, select Edit Object on the Edit menu. The M-View Configuration dialog box appears (Figure 33-1).

5 N30 Supervisory Controller User s Manual 33-5 Figure 33-1: M-View Configuration Dialog Box 2. Edit the parameters using Table Refer to the BACnet Group chapter (LIT ) of the Object Dictionary. Note: Clicking Cancel returns you to Project Builder without saving your changes. Table 33-2: Editing BACnet Group Object Attributes To Edit This Attribute Object Name Description Object Type Object Category Do This Type a name for this BACnet Group object (optional). Type a description for this BACnet Group object (optional). This attribute cannot be edited. Object Type is BACnet Group. Select the desired category for this BACnet Group object. Default is HVAC. 3. Click the List Elements button. The List Of Group Members dialog box appears (Figure 33-2).

6 33-6 Working with BACnet Group Objects Figure 33-2: List Of Group Members Dialog Box - Optimal Start (OST) Example Notes: If there are no Input References defined, the left side of the screen is blank. Clicking Cancel or Back returns you to the M-View Configuration dialog box without saving your changes. In Figure 33-2, Input Reference 3 is a reference to the Present Value of an Analog Value object s Outdoor Air Temperature used by the OST object in its calculations. 4. To add an Input Reference, click Add and type the Input Reference in the box according to the syntax in Table Repeat this step if you want to add more Input References. Note: You must define at least one input reference to download the database to an N30 and save your changes. 5. To delete an Input Reference, select the Input Reference box you want to delete and click Delete. Repeat this step if you want to delete more Input References. 6. Click Done to save your changes and return to the M-View Configuration dialog box. 7. Click OK to save your changes and return to Project Builder. Note: To view the Present Value of the BACnet Group object, enter online mode and use the M-Inspector feature.

7 N30 Supervisory Controller User s Manual 33-7 Deleting a BACnet Group Object You can delete a BACnet Group object using Project Builder or the VT100. Using Project Builder For instructions on deleting a BACnet Group object using Project Builder, refer to the Working with Objects and the M-View Screen chapter (LIT ) of Project Builder User s Guide. Using the VT100 To delete a BACnet Group object using the VT100: 1. Browse to and highlight the BACnet Group object. 2. Press Enter to open the object. 3. Press the Delete key. 4. Press the Tab key to confirm the deletion. Controls Group 507 E. Michigan Street P.O. Box 423 Milwaukee, WI Printed in U.S.A.