N2 Binary Input/ BACnet Binary Input

Transcription

1 Object Dictionary 1 N2 Binary Input/ BACnet Binary Input Introduction Note: The Johnson Controls Binary Input object is considered a BACnet Binary Input object, because it supports BACnet functionality. In addition, this object has Johnson Controls proprietary attributes. The N2 Binary Input object s attributes represent the external, visible characteristics of a binary input. As a binary input, this object can be in either an Active or Inactive state. The Polarity attribute allows for normally open relays that are Active when energized and normally closed relays that are Inactive when energized. The N2 Binary Input object integrates N2 controllers into supervisory controllers, resulting in: a consistent interface to N2 point objects for all controller types, so they appear as a homogenous set to the user interface flexibility in point mapping support for all Metasys and Facilitator controllers. Refer to Table 1 in the Controller chapter (LIT ) of the Object Dictionary. For example, this object allows you to map a fan status into a supervisory controller. 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 N2 Binary Input/BACnet Binary Input Key Concepts BACnet Polarity Relationships The relationship between the Present Value of an object and the physical state of the object is determined by the Polarity attribute. Note: Table 1 describes this relationship as defined by BACnet standards. Johnson Controls Polarity is always Normal. Johnson Controls does not support changes to the Polarity attribute. Table 1: Polarity Relationships Present Value Polarity Physical State of the Hardware Input Inactive Normal Off or Inactive not running Active Normal On or Active running Inactive Reverse On or Active not running Active Reverse Off or Inactive running Physical State of the Monitored Device

3 Object Dictionary 3 Attributes Specific Attributes Table 2: Attribute Properties Table 2 lists the attributes specific to the N2 Binary Input object. The N2 Binary Input 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 M-Series N30 Default Value Options/Range Metasys Common Attributes See Table 1 in the Metasys Common Object chapter (LIT ). BACnet Required Attributes Event State Enumeration Normal Normal, Fault, Offnormal Object Identifier BACnet Object ID C Out of Service Boolean False False Polarity Enumeration W Normal Normal, Reverse See Normal Reverse Present Enumeration DNRW States Text attribute identifies Value 1 the enumeration set for this attribute. Status Flags Bit String False, False, False, False In Alarm, Fault, Overridden, Out of Service See BAC Status Flags * C - Configurable, D - Default Attribute, N - Value Not Required, R - Association to Reliability, W - Writable 1 If Out of Service is, this attribute is writable.

4 4 N2 Binary Input/BACnet Binary Input Attribute Name Data Type N30 M-Series N30 Default Value BACnet Optional Attributes Acked Bit String,, Transitions 2 Options/Range To-Offnormal, To-Fault, To-Normal See BAC Event Bits Active Text 3 String W Limit: 20 characters Alarm Value 2 Enumeration CW W Active Inactive, Active States Text attribute identifies the enumeration set for this attribute. Change of Unsigned W or greater State Count 4 Change of Date/Time W NONE_FFFF State Time 4 Device Type String CW W Null Limit: 20 characters Elapsed Active Time Unsigned Long W Null Units = seconds Event Enable 2 Bit String CW W,, To-Offnormal, To-Fault, To-Normal See BAC Event Bits Event Time Stamps 2 Array NONE_FFFF BACnetArray[3] of BACnet Time Stamp Inactive Text 3 String W Limit: 20 characters Notification Class 2 Unsigned Long CW W The BACnet Object Identifier of the Notification Class object used for routing Notify Type 2 Enumeration CW W Alarm Alarm, Event See BAC Notify Type Profile Name This BACnet optional attribute is not supported. * C - Configurable, W - Writable 2 These attributes are required if the object supports intrinsic reporting. 3 If either Inactive Text or Active Text is present, both are present. 4 If Change of State Time, Change of State Count, or Time of State Count Reset is present, all are present.

5 Object Dictionary 5 Attribute Name Data Type N30 M-Series N30 Default Value BACnet Optional Attributes Options/Range Reliability Enumeration Reliable No Fault Detected (Reliable), No Sensor, Open Loop, Shorted Loop, Unreliable Other See Reliability Enumeration Set in Time Delay 2 Unsigned Short CW W 0 Units = seconds Time of Date/Time W NONE_FFFF Active Time Reset 5 Time of State Count Reset 4 Date/Time W NONE_FFFF Intrinsic Alarming Net N2 Address Net Point Address Net Point Type Johnson Controls Proprietary Attributes Boolean C False False Byte C 0 Range: Unsigned Short C 0 Range: Enumeration C 0 See Network Point Type Offline Boolean False False Overridden Boolean R R False False States Text Enumeration CW W Off On See States Text in Trouble Boolean R R False False * C - Configurable, R - Association to Reliability, W - Writable 2 These attributes are required if the object supports intrinsic reporting. 4 If Change of State Time, Change of State Count, or Time of State Count Reset is present, all are present. 5 If either Elapsed Active Time or Time of Active Time Reset is present, both are present.

6 6 N2 Binary Input/BACnet Binary Input Attribute Definitions Table 3: Attribute Definitions Attribute Name Event State Object Identifier Out of Service Polarity Present Value Table 3 lists the definitions of the attributes specific to the N2 Binary Input object. Definition BACnet Required Attributes Indicates if an active event state associated with the object. If the object supports intrinsic reporting, this attribute indicates the event state of the object. If not, the attribute is Normal. Identifies the object with a unique numeric code. Indicates the offline/online state of the connected hardware. This attribute exists for compatibility with BACnet protocol and indicates whether the physical input that the object represents is in service. When out of service, the Present Value is not taken from the hardware. Indicates the relationship between the physical state of the input and the logical state represented by Present Value. If the Polarity attribute is Normal, then the Active state of the Present Value attribute is also the Active or On state of the physical input as long as Out of Service is False. If the Polarity attribute is Reverse, then the Active state of the Present Value attribute is in the Inactive or Off state of the physical input as long as Out of Service is False. If Out of Service is False for a constant physical input state, a change in the Polarity attribute produces a change in Present Value. If Out of Service is, the Polarity attribute has no effect on Present Value. The Johnson Controls Polarity attribute is always Normal. Indicates the current value of the binary input. Polarity determines the relationship between Present Value and the state of the input. When Out of Service is, Present Value is writable. Status Flags Contains four Boolean flags that indicate the general health of the object. Three of the four flags are associated with the values of other attributes within the same object. By reading these attributes, you can achieve a clearer picture of the object status. The four flags are: In Alarm - In Alarm flag is False (0) if the Event State property value is Normal; otherwise, the In Alarm flag is (1). Fault - Fault flag is (1) if the Reliability attribute is not reliable; otherwise, the Fault flag is False (0). Overridden - Overridden flag is Logical 1 if the Present Value is decoupled from the hardware output, because operator intervention provided a different value or local override is active. Out of Service - Out of Service flag is if the Out of Service attribute value is ; otherwise, the Out of Service flag is False.

7 Object Dictionary 7 Attribute Name Acked Transitions Active Text Alarm Value Change of State Count Change of State Time Device Type Description BACnet Optional Attributes Conveys three flags that separately indicate the receipt of acknowledgements for To-Offnormal, To-Fault, and To-Normal events. In Binary Input objects, transitions to High Limit and Low Limit Event States are considered to be Offnormal events. These flags clear upon the occurrence of the corresponding event and set under any of these conditions: upon receipt of the corresponding acknowledgement upon the occurrence of the event if the corresponding flag is not set in the Event Enable attribute (meaning event notifications are not generated for this condition and, thus, no acknowledgement is expected) upon the occurrence of the event if the corresponding flag is set in the Event Enable attribute and the corresponding flag in the Ack Required attribute of the Notification Class object implicitly referenced by the Notification Class attribute of this object is not set (meaning no acknowledgement is expected) This attribute is required if intrinsic reporting is supported by this object. Characterizes the intended effect of the Active state of Present Value from the viewpoint of the operator. The content of this string is a local matter but is intended to represent a readable description of the Active state. For example, if the physical input is a switch contact, then the Active Text attribute is assigned a value such as Fan 1 On. If either the Active Text or the Inactive Text attribute is present, both of them are present. Specifies the value that Present Value must reach before an event generates. If the object supports intrinsic reporting, this attribute is required. A To-Offnormal event generates under these conditions: The Present Value maintains the value specified by Alarm Value for a minimum period of time, specified in the Time Delay attribute. The To-Offnormal flag is enabled in the Event Enable attribute. Once equal to the Alarm Value, the Present Value must become not equal to Alarm Value before a To-Normal event is generated under these conditions: The Present Value remains not equal to the Alarm Value for a minimum period of time, specified by the Time Delay attribute. The To-Normal flag is enabled in the Event Enable attribute. Represents the number of times the Present Value attribute changes state since the Change of State Count attribute was most recently set to zero. A change of state is any event that alters Present Value. When Out of Service is False, a change to the Polarity attribute alters Present Value and is considered a change of state. When Out of Service is, changes to Polarity do not cause changes of state. If Change of State Time, Change of State Count, or Time of State Count Reset is present, all are present. Represents the date and time at which the most recent change of state occurred. A change of state is any event that alters the Present Value attribute. When Out of Service is False, a change to the Polarity attribute alters Present Value and is considered a change of state. When Out of Service is, changes to Polarity do not cause changes of state. If Change of State Time, Change of State Count, or Time Of State Count Reset is present, all are present. Contains a text description of the physical device connected to the binary input, usually describing the type of sensor. Elapsed Active Time Represents the accumulated number of seconds Present Value is Active since the Elapsed Active Time attribute was most recently set to zero. If either Elapsed Active Time or Time of Active Time Reset are present, all are present.

8 8 N2 Binary Input/BACnet Binary Input Attribute Name Event Enable Event Time Stamps Inactive Text Notification Class Description BACnet Optional Attributes Conveys three flags that separately enable and disable reporting of To-Offnormal, To-Fault, and To-Normal events. An unreliable condition generates a Fault event. This attribute is required if the object supports intrinsic reporting. Conveys the times of the last To-Offnormal, To-Fault, and To-Normal event notifications, respectively. Time or Date time stamps have FF in each octet. Sequence time stamps are 0 if no event notification of that type has been generated. If intrinsic reporting is supported by the object, this attribute is required. Characterizes the intended effect of the Inactive state of Present Value attribute from the viewpoint of the operator. The content of this string is a local matter, but it is intended to represent a readable description of the Inactive state. For example, if the physical input is connected to a switch contact, then the Inactive Text attribute is assigned a value such as Fan 1 Off. If either the Inactive Text or Active Text attribute is present, both are present. Specifies the notification class used when handling and generating event notifications for the object. This attribute implicitly refers to the Notification Class object that has a Notification Class attribute of the same value. This attribute is required if the object supports intrinsic reporting. Notify Type Conveys whether the notifications generated by the object are Events or Alarms. This attribute is required if the object supports intrinsic reporting. Reliability Indicates if the Present Value is unreliable and why. Any value defined in the Metasys Common Object (LIT ) can be written directly to this attribute. Any value written to the Reliability attribute remains until the next time the Present Value is written. Time Delay Specifies the minimum number of seconds that the Present Value must remain: outside the range defined by the High Limit and Low Limit attributes before a To-Offnormal event generates within the range defined by the High Limit and Low Limit attributes, including the Deadband attribute, before a To-Normal event generates This attribute is required for intrinsic alarming. Time of Active Time Reset Time of State Count Reset Represents the last date and time Elapsed Active Time set to a zero value. If either Elapsed Active Time or Time of Active Time Reset is present, all are present. Represents the date and time the Change of State Count attribute was most recently set to a zero value. If Change of State Time, Change of State Count, or Time of State Count Reset is present, all are present.

9 Object Dictionary 9 Attribute Name Intrinsic Alarming Description Johnson Controls Proprietary Attributes Enables the definition of the intrinsic alarm related attributes. Net N2 Address Indicates the actual controller N2 Address (1-254) as defined by switch settings on the controller. Net Point Address Indicates the network point address of the specified type (1-256). Net Point Type Offline Overridden States Text Trouble Indicates the point type in the controller. Indicates whether the object is online or offline as determined by the controller s offline condition. Shows the override state of the hardware (if supported by the hardware). Indicates the displayed strings for the Present Value. Indicates the trouble state of the hardware (if supported by the hardware). Commands The N2 Binary Input 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 Override Number of Parameters The value to be written to the Present Value Access Level Supervise Description Updates the Present Value at Command Priority Operator Override. Override Release Supervise Releases Command Priority Operator Override from Present Value. Enable Modify Allows distribution of Changes-of-Value and commanding. Disable Modify Prevents distribution of Changes-of-Value and commanding. Controls Group 507 E. Michigan Street P.O. Box 423 Milwaukee, WI Printed in U.S.A.