Analog Input Attributes - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
13.1
Revision date
2019-12-04
Language
English

Table 1 describes the Analog Input object attributes. These attributes are displayed in alphabetical order. See Object Attributes in the Input and Output Objects section for descriptions of the data provided in this table. Unless otherwise stated, the attributes listed in this table appear in the Details dialog box (for example, the Present Value appears in the Control View below the module name in Simulation and Commissioning modes).

Table 1. Analog Input Attributes

Name

Type

Mode

Description

Anti Spike

Input

Configuration

Enables (True) or disables (False) the anti-spike filter. When this attribute is False, the sub-filter input passes directly to the sub-filter output.

For details on this attribute, see Table 2.

Application COV

Input

All Modes

Provides a change-of-value function for the application.

The Application COV is set to a non-zero value for setpoint inputs only (Network Sensor inputs excluded). For all other input types, the value is set to zero.

This attribute is used for inputs that change frequently, causing the application to run, which may increase COV messages on the MS/TP Field Bus.

COV Increment

Input

Configuration

Commissioning

Indicates the minimum change in Present Value (appears as O1) that triggers a new COV message. On the expiration of the Update Interval, the object compares the current Present Value with that of Present Value the last time a COV was sent.

Units: See Units.

This attribute is visible in an SAB device.

Description

Input

All Modes

Indicates the description provided for the object.

Device Type

Input

Configuration

Describes the physical network device to which the object is connected.

This attribute is visible in an SAB device.

Display Precision

Input

Configuration

Indicates the point at which value attributes are rounded for display (how many numbers following the decimal point appear).

Set Name: Display Precision

This attribute is visible in an SAB device.

Endpoint Tolerance

Input

Configuration

Defines a band outside the endpoints of the input signal for which the input is considered to equal the endpoint value. This input only applies to the user-defined linearization setup types.

For example, with a resistive setpoint adjustment, use this attribute to achieve the full range but to prevent the input from going unreliable unless the input truly fails (due to a wire break, for example).

Range: 0-100

Units: %

Field Offset

Input

Configuration

Specifies an offset applied to the hardware value to compensate for certain aspects of the system. This value is added to the hardware value before the object smooths out the data.

For example, you can enter a value for this attribute to compensate for wiring resistance in a temperature sensing application.

Field Units

Input

Configuration

Indicates the units for Field Offset, Input Range Low, Input Range High, Output Range Low, and Output Range High.

Set Name: Unit

This attribute is a calculated value (Output).

Filter Setup

Input

Configuration

Use to specify the mechanism that configures the AI filter parameters for your specific application. This attribute affects these attributes:
  • Time Constant
  • Anti Spike
  • Spike Fraction
  • Lowpass Filter Enable
  • Minus 20 dB Frequency
  • Update Interval
The tool does not enforce restrictions on these attributes. You are not prevented from editing these attributes, even though the Analog Input in the controller may ignore the value you enter.

The AI Filter Setup includes the following:

  • Process ID: Derives the Time Constant from an internal standards table. You cannot change any filter setup inputs.
  • Process Data: Ignores Process ID and allows you to configure Time Constant directly.
  • Monitor Only: Sets Time Constant to 900 seconds. You can modify Time Constant but no other filter setup inputs.
  • VAV Flow Control: Includes built-in handling of signal noise. The object disables Lowpass Filter Enable and ignores Process ID and Time Constant. You cannot change any filter setup inputs except Update Interval.
  • Custom: Use to configure all the filter setup points directly. The object ignores Process ID and Time Constant.

For details on this attribute, see Table 2.

Set Name: AI Filter Setup

Input Range High

Input

Configuration

Use to create a custom line of the input signal, along with Input Range Low, Output Range Low, and Output Range High. The Input Range Low and Input Range High default to the ends of the typical input range (0-10 Volts, 0-2,000 ohm, or 4-20 mA). Input Range Low must be less than Input Range High.

To define a line with a negative slope, set Output Range High to a value less than Output Range Low. The range of reliable values is based on the Min Value and Max Value. The Input Range Low, Input Range High, Output Range Low, and Output Range High attributes are used only to define the linear model.

If you choose a specific type of sensor, the input range high is defined already. In this case, the Input Range High attribute is not used, even though it does not appear dimmed.

Units: See Field Units.

Input Range Low

Input

Configuration

Use to create a custom line of the input signal, along with Input Range Low, Output Range Low, and Output Range High. The Input Range Low and Input Range High default to the ends of the typical input range (0-10 Volts, 0-2,000 ohm, or 4-20 mA). Input Range Low must be less than Input Range High.

To define a line with a negative slope, set Output Range High to a value less than Output Range Low. The range of reliable values is based on the Min Value and Max Value. The Input Range Low, Input Range High, Output Range Low, and Output Range High attributes are used only to define the linear model.

If you choose a specific type of sensor, the input range high is defined already. In this case, the Input Range High attribute is not used, even though it does not appear dimmed.

Units: See Field Units.

Lowpass Filter Enable

Input

Configuration

Enables (True) or disables (False) the low pass sub-filter. When this attribute is False, the sub-filter input passes directly to the sub-filter output.

For details on this attribute, see Table 2.

Max Value

Input

Configuration

Specifies the maximum value at which Present Value (appears as O1) can still be considered reliable. If the Present Value is higher than this value, the Reliability attribute goes to Unreliable High. Max Value must be more than Min Value.

This attribute resets to the default value if you edit the Setup or Units attributes.

Units: See Units.

Min Value

Input

Configuration

Specifies the minimum value at which Present Value (Appears as O1) can still be considered reliable. If the Present Value is lower than this value, the Reliability attribute goes to Unreliable Low. Min Value must be less than Max Value.

This attribute resets to the default value if you edit the Setup or Units attributes.

Units: See Units.

Minus 20 dB Frequency

Input

Configuration

Indicates the rejection frequency of the Bessel filter. A sinusoid signal at this frequency that passes through this filter is reduced ten times. An incorrect setting for this attribute can lead to instability of the Bessel filter.

The minimum value of this attribute is 0.01 and the maximum value is 3 (10* Hardware Period in seconds).

For details on this attribute, see Table 2.

Name

Input

All Modes

Indicates the name of the object.

Object Identifier

Input

All Modes

Indicates the instance number of the Object Type as exposed to the network. The Object Identifier must be unique within the host device. The Object Identifier is created after defining hardware in the Hardware Definition Wizard accessible from the Define Hardware button or Operations menu option.

The Object Identifier consists of the BACnet Class ID and the object’s Instance Number separated by a colon. For example, an Object Identifier of AV:10026 has a BACnet Class ID of AV and an Instance Number of 10026.

This attribute is visible in an SAB device.

Offline

Input

Commissioning

Indicates if the object is currently communicating with the network device.

This attribute is visible in an SAB device.

Offset

Input

Configuration

Specifies an offset applied to the hardware value to compensate for certain aspects of the system. This value is added to the input after the object smooths out the data.

Units: See Units.

This attribute is visible in an SAB device.

Note: In the CCT software, the Offset value for the NS Series CO2 Network Sensor Zone Quality (ZN-Q) AI is labeled ppm; however, as of Release 5.3, the Offset value for this device actually represents the local atmospheric pressure in hectopascals (hPa). Enter the Offset value only in units of hPa. The CCT software internally converts the entered hPa value into the correct Offset value. Refer to the NS Series CO2 Network Sensor Installation Instructions (Part No. 24-10424-6) for proper hPa values.

Out of Service

Input

Commissioning

Indicates whether the object is currently connected to the hardware or offline (out of service).

This attribute is visible in an SAB device.

Output Range High

Input

Configuration

Use to create a custom line of the input signal, along with Input Range Low, Input Range High, and Output Range Low. The Input Range Low and Input Range High default to the ends of the typical input range (0-10 Volts, 0-2,000 ohm, or 4-20 mA). Input Range Low must be less than Input Range High.

To define a line with a negative slope, set Output Range High to a value less than Output Range Low. The range of reliable values is based on the Min Value and Max Value. The Input Range Low, Input Range High, Output Range Low, and Output Range High attributes are used only to define the linear model.

If you choose a specific type of sensor, the Output Range High is defined already. In this case, the Output Range High attribute is not used, even though it does not appear dimmed.

Units: See Units.

Output Range Low

Input

Configuration

Use to create a custom line of the input signal, along with Input Range Low, Input Range High, and Output Range Low. The Input Range Low and Input Range High default to the ends of the typical input range (0-10 Volts, 0-2,000 ohm, or 4-20 mA). Input Range Low must be less than Input Range High.

To define a line with a negative slope, set Output Range High to a value less than Output Range Low. The range of reliable values is based on the Min Value and Max Value. The Input Range Low, Input Range High, Output Range Low, and Output Range High attributes are used only to define the linear model.

If you choose a specific type of sensor, the Output Range Low is defined already. In this case, the Output Range Low attribute is not used, even though it does not appear dimmed.

Units: See Units.

Present Value (Appears as O1)

Input

Simulation

Commissioning

Indicates the current value of the input.

This attribute changes when the following occurs:
  • if the Present Value attribute is changed by a user editing the attribute. This can be done only when Out of Service is False.
  • if the Present Value attribute is changed by a user commanding the attribute. This can be done only when Out of Service is True.
  • if changes occur in the hardware input (when the object has a live connection to the hardware)
  • if, on a transition from offline to a live connection to the hardware, the Present Value uses the last value reported from the hardware. If a value was never recorded before going offline, the value is not updated and Reliability goes to Connection Fail.
Set Name: States Text

This attribute is a generated value (Default Element), a calculated value (Output), and is visible in an SAB device.

Priority

Input

All Modes

Contains the current BACnet priority of the referenced object if it supports BACnet priorities.

Process ID

Input

Configuration

Specifies the process that the Analog Input object measures. If the Filter Setup is Process ID, the Process Identifier determines the filter setup. Otherwise, this attribute is ignored.

Set Name: Process ID

Reliability

Input

Simulation

Commissioning

Provides the following values to indicate whether or not the Present Value (appears as O1) is reliable:
  • Open Circuit: The hardware input is infinite for resistive measurements.
  • Short Circuit: The input is 0 for resistive measurements.
  • Unreliable Low: The Present Value is less than the Min Value.
  • Unreliable High: The Present Value is more than Max Value.
  • Connection Fail: The object fails to connect to the hardware.
  • Reliable: The object is none of the above.
If an Out of Service command is received, this attribute is Reliable. Only when the object is out of service can you write values to this attribute.

Set Name: Reliability

This attribute is a calculated value (Output) and is visible in an SAB device.

Source References

Input

Simulation

Commissioning

Indicates the array of attribute references for the sources. All references must be from a single object.

Spike Fraction

Input

Configuration

Defines the initial and minimum width of the anti-spike filter window in terms of AI range. The value should be less than 1.

For details on this attribute, see Table 2.

Status

Input

Simulation

Commissioning

Reflects the status of the object based on the Reliability attribute and the status of any commands.

Possible values for Analog Input objects are:
  • Out of Service: Out of Service is True.
  • Unreliable: Reliability is not reliable.
  • Normal: Neither of the above is correct.

Set Name: Status

This attribute is a calculated value (Output) and is visible in an SAB device.

Time Constant

Input

Configuration

Specifies the time it takes a first-order system to reach 63% of its final magnitude given a 100% step change. This setting affects the -20dB frequency of the Bessel filter. Small values can result in Bessel filter instability.

The minimum value of this attribute should be 10* Hardware Period in seconds. If Time Constant is less than the minimum value, set Lowpass Filter Enable to False.

For details on this attribute, see Table 2.

Units: Seconds

Units

Input

Configuration

Indicates the units of measurement for Present Value (appears as O1), Min Value, Max Value, and Offset.

Set Name: Unit

This attribute is visible in an SAB device.

Update Interval

Input

Configuration

Specifies the amount of time between evaluation of updates to Present Value (appears as O1), Reliability, and Status.

For details on this attribute, see Table 2.

Range: 0 - 4,294,967,295

Units: 100ths of seconds

Use COV Min Send Time

Input

Configuration

Configures the object to send COV messages on a periodic basis instead of on every change of value that exceeds the COV Increment. This attribute is typically set to True for objects with values that fluctuate greatly, such as air pressure, to decrease the number of COV messages. The change of value still must exceed the COV Increment to be reported.

The Min Send Time value is set at the supervisory controller on the Device object, and has a default of 15 seconds.

This attribute is visible in an SAB device.

Use Default if Not Reliable

Input

All Modes

Specifies the behavior when the Source is not reliable. If True, the Output is set to its Default Value whenever its Source is not reliable and its Reliability is marked as Reliable. If False, the Output maintains its last reliable value and its Reliability reflects the reason that the source is not reliable.

Table 2. Filter Setup Impact on Other Attributes

Filter Setup Input

Process ID

Process Data

Monitor Only

VAV Flow Control

Custom

Update Interval

Time Constant / 30

1 second 1

Defined by the user. 1

Anti Spike

True

Spike Fraction

0.02

Lowpass Filter Enable

True

False

Minus 20 dB Frequency

3.0 / Time Constant

N/A

Time Constant

Based on the Process ID.

Defined by the user. 1

900 seconds 1

N/A

1 Attributes in this table are updated by the controller to the specified values (online); however, you can modify them if desired.