Accumulator Attributes - Metasys - LIT-1201793 - Software Application - Site Management Portal - 12.0.50

Metasys Site Management Portal Help

Brand
Metasys
Product name
Site Management Portal
Document type
User Guide
Document number
LIT-1201793
Version
12.0.50
Revision date
2023-06-02
Language
English

This object contains attributes common to many Metasys system objects. This section includes attributes of the Focus/Configuration tab, the Diagnostics tab (if applicable), and any other tab specific only to this object. See the Object and Feature Tabs section for information on the attributes that appear on the other tabs of this object (for example, the Hardware and Options tab appear on point objects).

Notes for Anti Spike:

  • Any mapper object used to deliver a raw count value to the Accumulator must provide an unreliable value during startup if the value was not updated from the field controller at the time it is read by the accumulator. For example, a LON counter mapped as an AI point object reports as unreliable until it reads a value from the field controller. If the LON counter is mapped as an AO point object, it reports as reliable even if the value is not initialized, causing improper values to be recorded at the accumulator. This may occur regardless of the value of Anti Spike.
  • Any mapper object used to deliver a raw count value to the accumulator must be allowed to count up without disruption from manual commands, schedules, interlocks, or any other function that may change its value outside the normal counting process. Any such changes may cause the Accumulator to record improper values regardless of the value of Anti Spike.
  • When replacing the input device, set Anti Spike to True before the replacement is brought online for the first time. This setting prevents the accumulator value from spiking upward due to an uncontrolled count value change at the input device. Failure to set Anti Spike to True can upset the accumulator value. You can use a manual preset to restore the correct value after the new device is online.
Note: In the Integration Type column, devices include: BACnet (Third-Party BACnet device), FEC (FEC family BACnet device), N2, and Other (for example, LonWorks, N1, VND, and XL5K). In the Notes column, letters indicate the following: B - Exposed as standard BACnet property, C - Configurable, D - Default Attribute for Display, N - Value Not Required, R - Affected by Extension’s Reliability, W - Writable.
Table 1. Accumulator Object Attributes - Focus/Configuration Tab

Attribute Name

Integration Type

Notes

Description

Anti Spike

N2

Other

C,W

When True, causes the object to use the first good input count value received after previously being unreliable as strictly an initial value. Any archived or last known value for input count is ignored. If the input device resets or loses power, uncontrolled changes to the input count value are filtered out and do not result in a spike in accumulator values. Use this setting in cases where the input device is not known to preserve its count value over a power loss (for example, in a LonWorks integration an LN-PRG20 GPI, and in an N2 integration a UNT).

When False, causes the object to use the first good input device count value received after previously being unreliable as a valid change from the archived or last known value for input count. This means the first good input device value is used to catch up on any counts that were missed while the input device was unable to communicate due to either an NAE restart or communication loss.

Do not set this value to False unless the input device is known to preserve its count value during a power loss (for example, in an N2 integration, an XTM-105 with a XPB-821 or in a LonWorks integration LN-PRG300-2, LNPRG400-2, LN-PTRG500-2, LN-PRG600, or in a vendor integration BTR Netcom GmbH device LC14 [Model # 11045013-US], an IDEC SX5L-SBCN081, or a WATANBE Electric Industry WRBC-DI16F-A002).

Device Type

All

C,N,W

Contains a description of the physical device connected to the object.

Display Precision

All

C,W

Determines how many decimal places to display in the Scaled Present Value.

Input Ref

Other

C

Identifies the attribute reference to the object property that is the pulse count input for the Accumulator object (for the Other integrations type: LonWorks , N1, VND, and XL5K, for example). This must be a continuously increasing positive numeric attribute of another object, such as the present value of a totalization extension to an analog meter.

Interface Value

N2

  Indicates current value from the hardware interface. This attribute is the same as input count, but is specific to the N2 accumulator.

Internal Units

All

C,W

Contains the engineering units for the Present Value, Value Set, Max Value, and Value Before Change attribute.

Intrinsic Alarming Defined

All

C,W

Indicates whether intrinsic alarming is enabled when the site is defined as a BACnet site. When intrinsic alarming is defined for accumulators on the MS/TP field bus, the pulse rate of the accumulated point can be monitored. For detailed information, see BACnet Intrinsic Alarming.

JCI Logging Object Reference

All

C,W

Indicates the object (Johnson Controls proprietary reference) that resides in the same device as the Accumulator object which, when it acquires Logging Record data from the Accumulator object, causes the Accumulator object to acquire, present, and store the Logging Record data (that is, snapshot) from the underlying system. When the object specified by the Logging Object Reference issues the Get Monitor Data command, the Logging Record is acquired and updated.

Limit Monitoring Interval

All

C,W

Specifies the monitoring period in seconds for determining the Pulse Rate. The Pulse Rate is the number of pulses received during the previous Limit Monitoring Interval period.

Logging Object Reference

All

 

Indicates the object (Johnson Controls proprietary reference) that resides in the same device as the Accumulator object which, when it acquires Logging Record data from the Accumulator object, causes the Accumulator object to acquire, present, and store the Logging Record data (that is, snapshot) from the underlying system. When the object specified by the Logging Object Reference issues the Get Monitor Data command, the Logging Record is acquired and updated.

Logging Record

All

 

Specifies a list of values to acquire, save, and return when read by other objects or devices.

  • Timestamp - Indicates the value of the Present Value attribute.timestamp - Indicates the local date and time when the data was acquired.
  • Present Value - Indicates the value of the Present Value attribute.
  • Accumulated Value - Indicates the short-term accumulated value of the counter. The algorithm used to calculate the accumulated value is a function of the value of accumulator status. If this is the initial read, the value returned is zero.
  • Accumulator Status - Indicates the reliability of the data in this list of values. The accumulator status values include:

    - Normal - Indicates that no event affecting the reliability of the data has occurred during the period from the preceding to the current qualified reads of the Logging Record attribute (Accumulated Value = current Present Value - previous Present Value).

    - Starting - Indicates that the data of the Logging Record attribute is either the first data acquired since startup by the object identified by Logging Object (that is, timestamp has no wildcard values) or that no data has been acquired since startup by the object identified by Logging Object (that is, timestamp has all wildcard values).

    - Recovered - Indicates that one or more writes to Value Set or changes to Value Before Change occurred since the Logging Record was acquired by the object identified by Logging Object (Accumulated Value = [current Present Value - Value Set] + [Value Before Change - previous Present Value]).

    - Abnormal - Indicates that the accumulation has been carried out, but some unrecoverable event such as the clock’s time changing a significant amount since the Logging Record was acquired by the object identified by Logging Object.

    - Failed - Indicates that the accumulation value is not reliable due to some problem.

Max Value

All

C,W

Indicates the maximum value allowed for the Present Value. The Present Value is not allowed to exceed this value, and wraps back to zero when this value is passed. Accumulation does not stop.

If the present value of the Accumulator object is being trended and its data is sent to the ADS repository, change this value to 32,767 so that the historian database (JCIHistorianDB) can properly store its value.

Out of Service

All

W

Periodic Update

FEC

N2

Other

C,W

This attribute only appears in the snapshot view of the mapper object and on the Engineering tab of the integration. This attribute applies to all integrations, except for BACnet integrations. Represents the time, in seconds, between successive COV messages issued by the local Accumulator object at a field device, or updates made to the Accumulator object on the UI.

The field device Accumulator object pushes its Present Value count up to the Supervisory controller through the COV mechanism. By requiring a minimum time between successive COVs, the Update Interval ensures that the integration does not get flooded with COVs from the Accumulator.

This attribute only appears in the snapshot view of the mapper object and on the Engineering tab of the integration.

Prescale

All

C,W

Indicates the coefficients used to convert the accumulated pulses into the Present Value. This attribute uses moduloDivide integer division (where 5/2 is 2). The algorithm used is:

Present Value = (prescale.multiplier x accumulated-pulses)/

prescale.moduloDivide.

Present Value

All

NW

Allows you to reset the Present Value. This command writes a supplied value to the Value Set attribute. The Present Value attribute then gains its value from the value written to the Value Set attribute. The Value Before Change takes on the previous value of the Present Value attribute (that is, the original value before the write processed), and the Value Change Time is set to the current date and time. This preserves the Present Value before the command took place. Use this command to change Present Value if the Accumulator object is in or out of service.

Reliability

All

W

Rollover Limit

N2

Other

C,W

Represents the actual rollover value of the input pulse counter. This attribute applies to N2 and Other Accumulators. This value is used to compute a change rate, which is added to the Accumulator property to calculate the Pulse Rate and Present Value.

You must set the rollover limit in the N2 accumulator to match the rollover limit of the N2 field device selected. For example, AHU or UNT devices have a rollover limit of 4,294,967,295. A DX-9100 CNT point has a rollover limit set by the GX-9100 configuration tool. An XT-9100 or XTM CNT point has a rollover limit set by the either the GX-9100 configuration tool or XTM configuration tool.

Scale

All

 

This BACnet property does not appear in a view in the Metasys system. Indicates the conversion factor to be multiplied with the value of the Present Value attribute to provide a Scaled Present Value in the units indicated by the Units attribute. By default, the Present Value and Scaled Present Value are equal. These values remain equal if you do not use the accumulator’s Scale attribute.

This attribute does not appear in a view; it is a BACnet property.

Scale As Float

All

C,N,W

Indicates the floating conversion factor to be multiplied with the value of the Present Value attribute to calculate the Scaled Present Value for the chosen units. If set to zero (the default value), the Scale As Integer value is used and Scale As Float is ignored.

Scale As Integer

All

C,N,W

Indicates the power of ten to be multiplied with the value of the Present Value attribute to get Scaled Present Value. This attribute only applies if Scale As Float is zero. For example, when Scale As Integer is set to two, the Present Value is multiplied by 100; while setting Scale As Integer to -1 multiplies the Present Value by 0.1. When zero (the default value), the Present Value and Scaled Present Value are equal (see Scaled Present Value).

Scaled Present Value

All

 

Indicates the value of the Present Value attribute conversion. The Present Value is multiplied by the Scale as Float value when that attribute contains a value (not zero). Otherwise, the Present Value is multiplied by 10 to the power of the Scale As Integer value (for example, if Scale As Integer is 3, it is multiplied by 1,000 and if Scale As Integer is -2, it is multiplied by 0.01). This is the actual value of the object.8

Status Flag

All

 

Indicates the general status of the Accumulator object in BACnet terms and contains four independent states. The states are:

In Alarm - False if the Event State attribute value is Normal; otherwise, the In Alarm flag is True.

Fault - True if the Reliability attribute is not reliable; otherwise, the Fault flag is False.

Overridden - Overridden flag is always False.

Out of Service - Out of Service flag is True if the Out of Service attribute value is True; otherwise, the Out of Service flag is False.

Units

All

C,W

Contains the engineering units for the Scaled Present Value attribute.

Use Remote Alarming

BACnet

C,W

When the attribute Intrinsic Alarming Defined is set to True, determines where alarms for the object originate. If the remote integrated object contains attributes for originating alarms, then Use Remote Alarming defaults to True, causing the local mapper object to accept alarms from the remote integrated object that are routed to the NxE. If the remote integrated object does not contain attributes for originating alarms, then Use Remote Alarming defaults to False causing the local mapper object to originate alarms. When Use Remote Alarming is false, any alarms from the remote integrated object are ignored at the NxE. If the value of Use Remote Alarming is changed, a restart of the NxE may be required to assure correct operation.

Value Before Change

All

  Indicates the Present Value prior to the last write to the Value Set property or Present Value command.

Value Change Time

All

  Indicates the time of the last change to the Value Before Change attribute or Preset Value command.

Value Set

All

W