Historian Tags Reference

Define tags to be historized.

Reference → Modules →  Historian → UI → Tags | Tables | Storage | Monitor

Historian Tags (Reference) define the mapping between data points and their archival storage configuration within the ProView DS Historian module. Historian Tags are the fundamental configuration objects that:

  • Link tags to historian tables for organized storage
  • Define data collection parameters
  • Configure deadband and deviation settings
  • Support both internal tags and external assets
  • Enable template-based archiving

Each Historian Tag represents a data point tracked and stored over time with specific collection rules.

Configuration Properties

TagNameUnique identifier of tag to archiveYes-
HistorianTableTarget table for data storageYes-
DeadBandMinimum change in units for SaveOnChangeNo0
DeviationOverride for TimeDeadBand intervalNo0
RateOfChangeUnits/second threshold for storageNo0
DeviationDeadBandTypeAbsolute or Percentual calculationNoAbsolute

Creating Historian Tags

Prerequisites

  • Configured HistorianTable (or use default Table1)
  • Tags defined in Unified Namespace
  • Understanding of collection requirements

Configuration Steps

  1. Navigate to Historian → Historian Tags
  2. Enter TagName or select from list
  3. Configure deadband parameters:
    • DeadBand for value changes
    • Deviation for time overrides
    • RateOfChange for velocity triggers
  4. Select DeviationDeadBandType
  5. Choose target HistorianTable

Deadband Configuration

DeadBand (Value Change)

Minimum absolute change required for storage:

  • Applied with SaveOnChange trigger
  • Reduces database writes
  • Filters noise and minor fluctuations

Example:

TagName: Tank.Level
DeadBand: 0.5
// Only stores when level changes by ±0.5 units

Deviation (Time Override)

Overrides TimeDeadBand interval when exceeded:

  • Forces storage regardless of time interval
  • Captures significant changes immediately
  • Works with TimeDeadBand configuration

Example:

TagName: Reactor.Temperature  
Deviation: 5.0
TimeDeadBand: 60 seconds
// Stores every 60s OR when temp changes by ±5°

RateOfChange (Velocity)

Triggers on rapid value changes:

  • Measured in units per second
  • Detects process upsets
  • Overrides time intervals

Example:

TagName: Pressure.Line1
RateOfChange: 10
// Stores when pressure changes >10 PSI/second

DeviationDeadBandType

Absolute

Fixed unit threshold:

Current Value: 100
Deviation: 5
Triggers at: <95 or >105

Percentual

Percentage of current value:

Current Value: 100
Deviation: 5 (%)
Triggers at: <95 or >105

Current Value: 200
Deviation: 5 (%)
Triggers at: <190 or >210


UserType Tags (Template Tags)

Archive entire templates or specific properties:

Full Template

TagName: Pump1
// Archives all properties of Pump1 template

Specific Property

TagName: Pump1.Motor.Current
// Archives only motor current property

Multiple Instances

When using template arrays:

TagName: Pumps[1].Flow
TagName: Pumps[2].Flow
// Individual configuration per instance

HistorianTable Assignment

Grouping Strategy

Assign tags to tables based on:

  • Update frequency
  • Process relationships
  • Data types
  • Storage requirements

Best Practices

< 1 secondHighSpeed
1-10 secondsProcess
10-60 secondsSupervisory
> 60 secondsSlowData

Runtime Behavior

SaveOnChange Mode

Tag changes → Check DeadBand → Store if exceeded

Trigger Mode

Trigger fires → Store all table tags → Apply timestamp

TimeDeadBand Mode

Timer expires → Check Deviation/RateOfChange → Store if exceeded OR timer

Performance Optimization

DeadBand Settings

  • Analog signals: 0.1-1% of range
  • Digital signals: Usually 0 (all changes)
  • Calculated values: Based on significance

Table Organization

  • Group similar update rates
  • Separate critical from non-critical
  • Consider query patterns
  • Balance table sizes

Storage Efficiency

  • Use Normalized tables for sparse data
  • Standard tables for synchronized data
  • Enable compression where supported

Common Configurations

Temperature Monitoring

TagName: Furnace.Temperature
DeadBand: 0.5
Deviation: 10
RateOfChange: 5
DeviationDeadBandType: Absolute
HistorianTable: ProcessData

Level Tracking

TagName: Tank.Level
DeadBand: 0.1
Deviation: 5
DeviationDeadBandType: Percentual
HistorianTable: TankFarm

Discrete Events

TagName: Pump.Status
DeadBand: 0
HistorianTable: Events
// Captures all state changes

Troubleshooting

Data not archiving:

  • Verify tag name spelling
  • Check HistorianTable is active
  • Review deadband settings
  • Confirm tag has valid quality

Excessive storage:

  • Increase deadband values
  • Review deviation settings
  • Check for oscillating tags
  • Enable time deadband

Missing rapid changes:

  • Decrease RateOfChange threshold
  • Reduce deviation value
  • Check scan rates
  • Verify trigger configuration

Template tags not working:

  • Confirm template structure
  • Check property paths
  • Verify array indices
  • Review instance names

Best Practices Checklist

  • Set appropriate deadbands - Balance detail vs storage
  • Group related tags - Same table for correlated data
  • Document settings - Record why values chosen
  • Test configurations - Verify before production
  • Monitor performance - Track storage growth
  • Use templates efficiently - Archive needed properties only
  • Plan for maintenance - Consider future adjustments