Tag Management

Managing data points, polling configuration, and tag metadata in DataForeman

Tag Management

Tags are the core data points in DataForeman that represent values collected from industrial devices. This guide covers browsing, saving, configuring, and managing tags across different protocols.

Tag Management Interface

Overview

Tag management in DataForeman allows you to:

  • Browse device tag structures through protocol-specific browsers
  • Select and save tags for continuous monitoring
  • Configure polling rates and change detection
  • Organize tags with metadata, units, and descriptions
  • Import/Export tag configurations for backup and bulk editing

Accessing Tag Management

  1. Navigate to Connectivity from the main menu
  2. Click the TAGS tab
  3. Select your protocol (OPC UA, Siemens S7, or EtherNet/IP)
  4. Choose your connection from the dropdown

Protocol-Specific Tag Browsers

OPC UA Tag Browser

The OPC UA tag browser allows hierarchical navigation through the server’s address space:

Features:

  • Tree-based node navigation with breadcrumb trail
  • Folder and variable node icons
  • Real-time browsing of OPC UA server structure
  • Automatic data type detection
  • Multi-select tag saving

Workflow:

  1. Select your OPC UA connection
  2. Ensure connection is started (enabled) on the Devices tab
  3. Browse the node tree by clicking on folders
  4. Select variables (data points) using checkboxes
  5. Choose a poll group for the selected tags
  6. Click Save Selected Tags to add them to monitoring

Troubleshooting:

  • If browsing fails, verify the connection is started on the Devices tab
  • Check that the OPC UA server is reachable
  • Review security settings if authentication issues occur

Siemens S7 Tag Entry

For Siemens S7 PLCs, tags are entered manually using PLC addressing:

Supported Address Formats:

  • Data blocks: DB1.DBX0.0, DB1.DBW2, DB1.DBD4
  • Inputs: I0.0, IW2, ID4
  • Outputs: Q0.0, QW2, QD4
  • Markers: M0.0, MW2, MD4

Data Types:

  • Bit values (X): Boolean
  • Byte/Word/DWord (B/W/D): Integer types
  • Real (R): Floating point

EtherNet/IP Tag Browser

EtherNet/IP provides multiple discovery methods:

Discovery Options:

  1. Auto-discover tags from controller
  2. Enter tag names manually
  3. Import from CSV for bulk configuration

Tag Path Format:

  • Controller tags: TagName
  • Structure members: StructTag.Member
  • Array elements: ArrayTag[0]

Saved Tags List

The saved tags table displays all configured tags for monitoring:

Columns:

  • Tag ID: Unique identifier
  • Name: Tag display name
  • Type: Data type (Int32, Double, Boolean, etc.)
  • Status: Active, Inactive, or Deleting
  • Poll Group: Assigned polling rate
  • Unit: Engineering unit (optional)

Actions:

  • Search: Filter tags by name or ID
  • Select multiple: Bulk operations (delete, change poll group)
  • View deleted: Toggle to show recently deleted tags
  • Import/Export: CSV operations for Excel editing

Poll Groups (Sampling Rates)

Poll groups define how frequently tags are read from devices. Each tag must be assigned to a poll group.

Available Poll Groups

Group ID Name Rate Use Case
1 Ultra Fast 50ms Critical real-time control
2 Very Fast 100ms High-speed monitoring
3 Fast 250ms Fast process control
4 Normal 500ms Standard monitoring
5 Standard 1000ms Default polling (1 second)
6 Slow 2000ms Slow changing values
7 Very Slow 5000ms Infrequent updates
8 Diagnostic 10000ms Equipment diagnostics
9 Hourly 60000ms Hourly statistics
10 Custom 30000ms Custom/flexible rate

Best Practices:

  • Use faster rates (1-4) only for critical tags
  • Default to Standard (5) for most applications
  • Slower rates reduce network traffic and database load
  • Group similar update frequencies together

Changing Poll Groups

For new tags:

  • Select poll group before saving tags

For existing tags:

  1. Select tags in the Saved Tags list
  2. Click the poll group dropdown above the table
  3. Choose new poll group
  4. Click Update to apply

Write-on-Change Configuration

Write-on-change prevents saving unchanged values to the database, reducing storage and improving performance.

Configuration Options

On Change Enabled: Enable/disable change detection for tag

  • Default: Enabled for numeric tags
  • Recommended: Keep enabled unless you need every reading

Deadband Value: Minimum change required to save

  • Absolute mode: Value must change by at least this amount
    • Example: Deadband of 1.0 means value must change by ±1.0
  • Percent mode: Value must change by this percentage
    • Example: 5% means value must change by ±5% of current value

Heartbeat: Maximum time between writes (milliseconds)

  • Default: 60000ms (1 minute)
  • Forces a write even if value hasn’t changed enough
  • Ensures data isn’t lost during periods of small changes

Example Configurations:

Scenario Deadband Type Heartbeat
Temperature (±0.5°C) 0.5 Absolute 60000ms
Pressure (±2%) 2.0 Percent 30000ms
Boolean values 0.0 Absolute 5000ms
High precision 0.01 Absolute 10000ms

Tag Metadata

Each tag can have additional metadata for organization and context:

Available Fields:

  • Name: Display name (auto-filled from device)
  • Description: Custom notes about the tag
  • Data Type: Automatically detected from device
  • Unit of Measure: Engineering unit (°C, PSI, RPM, etc.)
  • Custom metadata: JSON field for additional properties

Editing Metadata:

  1. Click on a tag row in the Saved Tags list
  2. Edit fields in the detail panel
  3. Click Save to update

Units of Measure

Assign engineering units to tags for proper display in charts and dashboards.

Common Units:

  • Temperature: °C, °F, K
  • Pressure: PSI, bar, Pa, kPa
  • Flow: L/min, GPM, m³/h
  • Speed: RPM, m/s, km/h
  • Power: W, kW, HP

Adding Units:

  1. Navigate to Settings → Units
  2. Click Add Unit
  3. Enter symbol and description
  4. Assign to tags as needed

CSV Import/Export

Bulk manage tags using Excel or other spreadsheet applications.

Exporting Tags

  1. Click CSV Import/Export button
  2. Click Export CSV
  3. Open in Excel to edit

Export includes:

  • Tag ID, Name, Path
  • Data Type
  • Poll Group
  • Unit
  • On-change configuration
  • Description and metadata

Importing Tags

  1. Edit your CSV file in Excel
  2. Keep Tag ID column to update existing tags
  3. Remove Tag ID to create new tags
  4. Click Import CSV and select file
  5. Review preview before confirming

Import Rules:

  • Existing tags (with Tag ID) will be updated
  • New rows (no Tag ID) create new tags
  • Invalid data types are rejected
  • Duplicate tag paths are skipped

Required Columns:

  • tag_path: Device address (OPC UA NodeId, S7 address, etc.)
  • tag_name: Display name
  • data_type: Valid data type for protocol

Optional Columns:

  • poll_group_id: 1-10
  • unit: Unit symbol
  • description: Custom notes
  • on_change_enabled: true/false
  • on_change_deadband: Numeric value
  • on_change_deadband_type: absolute/percent
  • on_change_heartbeat_ms: Milliseconds

Deleting Tags

Single Tag Deletion:

  1. Select tag in Saved Tags list
  2. Click delete icon (trash can)
  3. Confirm deletion

Bulk Deletion:

  1. Select multiple tags using checkboxes
  2. Click Delete Selected
  3. Confirm batch deletion

Deletion Process:

  • Tags are marked as “deleting” status
  • Background job removes historical data
  • Tag is fully removed after data purge completes
  • Large datasets may take time to delete

Note: Deleted tags can be viewed temporarily by toggling “Show Deleted” filter.

Tag Status

Tags can have different statuses indicating their operational state:

  • Active: Tag is being polled and data is collected
  • Inactive: Tag is saved but not currently monitored
  • Pending Delete: Marked for deletion
  • Deleting: Background deletion in progress
  • Deleted: Fully removed from system

Best Practices

  1. Organize by Function: Use naming conventions to group related tags
  2. Appropriate Poll Rates: Don’t over-poll slow-changing values
  3. Enable Change Detection: Reduce database growth with deadbands
  4. Document Tags: Add descriptions for critical or complex tags
  5. Use Units: Always assign engineering units for clarity
  6. Regular Backups: Export tag configurations periodically
  7. Test Before Production: Verify tag addressing in test environment

Troubleshooting

Tags Not Updating

  1. Check connection status on Devices tab
  2. Verify tag path/address is correct
  3. Ensure poll group is active
  4. Review device connectivity logs

Browse Fails for OPC UA

  1. Start the connection on Devices tab
  2. Check OPC UA server is reachable
  3. Verify security mode and credentials
  4. Review error messages in diagnostic logs

Import Fails

  1. Verify CSV format matches export structure
  2. Check for invalid data types
  3. Ensure tag paths are valid for protocol
  4. Review import error messages

High Database Growth

  1. Enable write-on-change for numeric tags
  2. Increase deadband values
  3. Use slower poll groups where appropriate
  4. Implement data retention policies

For additional assistance, visit our troubleshooting guide or report an issue.