DataTalk logo docs

Tag Database

Table Of Contents

Tag Database Overview

The Tag Database in DataTalk is a central tool for managing and structuring tags within a project. It serves as a hub for creating, editing, and organizing tags, as well as defining their data types, limits, and other key properties. Additionally, the Tag Database enables real-time interaction with PLCs, providing live data monitoring and logging functionalities.

Key Features:

1. Tag Creation and Management:

  • Add, modify, or delete tags.
  • Define tag properties such as data type, scale, limits, and more.
  • Centralized changes: When limits or properties are modified in the Tag Database, those changes apply universally across the project wherever the tag is used.

2. Real-Time Data Display:

  • Tags can display live values read directly from PLCs.
  • The “Read Values” feature allows you to view current data from “expanded” connection tabs.

3. Limits for Alarms and Alerts:

  • Define limits for each tag to set thresholds for system checks.
  • If a tag’s value exceeds the specified limits, it can trigger alarms or animations.

4. Log Groups for Data Logging:

  • Assign tags to log groups to log their values over time.
  • Logged data can be visualized in charts or tables.
  • Data is logged only when the tag value changes, with the period determining how often the value is checked for updates.

5. Integration with Animations and Alarms:

  • Tags can act as triggers for animations and alarms, creating a dynamic and interactive project environment.
FeatureFeature desc.
ValueDisplays the live value read from the PLC when “Read Values” is clicked.
AddressSpecifies the data point’s address in the PLC.
Type
The data type of the tag (e.g., integer, float, boolean).
Access
Controls user access to specific tags.
LabelServes as internal notes; additional language-specific fields appear if multiple languages are configured.
ScaleEnables automatic scaling of values during read/write operations (e.g., multiplication or division).
LimitsDefines thresholds for alarms/alerts.
LogIndicates whether the tag’s values should be logged.
Log GroupsAssigns the tag to a log group for data logging.
UnitSpecifies the unit of measurement for the value (e.g., °C, kPa, etc.).
FormatAllows formatting of tag values (e.g., setting default decimal points).
GatewayEnables gateway configuration for advanced networking setups.

What’s tag?

A tag in a SCADA system represents a programmatic variable tied to a physical or virtual data source, often a PLC. Each tag includes:
Value: The current data read from the source.
Timestamp: The time when the value was recorded.
Quality: Indicates the reliability or accuracy of the data.
Tags are fundamental for representing real-world data, such as sensor readings, equipment statuses, or control signals, within the DataTalk system

Updated on December 5, 2024