Ignition Module Metadata Support

Overview

The module can send tag metadata from Ignition to Timebase alongside the tag's time-series data. Metadata includes engineering units, descriptions, format strings, and custom tag properties. Once stored in Timebase, this information is displayed alongside the data — for example, a chart axis can show the unit of measure, or a tooltip can show the description.

Metadata is stored per tag and only the current (latest) values are kept. Timebase does not track historical changes to metadata — if you change a tag's engineering unit, the new unit applies going forward.

Enabling Metadata for a Tag

Metadata collection is controlled by the Include Metadata setting on each tag individually:

1. In Ignition Designer, open the Tag Browser.
2. Right-click the tag and select Edit Tag.
3. On the History tab, enable Include Metadata.
4. Save the tag.

No additional configuration is required on the historian provider itself.

What Gets Sent to Timebase

When Include Metadata is enabled, the module maps the following Ignition tag properties to Timebase fields:

Data Type Mapping

The tag's data type is always included in metadata, regardless of the Include Metadata setting:

Format String Compatibility

Ignition uses Java's DecimalFormat syntax for format strings; Timebase uses .NET's custom numeric format syntax. Most common patterns are identical between the two (0.00, #,##0.00, 0.0%) and are passed through directly.

However, the following Java-only patterns are not sent to Timebase, as they would render incorrectly:

• Single-quote literals ('text') — used in Java for literal text in format strings
• The currency placeholder (¤)
• More than two semicolon-separated sections (Java supports two; .NET supports three with different meanings)

If your format string uses any of these patterns, the f field is omitted from the Timebase metadata update. The existing value in Timebase is preserved — it is not cleared. A trace-level log entry is written with the tag path and format string for debugging.

Custom Properties

User-defined custom tag properties (those not part of Ignition's standard tag property set) are captured and sent to Timebase in the fl (custom fields) object. Each custom property appears as a key-value pair.

Known limitation: Custom property changes that occur without a simultaneous change to a standard property (Tooltip, Eng Unit, Format String, Data Type) may not be sent immediately. Custom property updates are captured the next time a standard property change triggers a metadata event. If custom properties change frequently without standard property changes, the fl values in Timebase may lag behind Ignition.

When Metadata Is Sent

Metadata is sent in two situations:

1. Tag initialization — When a tag with Include Metadata enabled is first set up (or the module starts with the tag already configured), the current metadata values are sent to Timebase.
2. Property change — When any of the monitored metadata properties (Tooltip, Eng Unit, Format String, or Data Type) changes on a running tag.

Metadata is only sent when values have actually changed. The module compares the new metadata against a local cache of what Timebase currently holds for each tag, and only sends an update if something is different. This avoids unnecessary API calls.

What Happens When Include Metadata Is Disabled

If you disable Include Metadata on a tag, the module stops sending Tooltip, Eng Unit, Format String, and custom properties to Timebase. The tag's data type continues to be sent (it is always required).

Disabling Include Metadata does not clear the existing metadata from Timebase. The last values that were sent remain on the tag record until something updates them.

Troubleshooting