Data Tag

Overview

Holds structured data — a JSON object or array, an XML document, position/coordinate data — rather than a single value. Use this for anything that doesn't reduce to one number, one piece of text, or one true/false, such as a robot's Cartesian position, a machine's full status block, or a file's parsed contents.

Value

A structured (JSON-shaped) object. Incoming XML is automatically converted to the equivalent JSON structure before storage/transform.

Transform options

DataTag's Transform works differently from the other types: instead of typing an expression directly into the field, you enter the filename of a JOLT transform spec stored on the server (under config/Transforms/). JOLT is a JSON-to-JSON transformation format — the spec file describes how to reshape, rename, filter, or restructure the incoming data.

Example: Transform set to robot-position.json looks for config/Transforms/robot-position.json and applies it to every incoming reading using the rules defined in that file.

Setting up a new JOLT spec file itself isn't done from the tag's Details page — it needs to already exist on the server. Talk to your system integrator/support contact if you need a new transform spec written.

Transforms can be tested using the following link: https://jolt-demo.appspot.com/#inception

Type Attributes

DataTag doesn't use Type Attributes — the field has no effect if set.

Notes

• If the named spec file doesn't exist on the server (or can't be parsed), the tag fails to apply that reading rather than falling back to the raw, untransformed data — double-check the spec file is actually deployed before pointing a tag's Transform at it.