Part 211: Global Positioning (GPOS)
| Document number | OPC 10000-211 |
|---|---|
| IEC designation | IEC 62541-211 - publication not confirmed |
| Colloquially | Part 211 |
| Group | Domain |
Part 211 adds absolute geographic position to OPC UA: where a machine is on the earth, and which zone it is in. It builds directly on the relative spatial location model in Part 210, so both nodesets are required. Namespace http://opcfoundation.org/UA/GPOS/, released at version 1.0.0 on 2025-09-25.
What it defines
Geographic position as a modelled value rather than as a vendor-specific pair of floats: coordinates expressed against a named reference system, with the metadata that makes them interpretable. Alongside position, the model defines zones, which is what turns a coordinate stream into something operationally useful - a machine is not just at a coordinate, it is inside or outside a defined area, and the transition between them is an event somebody cares about. The zone concept is a named conformance unit of the model.
Why it depends on Part 210
The dependency is deliberate and it is a hard one: the global positioning model builds on the relative spatial location types. A machine's absolute position is the position of a specific point on it, and that point is defined by the relative model's attach points - the GPS antenna is not at the same place as the bucket, the mast or the load centre, and on a large machine the difference is metres. Loading the global positioning nodeset without the relative one will simply fail, and reasoning about absolute position without the relative chain gives you the position of the wrong part of the machine.
Where it is useful
Mobile and outdoor equipment: mining machinery, quarry and construction plant, port and yard equipment, automated guided vehicles, agricultural machines. For these, position is process data in the same sense a temperature is on a fixed asset, and zones carry the operational logic - a haul truck entering a loading zone, a crane leaving its permitted area. Having this in a standard model rather than in a proprietary telemetry channel is what lets it join the rest of the machine data on one connection.
Status and the conventions to pin
The released nodeset is at version 1.0.0 with a publication date of 2025-09-25, making it one of the newest published models and squarely early adopter. Note the version format: three parts rather than the four-part form used elsewhere in the standard, which is a small inconsistency worth knowing when you write a version comparison. As with any positioning system, the reference frame is not optional detail - a latitude and longitude without a stated geodetic datum is not a position, and the difference between datums is metres in some regions.
What it defines
| Concept | What it is |
|---|---|
| Namespace URI | http://opcfoundation.org/UA/GPOS/ - what to look for in NamespaceArray to establish whether a machine publishes absolute position at all. |
| Model version | Released at version 1.0.0, published 2025-09-25. Note the three-part version format, which differs from the four-part form used by most released models. |
| Dependency on relative spatial location | A hard dependency on the Part 210 model. Both nodesets must be loaded, and the absolute position is anchored to a point defined by the relative model. |
| Geographic position | Coordinates expressed against a named reference system with the metadata needed to interpret them, rather than a vendor-specific pair of numbers. |
| Zones | Named areas a machine can be inside or outside. This is where the operational meaning lives, and the zone concept is a named conformance unit of the model. |
| Reference frame and datum | The geodetic reference against which coordinates are stated. Without it a coordinate is not a location, and different datums differ by metres in some regions. |
| Antenna versus point of interest | The receiver's position is not the machine's working point. The relative model's attach points are what resolve the offset, which is why the dependency exists. |
| Target applications | Mining, construction, quarrying, ports and yards, automated guided vehicles and agricultural machinery - anywhere position is process data. |
Do you need to read it?
Integrators working with mobile or outdoor equipment, and anyone consolidating machine telemetry that currently arrives on a separate positioning channel. Also worth knowing for fleet analytics, because zone entry and exit is usually a better basis for utilisation figures than a raw coordinate stream.
Traps that trace back to this part
- The nodeset will not load without the relative spatial location nodeset. This surfaces as a model-load failure in a modelling tool or a server that refuses to start, and the error rarely names the missing dependency clearly. Load both, and pin both versions together.
- Absolute position without the relative chain is the position of the receiver, not of the machine's working point. On a large machine that is a difference of metres, which matters for zone logic and for anything safety-adjacent. Resolve through the attach points rather than treating the coordinate as the machine's location.
- A coordinate without its geodetic datum is not a position. Read the reference system the model states and carry it through your pipeline, because two systems quietly assuming different datums produce a persistent offset that looks like a calibration problem.
- This is a very new model at version 1.0.0, with a version format that differs from most released models. Confirm the specific device publishes the namespace, and write version comparisons that handle both three-part and four-part forms.
Last verified 7 September 2026 against OPC UA 1.05.07. The specification parts themselves are published by the OPC Foundation. OPC UA Connect is an educational resource and is not affiliated with the OPC Foundation.