- TaskStateProtocol An introduction to the Task-State-Protocol pattern
- Using XTT Short tutorial
- Middleware Abstraction Layer Using XTT over different communication frameworks
Sequencing engines with support for XTT¶
There are several sequencing engines supporting XTT, both generic and task-specific.
The most developed, and most widely used sequencing engine is actually far more than that: The dialog manager PaMini uses XTT as its interface for the robot system.
A fairly recent development is the StateChartExecutive (SCE), a generic sequencing engine based on Statechart-XML (SCXML). It does not include domain-specific support and is generally more "low-level", but also more generally applicable. SCE uses the data-mapper API for input and output (see below).
XTT itself provides generic state-management, but for a successful task, one also needs to communicate the goal. For this purpose, there is also a generic API that works across different middlewares, and can create data messages in their specific formats.