Telescope integration

EDD keeps observatory-specific protocols at the edge of the system. A site may integrate directly with the Master Controller’s KATCP interface or deploy thin translation services for control commands and telescope metadata.

Telescope control interface

A control interface maps the local Telescope Control System (TCS) lifecycle to EDD provision, configure, capture, measurement, and teardown commands. It must:

  • serialize commands so a new transition is not sent while one is active;

  • map failures back to the TCS without hiding the affected EDD state;

  • preserve observation and scan identifiers;

  • handle reconnects without repeating non-idempotent scan actions; and

  • expose its own health and connection status.

At Effelsberg, an interface translates SCPI commands into KATCP. A site whose TCS already speaks KATCP can connect directly and omit this translation layer.

Telescope Metadata Interface

The TMI adapts local metadata sources and makes normalized values available to pipelines. Common fields include source name and coordinates, receiver, project, observation and scan number, frequency setup, noise-diode state, weather, and telescope status.

Define for every field:

  • name, type, unit, coordinate frame, and allowed null state;

  • source system and freshness limit;

  • update and interpolation rules;

  • behaviour when the source disconnects; and

  • which pipeline transition consumes it.

Metadata needed for a data header must be captured at the appropriate transition, not fetched later during offline reduction without provenance.

Status and compatibility services

Sites may deploy status servers for an existing observatory interface, FITS forwarders for legacy archives, or blocking clients that adapt synchronous systems to EDD’s asynchronous KATCP interface. These are services, not normal processing pipelines, unless they genuinely participate in the common state model.

Testing

Test telescope integration with a simulator before commissioning. Cover normal observations, rapid scan changes, TCS and TMI disconnects, duplicate commands, stale metadata, missing sources, EDD error and panic states, and recovery after restarting either side. Verify the metadata in final files, not only the values shown by the live service.