Devices
=====================================

This package implements the *Station Control (SC)* part of a LOFAR2.0 station, the core of which implements several Tango devices that connect to the station's hardware as well as to each other. In the following graph, green components are implemented in this package, the gray components are external:

.. graphviz::

    digraph logical_layout {
      fontname="Helvetica,Arial,sans-serif"
      node [fontname="Helvetica,Arial,sans-serif" fontsize="20pt" style=filled]
      edge [fontname="Helvetica,Arial,sans-serif" fontsize="20pt"]

      subgraph clusterSC {
        label = "SC";

        node [shape=ellipse color=aquamarine];

        ObservationControl -> Observation;
        Observation -> SDP;
        Observation -> AntennaField;
        Observation -> TileBeam;
        Observation -> DigitalBeam;

        AntennaField -> RECV;
        TileBeam -> AntennaField;
        DigitalBeam -> Beamlet;
        DigitalBeam -> AntennaField;

        SST -> SDP;
        XST -> SDP;
        BST -> SDP;

        APSCT;
        APSPU;
        UNB2;

        PSOC;
      }

      subgraph clusterSDP {
        label = "SDP";

        SDPTR -> Firmware;
        UNB2TR -> Uniboard2;
      }
      SDP -> SDPTR;
      Beamlet -> SDPTR;
      SST -> SDPTR;
      XST -> SDPTR;
      BST -> SDPTR;
      UNB2 -> UNB2TR;

      subgraph clusterRECV {
        label = "RECV";

        RECVTR -> RCU -> HBAT;
      }
      RECV -> RECVTR;

      subgraph clusterAPSCT {
        label = "APSCT";

        APSCTTR;
      }
      APSCT -> APSCTTR;

      subgraph clusterAPSPU {
        label = "APSPU";

        APSPUTR;
      }
      APSPU -> APSPUTR;

      subgraph clusterPSOC {
        label = "PSOC";
      }
      PSOC -> clusterPSOC;
    }

A brief description of each of these devices:

* `ObservationControl` device spawns new Observation devices, given an observation specification,
* `Observation` device sets up the software and hardware on the station to execute a given specification,
* `AntennaField` device controls a set of antennas and their properties (f.e. their positions),
* `RECV` device represents the hardware that controls the antennas in the station,
* `TileBeam` device steers the beam of the HBA tiles, actively tracking any source,
* `SDP` device represents generic functionality of the firmware that digitally combines antenna inputs,
* `SST`, `XST`, and `BST` devices control and expose statistics generated by the SDP firmware,
* `Beamlet` device controls the observation output data (beamlets) that stream out of the station (in LOFAR, to CEP),
* `DigitalBeam` device steers the beam formed in SDP, actively tracking any source.

Auxilliary devices that control hardware are:

* `APSCT` device controls the ASPCT clock selection and distribution board,
* `APSPU` device controls the APSPU 48V distribution board,
* `UNB2` device controls the Uniboards that hold the SDP FPGAs (and thus firmware).
* `PSOC` device controls the power sockets (230V distribution).

Finally, the stack holds the auxilliary devices that control the software devices. They connect to too many devices to draw:

* `Docker` device controls the Docker containers of the software stack,
* `TemperatureManager` device acts on temperature alarms originating from the hardware.