LOW.CSP LMC Documentation

The top-level software components provided by Low.CSP LMC API are:

Components listed above are implemented as TANGO devices, i.e. classes that implement standard TANGO API. The CSP.LMC TANGO devices are based on the standard SKA1 TANGO Element Devices provided via the SKA Base Classes.

Low.CSP LMC Controller

Low.CSP Controller is the top‐level TANGO Device and the primary point of contact for monitor and control of the Low.CSP Sub-syste.

The Low.CSP Controller represents Low.CSP Sub-system as a unit for control and monitoring for general operations.

Low.CSP Controller main roles are:

  • To be the central control node for Low.CSP. The Controller provides a single point of access for control of the Low.CSP as a whole, this includes provision for housekeeping and supervisory commands including: power‐up, power‐down, power management, restart (re‐initialize), support for firmware and software upgrades, etc.

  • To provide rolled‐up reporting for the overall Low.CSP status. Low.CSP Controller monitors and intelligently rolls‐up status reported by Low.CSP equipment, sub‐arrays and capabilities and maintains a standard set of states and modes, as defined in the document “SKA1 Control System Guidelines”. State transitions are reported using standard TANGO mechanism.

  • To implement a set of attributes that represent the status and configuration of the Low.CSP as a whole and, where required, report availability, status and configuration of the Low.CSP equipment, components and capabilities (in the form of lists or tables or JSON string).

  • To maintains the pool of resources (VCCs, FSPs, Search/Timing/VLBI beams), keep track of allocation to sub‐arrays and provide reports on resource availability, allocation, and more.

Low.CSP Controller implementation is based on (derived from) the standard SKA1 TANGO Device Controller; Low.CSP Controller implements the standard TANGO API, aligned with the document “SKA1 Control System Guidelines”.

The interface is between a TANGO client and a TANGO Device. The TANGO Device exposes attributes and commands to clients.

The roles of the interfacing systems are:

  • TANGO Clients: Low.TMC sub-system TANGO client(s).

  • TANGO Device: Low.CSP sub-system implements Low.CSP Controller.

The clients use requests to obtain read and/or write access to TANGO device attributes, and to invoke TANGO device commands.

Low.CSP Controller TANGO Device name

The Controller TANGO Device name is defined in the document “SKA1 TANGO Naming Conventions”:

low-csp/control/0

Low.CSP Controller TANGO Device Properties

The Low.CSP Controller device has a standard set of properties inherited from the SKA Controller TANGO Device and a number of specific properties documented in the Controller API section.

Low.CSP Controller TANGO Device States and Modes

Low.CSP Controller implements the standard set of state and mode attributes defined by the SKA Control Model.

Low.CSP Controller reports on behalf of the Low.CSP Sub-system – unless explicitly stated otherwise, the state and mode attributes implemented by the Low.CSP Controller represent the status of the Low.CSP as a whole, not the status of the Low.CSP Controller itself.

Low.CSP Controller operational state

The Low.CSP Controller supports the following sub-set of the TANGO Device states:

  • UNKNOWN: Low.CSP is unresponsive, e.g. due to communication loss. This state cannot be reported by CSP itself.

  • OFF: power is disconnected. This state cannot be reported by CSP itself

  • INIT: Initialization of the monitor and control network,equipment and functionality is being performed. During initialization commands that request state transition to OFF (power-down) or re‐start initialization are accepted.

  • DISABLE: Low.CSP is administratively disabled, either by setting adminMode=OFFLINE or NOT-FITTED. Basic monitor and control functionality is available but signal processing functionality and related commands are not available. All sub‐arrays are empty (OFF) and IDLE; all resources (receptors, tide‐array beams) are placed in the pool of unused resources.)

  • STANDBY: Low‐power state, Low.CSP uses < 5% of nominal power. Basic monitor and control functionality is available, including the commands to request state transition to ON, OFF, DISABLE, or INIT. Signal processing functionality and related commands are not available. All sub‐arrays are empty (OFF) and IDLE; all resources (receptors, tide‐array beams) are placed in the pool of unused resources.).

  • ON: At least a minimum of CSP signal processing capability is available; at least one receptor and one sub‐array can be used for observing (either for scientific observations or for testing andmaintenance). Low.CSP is in normal operational state, all commands, including commands to increase/decrease functional availability and power consumption are available.

  • ALARM: Quality Factor for at least one attribute crossed the ALARM threshold. Part of Low.CSP functionality may be unavailable.

  • FAULT: Unrecoverable fault has been detected, Low.CSP is not available for use at all, maintainer/operator intervention is required in order to return to ON, STANDBY, or DISABLE. Depending on the extent of failure commands restart and init, as well as status reporting may be available.

Low.CSP Controller TANGO Device Commands

Low.CSP Controller implements the standard set of commands as specified in:

  • Standard set of TANGO Device commands as defined in TANGO User Manual

  • Standard set of SKA TANGO Device commands

  • Command specific to Low.CSP Controller as described in API section.

Low.CSP makes provision for TM to request state transitions for individual sub‐systems and/or Capabilities.

Low.CSP Controller TANGO Device Attributes

Low.CSP Controller implements the standard set of attributes as specified in:

  • Standard set of TANGO Device attributes as defined in TANGO User Manual

  • The standard set of SKA TANGO Device attributes as defined for the SKA Controller TANGO Device.

  • Attributes to Low.CSP Controller as described in API section.

The Low.CSP Controller maintains the ‘pool of resources’ and is able to provide information regarding sub‐array membership, status and usage.

Low.CSP LMC Subarray

The core CSP functionality, configuration and execution of signal processing, is configured, controlled and monitored via subarrays.

CSP Subarray makes provision to TM to configure a subarray, select Processing Mode and related parameters, specify when to start/stop signal processing and/or generation of output products. TM accesses directly a CSP Subarray to:

  • Assign resources

  • Configure a scan

  • Control and monitor states/operations

Resources assignment

The assignment of Capabilities to a subarray (subarray composition) is performed in advance of a scan configuration. Assignable Capabilities for LOW CSP.LMC Subarrays are:

  • stations

  • station beams

  • tied-array beams: Search Beams, Timing Beams and Vlbi Beams.

In general resource assignment to a subarray is exclusive, but in some cases the same Capability instance may be used in shared manner by more then one subarray.

Inherent Capabilities

Each CSP subarray has also five permanently assigned inherent Capabilities:

  • Station Beam

  • Correlation

  • PSS

  • PST

  • VLBI

An inherent Capability can be enabled or disabled, but cannot assigned or removed to/from a subarray. They correspond to the CSP Low Processing Modes and are configured via a scan configuration.

Scan configuration

TM provides a complete scan configuration to a subarray via an ASCII JSON encoded string. Parameters specified via a JSON string are implemented as TANGO Device attributes and can be accessed and modified directly using the buil-in TANGO method write_attribute. When a complete and coherent scan configuration is received and the subarray configuration (or re-configuration) completed, the subarray it’s ready to observe.

Control and Monitoring

Each Low CSP.LMC Subarray maintains and reports the status and state transitions for the Low CSP subarray as a whole and for the individual assigned resources.

In addition to pre-configured status reporting, a Low CSP Subarray makes provision for the TM and any authorized client, to obtain the value of any subarray attribute.

Low.CSP Subarray TANGO Device name

The Low.CSP Subarray TANGO Device name is defined in the document “SKA1 TANGO Naming Conventions”:

low-csp/subarray/XY

where XY is a two digit number in range [01,..,16].

Low.CSP Subarray operational state

Low.CSP Subarray intelligently rolls‐up the operational state of all components used by the sub‐array and reports the overall operational state for the sub‐array.

The Low.CSP Subarray supports the following sub-set of the TANGO Device states:

  • UNKNOWN: Low.CSP sub-array is unresponsive, e.g. due to communication loss.

  • OFF: The sub-array is not enabled to perform signal processing. The sub‐array is ‘empty’.

  • INIT: Initialization of the monitor and control network,equipment and functionality is being performed.

  • DISABLE: Low.CSP sub-array is administratively disabled, basic monitor and control functionality is available but signal processing functionality is not available.

  • ON: The sub-array is enabled to perform signal processing. The sub‐array observing state is EMPTY if receptors have not been assigned to the sub‐array, yet.

  • ALARM: Quality Factor for at least one attribute crossed the ALARM threshold. Part of functionality may be unavailable.

  • FAULT: Unrecoverable fault has been detected. The sub‐array is not available for use and maintainer/operator intervention might be required.

Low.CSP Subarray observing state

The sub‐array Observing State indicates status related to scan configuration and execution.

The Low.CSP Subarray observing state adheres to the State Machine defined by ADR-8.

Low.CSP Subarray TANGO Device Commands

Low.CSP Subarray implements the standard set of commands as specified in:

  • Standard set of TANGO Device commands as defined in TANGO User Manual

  • Standard set of SKA TANGO Device commands

  • Command specific to Low.CSP Subarray as described in API section.

Low.CSP makes provision for TM to request state transitions for individual sub‐systems and/or Capabilities.

Low.CSP Subarray TANGO Device Attributes

Low.CSP Subarray implements the standard set of attributes as specified in:

  • Standard set of TANGO Device attributes as defined in TANGO User Manual

  • The standard set of SKA TANGO Device attributes as defined for the SKA Subarray TANGO Device.

  • Attributes to Low.CSP Subarray as described in API section.

Virtually all parameters provided in scan configuration are exposed as attributes either by Low.CSP Subarray or by individual Capabilities.