HealthState Aggregation in Telescope Low

Overview

This document explains how HealthState aggregation works in the Telescope Low system. The overall system state is determined by aggregating the health states of multiple subsystems, with AdminMode as an input factor.

HealthState Aggregation

Each subsystem reports a HealthState, which can be one of:

  • OK – Fully functional.

  • DEGRADED – Partially functional with issues.

  • FAILED – Non-functional.

  • UNKNOWN – Health state is unavailable.

### Aggregation Rules:

  1. If any subsystem is in FAILED, the system health is FAILED.

  2. If no subsystems are FAILED, but any subsystem is DEGRADED, the system health is DEGRADED.

  3. If all subsystems are OK, the system health is OK.

  4. If all subsystems are UNKNOWN, the system health is UNKNOWN.

#### Example:

Subsystem

HealthState

System Health

CSP Subarray SDP Subarray MCCS Subarray

OK DEGRADED OK

OK DEGRADED DEGRADED

Effect of AdminMode on HealthState

Although AdminMode is not aggregated separately, it influences HealthState aggregation.

### AdminMode States:

  • ONLINE – Fully operational and configurable.

  • OFFLINE – Not available for operations.

  • MAINTENANCE – Undergoing maintenance.

  • NOT_FITTED – Not installed or part of the system.

  • STANDBY – Inactive or low-power state.

### Impact of AdminMode on HealthState:

  1. If AdminMode is OFFLINE, the subsystem’s HealthState is ignored.

  2. If AdminMode is NOT_FITTED, the subsystem is excluded from aggregation.

  3. If AdminMode is MAINTENANCE, HealthState is informative but does not affect system-wide aggregation.

  4. Otherwise, HealthState aggregation follows the rules mentioned earlier.

#### Example:

Subsystem

AdminMode

HealthState

System Health

System Mode

CSP Subarray SDP Subarray MCCS Subarray

ONLINE ONLINE OFFLINE

OK DEGRADED FAILED

DEGRADED DEGRADED DEGRADED

ONLINE ONLINE OFFLINE

🔹 Note: Since MCCS Subarray is OFFLINE, its FAILED state is ignored. The system health is DEGRADED instead of FAILED.

Warning

Although TMC devices provide the SetAdminMode command to set the AdminMode of lower-level devices and subsystems, its usage is discouraged. The functionality is not consistently implemented across all subsystems, and using this command may lead to system inconsistencies. Full implementation of AdminMode is expected by the end of PI 27.

Usage in TMC LOW

  • This aggregation logic is applied in CSP, MCCS, and SDP for system monitoring.

  • Ensures accurate system-wide health representation.

  • AdminMode is used as an input to HealthState aggregation, preventing unnecessary alerts for offline or maintenance subsystems.