Power Management in MCCS Subsystem
Hardware Power Modes
SKA hardware may support up to three power modes:
ON: The hardware is powered on and fully operational. This mode is supported by all SKA hardware.
OFF: The hardware is powered off.
STANDBY: The hardware is in a low-power standby mode. This mode is important in two scenarios:
When powering up a subsystem with many devices, limiting the inrush current is crucial. This is achieved by powering devices into standby mode, using no more than 5% of their nominal power, and then carefully orchestrating transitions to full power.
When powering up a device from off could take a long time (e.g., several minutes), the device may instead be powered up into standby mode. In standby mode, power consumption is low, but the time to fully power on the hardware is short (a couple of seconds).
Standby mode is not supported by all hardware; there may be very few devices that support it.
Power Mode Breakdown
Generally, a hardware device cannot turn itself off because once it is off, it loses the ability to turn itself back on. Instead, power to a device is controlled by an upstream device. For example, power to a TPM is controlled by the subrack in which that TPM is installed. Standby mode is generally managed by an ensemble of devices (e.g., SpsStation, FieldStation) by selectively turning off the most power-consuming devices. Thus, the implementation of the three power modes breaks down into:
On(): Tell the upstream device to supply power to the device, then tell the device itself to go fully operational.
Off(): Tell the upstream device (e.g., subrack) to deny power to the device (e.g., TPM).
Standby(): Selectively turn ON some sub-devices and turn OFF or leave OFF the TPMs (in the SPS Station) and the antennas and Front End modules (in the Field Station).
Power Commands
Power commands