Broken Hardware

Not all hardware is always functional. Broken hardware must be excluded from the signal chain, and in some cases prevented from powering up.

Disabling antennas

Not all antennas present in the field are to be used. The AntennaField device exposes the following properties for each of its antennas:

Antenna_Quality:

The condition of the antenna: 0=OK, 1=SUSPICIOUS, 2=BROKEN, 3=BEYOND_REPAIR.

type:

int32[]

Antenna_Use:

Whether each antenna should be used: 0=AUTO, 1=ON, 2=OFF. In AUTO mode, an antenna is used if its quality is OK or SUSPICIOUS. In ON mode, it is always used. In OFF mode, never.

type:

int32[]

which can also be queried as Antenna_Quality_R and Antenna_Use_R.

Note

If these properties are updated, you should restart both the AntennaField and DigitalBeam device to propagate their effects.

The above settings result in a subset of the antennas in the AntennaField to be marked as usable. The following property exposes this conclusion:

Antenna_Usage_Mask_R:

Whether antennas will be used, according to their configured state and quality. Antennas which are configured to be BROKEN, BEYOND_REPAIR, or OFF, are not used.

type:

bool[N_tiles]

Effect on signal chain

The DigitalBeam device will only beamform inputs that are enabled in the AntennaField.Antenna_Usage_Mask_R attribute.

Power distribution

At boot, during hardware initialisation, the following devices toggle power:

• The RECV device turns all RCUs enabled in RCU_mask_RW OFF and ON,

• The RECV device powers its antennas according to its RCU_PWR_ANT_on_RW_default property,

• The AntennaField device powers its antennas, if they are: * Enabled in Antenna_Usage_Mask_R attribute, that is, not marked as BROKEN, BEYOND_REPAIR, or OFF, * Enabled in the Antenna_Needs_Power property.

Note

Exotic inputs like a noise source must not receive power, even when used. Use the Antenna_Needs_Power property to configure which antennas should be powered on.