SMART Box device

The SMART Box Tango devices reflect the state of the individual FNSC (Field Node SMART Box Controller) devices, including FEM port power status. The following attributes are exposed; note all attributes are read-only with the exception of the alarm and warning thresholds, and FEM current trip thresholds. All temperatures are in degrees Celsius.

Tango attribute name	Register address(es)	Register description
ModbusRegisterMapRevisionNumber	1	Modbus FNPC register map revision number, fixed at firmware compile time
PcbRevisionNumber	2	FNCB revision number, fixed at firmware compile time
CpuId	3-4	Microcontroller device ID
ChipId	5-12	Microcontroller unique device ID
FirmwareVersion	13	Firmware revision number, fixed at compile time
Uptime	14-15	Time, in seconds, since FNPC boot
SysAddress	16	Modbus address
InputVoltage	17	Incoming 48Vdc voltage
PowerSupplyOutputVoltage	18	PSU output voltage
PowerSupplyTemperature	19	PSU temperature
PcbTemperature	20	PCB temperature
FemAmbientTemperature	21	Thermistor mounted on sensor board in the FEM package
PasdStatus	22	SMART Box system status
LedPattern	23	Status of the service and status LEDs
FemCaseTemperature1	24	FEM 6 temperature (thermistor mounted on top of FEM case)
FemCaseTemperature2	25	FEM 12 temperature (thermistor mounted on top of FEM case)
FemHeatsinkTemperature1	26	Thermistor mounted on heatsink between FEMs 9 and 10
FemHeatsinkTemperature2	27	Thermistor mounted on heatsink between FEMs 3 and 4
PortForcings	36-47	Port forcing status for each port (“ON”, “OFF”, or “NONE”)
PortBreakersTripped	36-47	Firmware circuit breaker status for each port (True if trip has occurred)
PortsDesiredPowerOnline	36-47	Desired state of each port when FNSC is ONLINE (“OFF, “ON” or “DEFAULT”)
PortsDesiredPowerOffline	36-47	Desired state of each port when FNSC is OFFLINE (“OFF, “ON” or “DEFAULT”)
PortsPowerSensed	36-47	Power sensed status for each port (True or False)
PortsCurrentDraw	48-59	List of FEM current measurements (mA)
InputVoltageThresholds	1001-1004	High alarm, high warning, low warning and low alarm threshold values
PowerSupplyOutputVoltageThresholds	1005-1008	High alarm, high warning, low warning and low alarm threshold values
PowerSupplyTemperatureThresholds	1009-1012	High alarm, high warning, low warning and low alarm threshold values
PcbTemperatureThresholds	1013-1016	High alarm, high warning, low warning and low alarm threshold values
FemAmbientTemperatureThresholds	1017-1020	High alarm, high warning, low warning and low alarm threshold values
FemCaseTemperature1Thresholds	1021-1024	High alarm, high warning, low warning and low alarm threshold values
FemCaseTemperature2Thresholds	1025-1028	High alarm, high warning, low warning and low alarm threshold values
FemHeatsinkTemperature1Thresholds	1029-1032	High alarm, high warning, low warning and low alarm threshold values
FemHeatsinkTemperature2Thresholds	1033-1036	High alarm, high warning, low warning and low alarm threshold values
FemCurrentTripThresholds	1069-1080	12 FEM current trip thresholds (mA)
WarningFlags	10130	List of sensors in WARNING state
AlarmFlags	10132	List of sensors in ALARM state
ThresholdDifferences		Dict of the differences in thresholds between firmware and tango DB

The SMART Box PasdStatus attribute should be interpreted as follows:

PasdStatus attribute value	Meaning
OK	Initialised, system health OK
WARNING	Initialised, and at least one sensor in WARNING
ALARM	Initialised, and at least one sensor in ALARM
RECOVERY	Initialised, and at least one sensor in RECOVERY
UNINITIALISED	Not initialised, regardless of sensor states
POWERDOWN	Local tech initiated power-down sequence

SMART Box commands

The SMART Box devices support the following commands:

Command name	Arguments	Description
PowerOnPort	Port number	Request to power on the specified FEM port
PowerOffPort	Port number	Request to power off the specified FEM port
SetAntennaMasking	JSON antenna-mask dict	Set the masked status for one or more antennas (see below)
SetPortPowers	See: Setting port powers	Initialise the SMART Box and request the specified port power statuses
UpdateThresholdCache	None	Resync the threshold caches from firmware and tango database
ClearThresholdCache	None	Clear the tango DB threshold cache values

Antenna masking

SetAntennaMasking accepts a JSON string that maps antenna names to a boolean masked status, for example:

'{"sb01-01": true, "sb01-03": false}'

true means the antenna is masked — its port will not be powered on. false unmasks the antenna. Antennas absent from the dict are left unchanged, so partial updates are safe.

The command returns REJECTED if none of the supplied antenna names are known to this smartbox (e.g. all names are unrecognised, or the dict is empty). On success the port mask cache is updated immediately and the new MaskedAntennas list is persisted to the Tango database so that the masking state survives the device restarting.

Alarm recovery procedure

When the SMART Box PasdStatus attribute indicates an ALARM, WARNING or RECOVERY state, the WarningFlags and AlarmFlags attributes can be interrogated to find out which sensors have gone outside their threshold values. These registers need to be manually cleared by issuing the ResetSmartboxAlarms() and ResetSmartboxWarnings() commands after reading.

SMART Boxes automatically transition to the RECOVERY state when the relevant sensor values return to within their alarm thresholds. To return a SMART Box to an operational state after such an event, the InitializeSmartbox() command must be executed.

Setting Smartbox firmware thresholds

The attributes such as OutsideTemperatureThresholds are alarm threshold values stored in the firmware which are used internally for machine protection. To override the default values, these attributes are writeable when the device is put into ENGINEERING mode. To keep track of any overrides, when any of these values are changed they are cached in the Tango database. If a mismatch is detected between the firmware values and the Tango database (for example if the device is powered off, it will reset to the default firmware values on power up), the Smartbox device will be put into a FAULT state.

To check what values are different, read the ThresholdDifferences attribute to see the conflicts. You can then set the relevant attribute to the desired value, thus updating both the firmware and Tango database to the same value. When all conflicts have been resolved the FAULT state will be removed.

Two engineering commands are provided: UpdateThresholdCache which re-reads the database values and calculates the differences again, and ClearThresholdCache which deletes all cached values from the Tango database.

Smartbox health

The smartbox health is determined by three factors:

1. The value of monitoring points in relation to their defined thresholds.

2. The status as reported in the Smartbox’s SYS_STATUS register.

3. The status of the FEM port breakers.

Threshold Evaluation Each monitoring point has four thresholds: [min_alarm, min_warning, max_warning, max_alarm]. These set on the attributes and the attributes respond by moving through tango.AttrQuality.WARNING and tango.AttrQuality.ALARM respectively dependent on monitoring point value. The healthState then reflects this as HealthState.DEGRADED -> tango.AttrQuality.WARNING and HealthState.FAILED -> tango.AttrQuality.ALARM

We can change the thresholds at run time on the smartbox by using the Tango API:

For example:

attribute_config = smartbox.get_attribute_config("InputVoltage")
alarm_config = attribute_config.alarms
alarm_config.max_warning = "49.5"
alarm_config.max_alarm = "48.5"
alarm_config.min_warning = "45.5"
alarm_config.min_alarm = "41"
attribute_config.alarms = alarm_config
smartbox.set_attribute_config(attribute_config)

We can also change the thresholds at deploy time on the smartbox through the helm charts:

ska-tango-devices:
  deviceDefaults:
    MccsSmartbox:
      InputVoltage->max_alarm: 49.5
      InputVoltage->max_warning: 48.5
      InputVoltage->min_warning: 45.5
      InputVoltage->min_alarm: 41

  devices:
    MccsSmartbox:
      low-mccs/smartbox/s8-1-sb11:
        InputVoltage->max_alarm: 51.2

Status Register Evaluation

The following translation of the Smartbox’s SYS_STATUS register values to health states is applied:

• ‘ALARM’ or ‘RECOVERY’ indicates a health state of ‘FAILED’.

• ‘WARNING’ indicates a health state of ‘DEGRADED’.

• ‘UNINITIALISED’ or ‘OK’ indicates a health state of ‘OK’.

• ‘POWERDOWN’ indicates a health state of ‘UNKNOWN’ (this state should not be used).

Port Breaker Status

The number of port breakers tripped is reflected through the numberOfPortBreakersTripped attribute, this attribute can have thresholds configured as the other attributes above, by default it only has max alarm configured as such we go to HealthState.FAILED at a single port breaker tripped.