Properties

Configuration, status and telemetry download from the device is handled using a number of property variables. Each variable has a type (signed/unsigned integers, floating point numbers, strings, etc.) and a default value. Some properties are used for configuration and can be modified and stored in (optionally write-protected) non-volatile memory. Others are read-only and used for telemetry purposes. Some property changes take effect immediately, while others require a store and a system reset after update.

The system properties are divided into a number of property groups, each covering a specific part of the firmware.

Property values can be listed, modified and stored using the prop debug shell commands or remotely through the Property Client Library. As an example, to change the CSP address of the device to 21 and the default interface to RS422/KISS, run:

[polaris] prop get sys.csp.address
20
[polaris] prop set sys.csp.address 21
[polaris] prop set sys.csp.routes "0/0 KISS"
[polaris] prop unlock sys
[polaris] prop save sys
[polaris] prop unlock -f sys
[polaris] prop save -f sys
[polaris] reboot
...
[polaris] prop get sys.csp.address
21
[polaris] prop get sys.csp.routes
"0/0 KISS"

System Group

The sys group contains system parameters that should remain fixed after launch. The group can be stored twice in boot and fallback configuration. Both are write-protected and must be unlocked using prop unlock before they can be written to.

Property

Type

Default

Description

sys.name

string

polaris

String name for system

sys.serial

uint32

Serial number/ID

sys.sw.version

uint32

Running software version

sys.bootcount

uint32

Number of times the system was booted

sys.csp.address

uint8

20

CSP address of the device

sys.csp.routes

string

Additional CSP routes in CIDR notation

sys.can.rate

uint32

1000000

CAN-bus bitrate

sys.uart.rate

uint32

1000000

UART baudrate

sys.uart.multidrop

bool

False

UART multidrop mode

sys.net.enable

bool

False

IP stack enable

sys.net.ip

string

192.168.100.20

Ethernet IP address

sys.net.prefix

uint8

24

Ethernet network prefix bits

sys.net.gw

string

192.168.100.1

Ethernet gateway IP address

Configuration Group

The conf group contains runtime settings. The group can be stored to the boot configuration and is not write protected.

Property

Type

Default

Description

conf.led.enable

bool

False

Onboard LEDs enabled

conf.fs.mount

bool

False

Mount SD-card file system

The power channels are powered off at boot time, but powered on when the demodulator starts.

Telemetry Group

Telemetry values are stored in the tm group and updated once every second. The group does not support storage.

Property

Type

Default

Description

tm.temp.mcu

int16

MCU package temperature

tm.temp.fpga

int16

FPGA junction temperature

tm.temp.power

int16

Power conversion temperature

tm.temp.lna

int16

LNA temperature

tm.temp.adc

int16

ADC temperature

tm.temp.sdcard

int16

SD-card temperature

tm.volt.vin

uint16

Input voltage

tm.volt.3v3

uint16

3.3 V rail voltage

tm.volt.2v0

uint16

2.0 V rail voltage

tm.volt.1v0

uint16

1.0 V rail voltage

tm.cur.vin

int16

Input current

tm.cur.3v3

int16

3.3 V rail current

tm.cur.2v0

int16

2.0 V rail current

tm.cur.1v0

int16

1.0 V rail current

tm.power.vin

uint16

Input power

tm.power.3v3

uint16

3.3 V rail power

tm.power.2v0

uint16

2.0 V rail power

tm.power.1v0

uint16

1.0 V rail power

Demodulator Group

The demod group contains configuration and information on the demodulator. The group can be stored to the boot configuration and is not write protected.

Property

Type

Default

Description

demod.enable

bool

True

Enable or disable demodulator

demod.decoded

uint32

0

Number of decoded messages with correct FCS

demod.detected

uint32

0

Number of detected messages

demod.rate

uint16

Number of frames received in the last minute

demod.rf.gain

float

0.0

Front end RF gain offset from nominal

demod.pd.thres

double

3.0

Packet detection threshold

demod.pd.winlen

uint16

40

Packet detection window lenght

demod.pd.minlen

uint16

1500

Packet detection minimum length

demod.flip

uint8

1

Number of weakest bits to try and flip

demod.scale.min

uint16

Minimum scale parameter received

demod.scale.max

uint16

Maximum scale parameter received

demod.mean.min

int16

Minimum frequency offset received

demod.mean.max

int16

Maximum frequency offset received

demod.pps.valid

bool

PPS clocks valid

demod.pps.last

uint32

Last PPS clocks count

demod.pps.avg

uint32

Average PPS clocks count

Store Group

The AIS message store is controlled and monitored through the store group. The group can be stored to the boot configuration and is not write protected.

Property

Type

Default

Description

store.enable

bool

True

Enable or disable store

store.seq

uint32

Last sequence number stored

store.stored

uint32

Number of frames currently stored