AMIModel1700LLI Satellite#

Name	AMIModel1700LLI
Description	Satellite to read the AMI Model1700 LLI level sensor
Language	Python
Category	Environment Sensors
Website	madmax/hamburg/amimodel1700lli-satellite

Description#

Constellation satellite to read Helium and Nitrogen levels from an AMI Model 1700 LLI.

Note

This satellite requires write access to the serial port or USB-to-serial converter the device is attached to. It is recommended to not run this satellite with root privileges but to allow the regular user access to the required port instead. On Unix, if the port is e.g. /dev/ttyUSB0, the group can be found via stat /dev/ttyUSB0 (the Gid entry). If the group is e.g. dialout, the permissions can be given with sudo usermod -a -G dialout $USER. A restart is required for the changes to be effective.

Configuration#

A calibration curve is required for both Helium and Nitrogen levels to convert the measured fill level in mm to percentage of the actual volume. It is specified by an offset and a list of fill levels in mm and their corresponding percentages. A measurement val_mm is then converted to percentage by np.interp(val_mm + offset_mm, levels_mm, percentages).

Parameter	Description	Type	Default Value
`port`	Path to serial device, e.g. `/dev/ttyUSB0`	String
`n2_enabled`	Enable Nitrogen measurements	Boolean	`False`
`n2_interval`	Sampling interval of nitrogen level in seconds	Integer	`60`
`n2_offset_mm`	Offset of Nitrogen measurement, in `mm`	Integer
`n2_levels_mm`	Levels of Nitrogen calibration curve	List
`n2_percentages`	Percentages of Nitrogen calibration curve	List
`he_enabled`	Enable Nitrogen measurements	Boolean	`True`
`he_interval`	Sampling interval of helium level in seconds	Integer	`60`
`he_offset_mm`	Offset of Helium measurement, in `mm`	Integer
`he_levels_mm`	Levels of Helium calibration curve	List
`he_percentages`	Percentages of Helium calibration curve	List

Important

The satellite does NOT configure the devices measurement mode (sample and hold vs. continuous) and relies on the device being configured to periodically update its measurement. **_interval defines how often the satellite queries the device for a new measurement but DOES NOT initiate an actual sample on the device. It is therefore advisable to set it to the smallest sampling period you plan to operate the device with.

Example#

[satellites.AMIModel1700LLI.L0]
port = "/dev/ttyL0"
n2_enabled = 0
n2_offset_mm = 27.5
n2_levels_mm = [0, 37, 72.5, 145, 217.5, 290, 292]
n2_percentages = [0, 12.8, 25, 50, 75, 100, 100.7]
he_enabled = 1
he_offset_mm = 17.5
he_levels_mm = [0, 30.2, 50.2, 70.2, 95.7, 121.2, 146.7, 172.2, 197.7, 223.2, 248.7, 274.2, 290]
he_percentages = [0, 10.4, 17.3, 24.2, 33, 41.8, 50.6, 59.4, 68.2, 77, 85.8, 94.6, 100]

Metrics#

Metric	Description	Value Type	Metric Type	Interval
`LEVEL_N2`	The Nitrogen level in percent, as determined by the provided calibration curve.(requires `n2_enabled = True`)	Float	`LAST_VALUE`	configurable
`LEVEL_N2_CM`	The raw Nitrogen level as returned by the device in `cm` (requires `n2_enabled = True`)	Float	`LAST_VALUE`	configurable
`LEVEL_HE`	The Helium level in percent, as determined by the provided calibration curve (requires `he_enabled = True`)	Float	`LAST_VALUE`	configurable
`LEVEL_HE_CM`	The raw Helium level as returned by the device in `cm` (requires `he_enabled = True`)	Float	`LAST_VALUE`	configurable

Framework Parameters#

This satellite inherits the following framework parameters from its base classes:

Parameters inherited from `Satellite`#

Autonomous Operation#

Parameters to control autonomy in the _autonomy section:

Parameter	Type	Description	Default Value
`role`	Role name	Role this satellite should take in the Constellation. Accepted values are `ESSENTIAL`, `DYNAMIC`, `TRANSIENT` and `NONE`.	`DYNAMIC`
`max_heartbeat_interval`	Unsigned integer	Maximum interval in seconds between heartbeats to be sent to other Constellation components. The time between heartbeat is adjusted automatically according to the number of nodes in the Constellation but will never exceed this value.	`30`

Conditional Transitions#

Parameters to control conditional transitions in the _conditions section:

Parameter	Type	Description	Default Value
`require_initializing_after`	List of strings	List of canonical names of remote satellites for conditional transitioning in `initializing` state	-
`require_launching_after`	List of strings	List of canonical names of remote satellites for conditional transitioning in `launching` state	-
`require_landing_after`	List of strings	List of canonical names of remote satellites for conditional transitioning in `landing` state	-
`require_starting_after`	List of strings	List of canonical names of remote satellites for conditional transitioning in `starting` state	-
`require_stopping_after`	List of strings	List of canonical names of remote satellites for conditional transitioning in `stopping` state	-
`transition_timeout`	Unsigned integer	Timeout in seconds to wait for all conditions to be satisfied for conditional transitioning	`30`

Framework Metrics#

This satellite inherits the following framework metrics from its base classes:

Metrics inherited from `Satellite`#

None