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Automatic Meter Readings#

Pushing architecture#

In a pushing architecture the meter pushes data to Utilitarian at fixed intervals. This is a good general approach that simplifies AMR operations.

Polling architecture#

In a polling architecture Utilitarian is responsible for contacting the meter and reading out the needed values. Many older meters operate using this method. The challenging part is to handle the process of reading out meters when the meter population is very large.

Mixed architecture#

Most advanced metering infrastructures (AMI) have need for both pushing and polling operations. It is very lightweight on the head end system (Utilitarian) to have the meters to have normal operations run in a pushing architecture since we don't have to spend resources on polling the meters at fixed interval.

But there is always need for the ability to poll. For example we might be missing meter readings from an interval due to communication outage and need to get the values for invoicing. Then we most certainly need to poll the meter for the values. We might also want to read values that are not part of the normal push operations at certain intervals. For example: statistics about radio reception level. Other times we might need to write values to the meter, for example correcting time.

How Utilitarian handles AMR operations.#

Every meter reading that is collected is turned into a NewMeterReading message and put on the message queue. The Utilitarian API then receives the messages and saves it as meter readings in the database.

Pushing meters sends their meters readings to meter specific or protocol specific receivers that convert the data from the meter into NewMeterReading messages.

Polled meters are controlled via AmrTask. AmrTasks can be grouped in an AmrTaskGroup.

AmrTasks#

An AmrTask controls how a polling of a meter is done.

name

A unique name for the task

description

Longer description of the task

schedule

Decides on what schedule the task should be run. Time is in UTC!

  • quarterly, Task is run every 15 min, at 00, 15, 30 and 45.
  • hourly, Task is run every hour at 00
  • daily, Task is run every day at 00:00
  • weekly, Task is run every monday at 00:00
  • monthly, Task is run the 1st of every month at 00:00
  • yearly, Task is run the 1st of January at 00:00 every year
run_offet_seconds

If you are in another timezone than UTC you might want to run the task at different times than what is specified in the schedule. Many meters also have a slight clock synchronisation error so a value for a 00:00 might not have been registered in the meter when Utilitarian want to poll it.

Setting the run_offset_seconds will enable you to delay the execution of the task for that amount of seconds. You can only set as many seconds as there is until the next run of the task. For example you can only delay a quarterly task maximum of 15 minutes.

Note

It is not guarenteed that your task will be executed at the specific time set. But it will not be executed before that time. It all depends on the workload of the workers.

meter_execution_type

Decides in what execution context the task should run. Utilitarian has a number of implemented meters exeution contexts that can be used. Example: generic_lis200

task_call

In the specified meter execution context there will be a number of available calls to make to the meter. Example: set_time, read_archive_by_offset_seconds

task_kwargs

For every task_call there might be some additional info needed to run the task. These are supplied as key value arguments in the task_kwargs field. Example for task_call=read_archive_by_offset_seconds -> {"offset_seconds": 1000, "archive_number": 3, "control_position": 3}

AmrTaskGroups#

Several AmrTasks can be grouped together in an AmrTaskGroup. This is useful for managing all the different tasks for a specific meter type.

Connecting to Meter Devices#

Meter Devices can have several AmrTaskGroup connected to it via the task_groups field. This should be the normal operation of managing tasks for a meter.

But sometimes you might want to do some extra tasks on specific meters and then it is possible to add tasks via the meter_tasks field. Tasks defined there will only run for that meter.

Direct invocation#

It is possible to invoke a task directly via the API. No AmrTask is saved in the database but the same arguments are used. There tasks will be sent to the amr.on_demand queue and it is recomended to run a separate worker for this queue if you want the results fast.

Example:

{
    "meter_device": "890b61bb-6594-48db-ad90-584d56754455",
    "task_call": "read_archive_by_offset_seconds",
    "task_kwargs": {
        "offset_seconds": 1000,
        "archive_number": 3,
        "control_position": 3
    },
    "run_offset_seconds": 0,
    "meter_execution_type": "generic_lis200"
}