Polling?

[Josephny]

Not sure if this is a scripting question.

I want to be able to poll the UPS’s status.

Or, more generally, I want the router to do something if the line (input) voltage to the UPS drops below a threshold and/or the UPS has changed to battery power.

I have this code which seems to work, but I am hoping there is a way to do this without running the script every second.

:if (([/system/ups/monitor 0 once as-value]->"on-line") = "false") do={

  :local voltage (([/system ups monitor 0 once as-value]->"line-voltage")/100)
  :log info $voltage
}

Possible?

[Josephny]

It looks like there is no solution.

[Amm0]

Remove the “once” and it becomes a “:while (true)” loop, so it will run forever. There is an interval= that control how often the do={} code is run, i.e. 1s or 1m or 1h etc…

You can also make only run for a fixed period like duration=1m. This is useful like in a /system/scheduler script if say the schedule was “every 1m”, it just run the “monitor” loop, and end at same time as schedule. But you can just say once at =startup, and should keep running forever if you do not provide an duration= value.

[Josephny]

Remove the “once” and it becomes a “:while (true)” loop, so it will run forever. There is an interval= that control how often the do={} code is run, i.e. 1s or 1m or 1h etc…

You can also make only run for a fixed period like duration=1m. This is useful like in a /system/scheduler script if say the schedule was “every 1m”, it just run the “monitor” loop, and end at same time as schedule. But you can just say once at =startup, and should keep running forever if you do not provide an duration= value.

Interesting. This is a powerful, and potentially dangerous approach – (don’t ask me how I found out).

I used the following code (setting the condition tested to be “on-line” being true was just used for testing; depoloyed it would be false):

:local UPSonline ([/system/ups/monitor 0 once as-value]->"on-line")

:while ([/system/ups/monitor 0 once as-value]->"on-line") do={
    :log info $UPSonline
    :local voltage (([/system ups monitor 0 as-value]->"line-voltage")/100)
}

The only way I was able to get out of it was rebooting the router.

Does a continuously run “while” loop use a lot fo system resources?

I don’t see any documentation including “duration=” in the while loop.

Is there a more graceful way to get the while loop to stop?

Is this the recommended way to do this?

Thank you.

[rextended]

It’s quicker to set it in the scheduler every second rather than doing intricate things, especially for those who are not familiar with scripting…

[Josephny]

It's quicker to set it in the scheduler every second rather than doing intricate things, especially for those who are not familiar with scripting...

Does setting a scheduler for every second create a large CPU overhead?

[rextended]

Need to run Assassin’s Creed on your router?

Does setting a infinite loop for every nanosecond create a more large CPU overhead?

[Josephny]

Need to run Assassin's Creed on your router?

No.

Does setting a infinite loop for every nanosecond create a more large CPU overhead?

No idea.

[rextended]

Jokes aside, I don’t have any UPS directly connected to a RouterBOARD otherwise I would have helped you better,
but if you are not familiar with scripting the 1 second scheduler is more than enough and practically does not consume CPU.

[Josephny]

Jokes aside, I don't have any UPS directly connected to a RouterBOARD otherwise I would have helped you better,
but if you are not familiar with scripting the 1 second scheduler is more than enough and practically does not consume CPU.

Oh, how disappointing! I was hoping you were going to provide a tutorial for how to run Assasin's Creed on a hEX!

Seriously: Thank you.

[Amm0]

I should have been clearer, in all likelihood using the "monitor once" in a scheduler is a better plan.

I was more explaining how it works when NOT using "once"... generally speaking .

Jokes aside, I don't have any UPS directly connected to a RouterBOARD otherwise I would have helped you better,

Not wrong. I don't use UPS either.

I do know some stuff like LTE – which also uses "monitor" – may not actually get all value every time. For example, on some modems it's ~50% where the CQI or RSRQ will be included in "monitor once". The "loop" version of monitor for more like voltage over 10 seconds, i.e. "duration=10s interval=1s". But if you're just looking for just "on-line", then the no need to make it complex & and assuming UPS always report "on-line"... using once should be fine and then just scheduling it how ever often you want to check.

Let /system/scheduler manage the interval it checks with "once" is best plan.

[Josephny]

I do know some stuff like LTE – which also uses “monitor” – may not actually get all value every time. For example, on some modems it’s ~50% where the CQI or RSRQ will be included in “monitor once”. The “loop” version of monitor for more like voltage over 10 seconds, i.e. “duration=10s interval=1s”. But if you’re just looking for just “on-line”, then the no need to make it complex & and assuming UPS always report “on-line”… using once should be fine and then just scheduling it how ever often you want to check.

Let /system/scheduler manage the interval it checks with “once” is best plan.

Thank you again for the explanation.

I searched the entire ROS manual for “monitor once” as well as for “duration=” and could not find an explanation for the “once” or “duration=” parameters.

I am looking for both “on-line” as well as “line-voltage” – does that change the recommendation to use the scheduler and not use a duration parameter?

[Josephny]

Update:

At the location that prompted me to start this “voltage” investigation, I have frequent (but irregular – i.e., at random times) losses of internet connectivity. Sometimes it turns out the cable modem needs to be rebooted, and other times, service is restored without intervention in seconds or minutes.

When I used this ‘run-script-every-second’ solution I discovered that the line-voltage was dropping to as low as 106 from time to time.

The equipment are all connected to a UPS, but not a fancy one (i.e., not an on-line sine wave device).

I double checked the line voltage by monitoring a power usage I have set up for the entire location (Emporia Vue) and confirmed the low voltage.

I called the electric utility company, they came out yesterday, and now the voltage to the entire house is steady at 122 (with an occasional dip to 119).

I don’t know yet if this will solve the problem, but it definetly helped solve another problem (that I did not know I had).