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How to safely shut down a 10Micron mount controller on power loss

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#1 Tonk

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Posted 20 May 2019 - 08:57 PM

My 10Micron mount is now installed in a remote location and will shortly be powered using solar arrays and storage batteries. With this sort of set up and 25 other users on the site vying for power there is always a possibily that power might run out. There is always a risk that a sudden unexpected power loss on an embedded computer may corrupt stored data (such as mount pointing models) or even the firmware. For this reason I interfaced a minature uninteruptible power supply (OpenUPS2) to monitor and control the 10Micron mount

See my photo blog here.

get.jpg?insecure

I'll update this based on any comments posted in this thread.

TIA - enjoy - Tonk smile.gif


Edited by Tonk, 21 May 2019 - 02:48 AM.

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#2 Arie

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Posted 22 May 2019 - 06:56 AM

Smart solution Tony.

Took a lot of thinking apparently.

 

I still wonder if there isn't another way to send a "shut down" command to the mount.

The programmers from MW and MC are able send instructions to mount from their applications.

 

I am told . . . that a proper UPS can shut down computers fed by them. So a command must be send to the computer telling it to shut down nice and easy.

As part of this instruction, isn't it possible to send  a "shut down" instruction to the mount as well?

You want the roof or dome to be closed too isn't it.

 

Or am I just dreaming?



#3 Tonk

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Posted 22 May 2019 - 09:55 AM

So a command must be send to the computer telling it to shut down nice and easy

 

Yes there is a shutdown command you can send the 10 Micron controller via the comms link (RS232 or LAN or WiFI). The shut down function is also on the handset. But ....

...  if you think a bit about this you need a functioning (i.e. non power compromised) computer, viable communications and stable software to manage this. My solution is stand-alone and works without this added interaction complexity. The complexity includes an ethernet hub or wireless access point that also needs to continue to be working during power loss. The main problem in a hosted facility is network switches and wifi access points are not under my control - I cant trust that they too are powered via a UPS - and if so - for long enough. The main computer/ethernet hub/wifi AP  can be dead at this point and I'm still going to get my 10Micron safely shutdown. I win smile.gif

In fact I have a separate OpenUPS2 set at 19 volts guarding the main NUC computer  - but the interfacing for that is straightforward and simple. The OpenUPS2 board was designed to sit inside a spare unused disk bay in a desktop computer and connect up its USB and shutdown ports via mother board headers. So I do the same with the NUC - except the USB gets connected via a regular spare USB port and the shutdown header is wired to an external jack with the wires going through a ventilation slot on the NUC.

My two lightweight mini UPS with small batteries only guard the computers as they risk becoming unbootable or corrupted if power is lost at a critical point. Cameras, filter wheels, focusers etc. are just sent to the dogs - they just loose power. They are designed to be powered down at any point so I don't need to treat them in a special manner.

As for the roll-off roof - that's not my problem (and cant be) as its managed by the hosting facility via its safety tools (weather station, weather rules and its own - heavy duty - UPS)

I am able to respond to the NUC computers's UPS switching to batteries event via the OpenUPS2 monitor software - so I can do simple things such as shut lens caps (they are USB powered via the NUC) but not much more.
 

 

Took a lot of thinking apparently.


Not that much ... there is a 3 year old thread on CN were various options for non-invasive interfacing to the 10Micron was discussed - so it was collective help

 

 

 

I am told . . . that a proper UPS can shut down computers fed by them.


Yes - there are two main ways 1) via monitor software running on the computer being protected - the software talks to the UPS via a USB link and can shut itself down in response to UPS events 2) via hardware - cable from UPS to the shutdown port found on most (if not all) computer motherboards. In the latter case its the UPS firmware and user set parameters that is in control.

Note in the case of the 10Micron the ideal solution is to have this UPS monitor software running on the 10Micron mount computer - not on some other computer that the UPS is not protecting. However 10Micron control what software gets loaded on the embedded Linux so I dont know if you can add your own independently.  Ivan has seen this hardware solution of mine at Astrofest last Feb and he took an interest and photos.


Edited by Tonk, 22 May 2019 - 12:15 PM.

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#4 Arie

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Posted 22 May 2019 - 11:38 AM

Thanks for the elaborate explanation Tony.

To be  honest, power-failures are very rare where I live.

But I want to investigate if it is wise to be better safe than sorry.

If, as 10M explains on their forum, a powercut causes no harm to the control box, maybe I shouldn't worry to much.

The little NUC computer running Win10Pro might be more sensitive for such an event.

That's where a lot of software runs and where the recent exposures sit.

I guess it would be wise to have thes stored on a external USB drive anyway?



#5 Tonk

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Posted 22 May 2019 - 12:34 PM

I guess it would be wise to have these stored on a external USB drive anyway?


Yes all my images are saved from camera directly to a 0.5 TB SSD USB stick.
 

 

If, as 10M explains on their forum, a powercut causes no harm to the control box, maybe I shouldn't worry to much.


Yes that's a claim. However there are suspected cases that volatile data can get corrupted - but it might be the case that the power loss happened at the point new data was being saved - such as in the middle of model building. I've had my GM2000 control box in an unbootable state a couple of years back due to a suspected power glitch and it had to go back to have the firmware reloaded - however the cause of this was never proven by 10Micron - other than I had accidentally pulled out the 24v power connector and it did not reboot after this!!  So I'm not taking the risk of an un-bootable system again smile.gif . The hosting facility has already suffered power loss and brown outs (especially when they were using an arc welder the week I was installing the rig there - the small scattering of houses in the neighborhood all had house lights that flickered in unison while this was going on!). The facility are adding solar power and storage batteries next month as the local electricity supply is rather variable and noisy


Edited by Tonk, 22 May 2019 - 01:01 PM.

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