Restart after power loss

Chris Malcolm wrote:
> Johan St?ck <johan DeleteThis @stack.se> wrote:
>> Hello!
>
>> I am experimenting with time-lapse over a long time-scale (years)
>> I will deploy digital still cameras that will be controlled by a
>> computer. Tne pictures will be transmitted to a central location using
>> 3G mobile.
>
>> The computer and the camera control software restarts after a power loss.
>> However, I am a bit worried over the behaviour of the cameras.
>> The cameras will be powered from a AC adapter.
>> The Olympus cameras that I have been trying out will evidently not power
>> up automatically when power is restored.
>> You have to push the "power" button.
>> This is not good if the camera is several hours drive away....
>
>> Is there anyone with knowledge about other brands of cameras?
>> That is: when powered via an AC adapter, does the camera restart after a
>> power loss?
>
> Why not power the camera from a power supply with battery backup in
> the event of a power failure? Cheaper than getting new cameras, and
> extremely cheap if you don't mind using non-rechargeable batteries and
> checking them out once a year or so.

Hey, I was gonna suggest that!

Although I was thinking of a standard SOHO-grade UPS, like an APC or
Belkin... a basic 350VA APC model lists for CDN$70 at Staples, for
example, and should run your camera(s) for several hours. A larger one
will keep your computer AND camera(s) going for a fair time period. For
that matter, using a laptop and a 650-750VA UPS will allow the whole rig
to keep going for hours without line power. You could probably get a
used PII/PIII laptop (which would be more than sufficient for a
dedicated machine for this purpose) for under $200.
 >> Stay informed about: Restart after power loss 

Johan Stäck wrote:
> Hello!
>
> I am experimenting with time-lapse over a long time-scale (years)
> I will deploy digital still cameras that will be controlled by a
> computer. Tne pictures will be transmitted to a central location using
> 3G mobile.
>
> The computer and the camera control software restarts after a power loss.
> However, I am a bit worried over the behaviour of the cameras.
> The cameras will be powered from a AC adapter.
> The Olympus cameras that I have been trying out will evidently not power
> up automatically when power is restored.
> You have to push the "power" button.
> This is not good if the camera is several hours drive away....
>
> Is there anyone with knowledge about other brands of cameras?
> That is: when powered via an AC adapter, does the camera restart after a
> power loss?
>
> I am particularly interested in info about Canon and Nikon cameras,
> since there are SDK:s (software allowing computer control) available for
> them (as there also is for Olympus).
>
> Tia,
>
> /Johan Stäck
> Skellefteå
> Sweden
One word UPS!
 >> Stay informed about: Restart after power loss 

On Wed, 27 Feb 2008 18:18:00 -0600, Ron Hunter wrote:

> One word UPS!

ITYM: "One acronym: UPS!"
 >> Stay informed about: Restart after power loss 

Allodoxaphobia skrev:
> On Wed, 27 Feb 2008 18:18:00 -0600, Ron Hunter wrote:
>
>> One word UPS!
>
> ITYM: "One acronym: UPS!"
Well, a UPS will be to bulky to fit into the camera housings that I plan
to use.

However, I have ordered a small sealed led-acid battery and suitable
trickle-charger.
I will use them (together with a voltage regulator feeding the camera)
to always keep the camera powered.

I really don't mind the PC restarting now and then.
(And, it *will* restart)
Might even do some good...

/Johan
 >> Stay informed about: Restart after power loss 

Johan Stäck wrote:
> Allodoxaphobia skrev:
>> On Wed, 27 Feb 2008 18:18:00 -0600, Ron Hunter wrote:
>>
>>> One word UPS!
>>
>> ITYM: "One acronym: UPS!"
> Well, a UPS will be to bulky to fit into the camera housings that I plan
> to use.

That's why the computer and UPS go in a separate enclosure... or do you
plan on cramming the PC into the camera housing as well?

> However, I have ordered a small sealed led-acid battery and suitable
> trickle-charger.
> I will use them (together with a voltage regulator feeding the camera)
> to always keep the camera powered.
>
> I really don't mind the PC restarting now and then.
> (And, it *will* restart)
> Might even do some good...

A sharp power-down won't though. If the power fails while the computer
is in middle of a disk access, it's possible (not likely, but possible)
to have file corrupted or worse, an unstartable system... or ultimate
worst-case, damaged hardware. A power SURGE or brownout is even more
likely to do damage.
 >> Stay informed about: Restart after power loss 

Johan Stäck <johan RemoveThis @stack.se> wrote:
>
>The problem is that all cameras these days have USB ouput.
>It will be diffucult to have the PC and the camera more than a couple of
>meters apart, due to USB cable length restrictions.
>So, I plan on having them in the same enclosure.

The specifications for USB cable length are for powering
a remote device at the maximum load current allowed.
That is a relatively short distance. Of course if you
are not powering the device from the USB port, the
distance over which data can be sent is significantly
longer!

I wouldn't doubt that it would work at some significant
distances, but for a unmanned remote it probably should
be limited to a few meters. Hence, if the camera is on
a tower adjacent to a building, go for it. If it is in
a building 30-40 meters away... that's likely too far.

>However, I will certainly consider having a UPS standing at some
>distance from the camera/PC enclosure.
>
>> A sharp power-down won't though. If the power fails
>> while the computer is in middle of a disk access, it's
>> possible (not likely, but possible) to have file
>> corrupted or worse, an unstartable system... or
>> ultimate worst-case, damaged hardware. A power SURGE
>> or brownout is even more likely to do damage.
>
>True, but when running NTFS, I think that the risk is rather small.
>
>But, if possible I will try and install a UPS at ground level.
>The cameras will mostly be placed high.

For remote operation there are two design points that
need to be given high priority. One is KISS, or Keep It
Simple Stupid. The more stuff you add, the more likely
it will break. Another point is that spending extra on
the highest quality equipment will pay off in the long
run. (I'm used to dealing with situations where it
might cost $2000 to get a technician on site; hence
spending a few extra thousands initially pays off very
well over a period of years.)

One piece of equipment that has not been mentioned,
which can be put to very good use, is a modem controlled
AC power distribution unit. Say 10 AC outlets, each of
which can be turned on and off remotely via the modem.
That allows you to "reset", individually, each piece of
equipment, and do it in the order you choose. It could
also be arranged to have one outlet trigger a mechanical
device to physically push a button on a camera too!

That device will correct about 99% of all "problems"!

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd RemoveThis @apaflo.com
 >> Stay informed about: Restart after power loss 

Matt Ion skrev:

>
> That's why the computer and UPS go in a separate enclosure... or do you
> plan on cramming the PC into the camera housing as well?
>
Yes, PC:s can be really small these days (google for pico_ITX..)
The PC can actually be about the size of the camera!
The PC I am using now is 17*12*5 cm.

The problem is that all cameras these days have USB ouput.
It will be diffucult to have the PC and the camera more than a couple of
meters apart, due to USB cable length restrictions.
So, I plan on having them in the same enclosure.

However, I will certainly consider having a UPS standing at some
distance from the camera/PC enclosure.

>
> A sharp power-down won't though. If the power fails while the computer
> is in middle of a disk access, it's possible (not likely, but possible)
> to have file corrupted or worse, an unstartable system... or ultimate
> worst-case, damaged hardware. A power SURGE or brownout is even more
> likely to do damage.
True, but when running NTFS, I think that the risk is rather small.

But, if possible I will try and install a UPS at ground level.
The cameras will mostly be placed high.

/Johan
 >> Stay informed about: Restart after power loss 

On Sun, 02 Mar 2008 17:54:27 +0100, Johan Stäck <johan RemoveThis @stack.se>
wrote:

>Matt Ion skrev:
>
>>
>> That's why the computer and UPS go in a separate enclosure... or do you
>> plan on cramming the PC into the camera housing as well?
>>
>Yes, PC:s can be really small these days (google for pico_ITX..)
>The PC can actually be about the size of the camera!
>The PC I am using now is 17*12*5 cm.
>
>The problem is that all cameras these days have USB ouput.
>It will be diffucult to have the PC and the camera more than a couple of
>meters apart, due to USB cable length restrictions.
>So, I plan on having them in the same enclosure.

If for some reason you needed them further apart than a USB cable
could handle (sounds like you don't, but if you did) you can always
link them together wirelessly. I don't know what kind of camera
you're using but if it's a higher end one, then there's probably a
wireless controller available for it. Something like the Nikon WT-1a,
2a, 3a or 4a depending on the Nikon model.

Steve
 >> Stay informed about: Restart after power loss 

In article <rbqls3l6826e6886vsis0q62v8rngossi9 RemoveThis @4ax.com>, Steve
<steve RemoveThis @example.com> wrote:

> If for some reason you needed them further apart than a USB cable
> could handle (sounds like you don't, but if you did) you can always
> link them together wirelessly. I don't know what kind of camera
> you're using but if it's a higher end one, then there's probably a
> wireless controller available for it. Something like the Nikon WT-1a,
> 2a, 3a or 4a depending on the Nikon model.

and if it takes an sd card, add wireless with an eye.fi card.
 >> Stay informed about: Restart after power loss 

floyd.DeleteThis@apaflo.com (Floyd L. Davidson) wrote:
>The specifications for USB cable length are for powering
>a remote device at the maximum load current allowed.
>That is a relatively short distance. Of course if you
>are not powering the device from the USB port, the
>distance over which data can be sent is significantly
>longer!

Actually the signal round-trip time from host to device and back is a
limiting factor, too. Using the maximum number of chained hubs this comes
down to about 5m maximum cable length.
If you are using fewer hubs, then yes, you can increase the cable length
further, but at the cost of degrading the signal quality. At some point it
just won't work any longer.

There are better options which transfer the USB signal on CAT5 cables (max
length 50m) or fibre optic (up to 10km).

jue

>
>I wouldn't doubt that it would work at some significant
>distances, but for a unmanned remote it probably should
>be limited to a few meters. Hence, if the camera is on
>a tower adjacent to a building, go for it. If it is in
>a building 30-40 meters away... that's likely too far.
>
>>However, I will certainly consider having a UPS standing at some
>>distance from the camera/PC enclosure.
>>
>>> A sharp power-down won't though. If the power fails
>>> while the computer is in middle of a disk access, it's
>>> possible (not likely, but possible) to have file
>>> corrupted or worse, an unstartable system... or
>>> ultimate worst-case, damaged hardware. A power SURGE
>>> or brownout is even more likely to do damage.
>>
>>True, but when running NTFS, I think that the risk is rather small.
>>
>>But, if possible I will try and install a UPS at ground level.
>>The cameras will mostly be placed high.
>
>For remote operation there are two design points that
>need to be given high priority. One is KISS, or Keep It
>Simple Stupid. The more stuff you add, the more likely
>it will break. Another point is that spending extra on
>the highest quality equipment will pay off in the long
>run. (I'm used to dealing with situations where it
>might cost $2000 to get a technician on site; hence
>spending a few extra thousands initially pays off very
>well over a period of years.)
>
>One piece of equipment that has not been mentioned,
>which can be put to very good use, is a modem controlled
>AC power distribution unit. Say 10 AC outlets, each of
>which can be turned on and off remotely via the modem.
>That allows you to "reset", individually, each piece of
>equipment, and do it in the order you choose. It could
>also be arranged to have one outlet trigger a mechanical
>device to physically push a button on a camera too!
>
>That device will correct about 99% of all "problems"!
 >> Stay informed about: Restart after power loss 

Jürgen Exner <jurgenex.RemoveThis@hotmail.com> wrote:
>floyd@apaflo.com (Floyd L. Davidson) wrote:
>>The specifications for USB cable length are for powering
>>a remote device at the maximum load current allowed.
>>That is a relatively short distance. Of course if you
>>are not powering the device from the USB port, the
>>distance over which data can be sent is significantly
>>longer!
>
>Actually the signal round-trip time from host to device and back is a
>limiting factor, too. Using the maximum number of chained hubs this comes
>down to about 5m maximum cable length.

Hubs are powered from the cable, and *that* is precisely
what I excluded in the discussion above.

Regardless, the latency due to length of a 5m of cable
isn't significant at the speeds USB 2.0 works at.

>If you are using fewer hubs, then yes, you can increase the cable length
>further, but at the cost of degrading the signal quality. At some point it
>just won't work any longer.

The point is that there are *no* hubs. And it was never
represented as a long haul mechanism.

>There are better options which transfer the USB signal on CAT5 cables (max
>length 50m) or fibre optic (up to 10km).

Off hand I'd say that over 10 meters, maybe a little
more, that would definitely be the appropriate solution.
That of course is just about exactly what I said
previously, as you've quoted below.

Regardless, the point is that the restriction the OP
mentioned is for power, not signal, distance over a
normal USB connection.

>>I wouldn't doubt that it would work at some significant
>>distances, but for a unmanned remote it probably should
>>be limited to a few meters. Hence, if the camera is on
>>a tower adjacent to a building, go for it. If it is in
>>a building 30-40 meters away... that's likely too far.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd.RemoveThis@apaflo.com
 >> Stay informed about: Restart after power loss