Loosing Time

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f.fallon
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Re: Loosing Time

Post by f.fallon »

lukas wrote: 08 Mar 2018, 13:16 We recommend using timedatectl(1) as this will set the system clock and also synchronize the system clock back to the RTC in one go. Example:

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sudo timedatectl set-time "2018-03-08 13:15:00"
Thank you Lukas.
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volker
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Re: Loosing Time

Post by volker »

Batteries are not good for industrial devices as they would result in planned obsolescence or you would need a different casing which allows battery replacement. This is why we had decided to build in the much more expensive gold cap to guarantee a long lifetime of the system.
I cannot really think of a typical use case where you would need more then several hours of powerless state in industrial applications. Most cabinets are under current even over the night or during weekends even if the machines are switched off. Therefore the typical use case is a mains power failure which in most countries of the world will not be longer than several minutes or up to some hours. In a case of major power failures due to catastrophic damage (like actually in some US cities due to storms) customers will have huger problems than resetting their RTC during healing phase of such events.
So: No we do not have such plans as we can't see a relevant amount of use cases which would need more than 48 hours backup time. But if you can convince us by showing us such use cases we might consider designing solutions for the next revision.
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KarlZeilhofer
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Re: Loosing Time

Post by KarlZeilhofer »

I think we could put a real time clock chip by default on the makerboard, there is still some place on the board left. But we plan the fist small batch in the beginning of May. So you have to be a bit patient.
f.fallon
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Re: Loosing Time

Post by f.fallon »

volker wrote: 09 Mar 2018, 10:31 Batteries are not good for industrial devices as they would result in planned obsolescence or you would need a different casing which allows battery replacement. This is why we had decided to build in the much more expensive gold cap to guarantee a long lifetime of the system.
I cannot really think of a typical use case where you would need more then several hours of powerless state in industrial applications. Most cabinets are under current even over the night or during weekends even if the machines are switched off. Therefore the typical use case is a mains power failure which in most countries of the world will not be longer than several minutes or up to some hours. In a case of major power failures due to catastrophic damage (like actually in some US cities due to storms) customers will have huger problems than resetting their RTC during healing phase of such events.
So: No we do not have such plans as we can't see a relevant amount of use cases which would need more than 48 hours backup time. But if you can convince us by showing us such use cases we might consider designing solutions for the next revision.
One use case is once a year our customer does an electrical shutdown for several days so 48 hours wouldn't be sufficient. Also they could be shutting down machines for maintenance so the downtime could be unpredictable.
KarlZeilhofer wrote: I think we could put a real time clock chip by default on the makerboard, there is still some place on the board left. But we plan the fist small batch in the beginning of May. So you have to be a bit patient.
Hi Karl, If you could do that, that would be great. I understand could you put us on the list to get one of those boards?
Rob65
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Re: Loosing Time

Post by Rob65 »

volker wrote: 09 Mar 2018, 10:31 Batteries are not good for industrial devices
Although I tend to agree, the industry shows a different opinion.
We have a Fanuc Robot which has a battery pack with 4 AA cells to store calibration data. The controller of my Bridgeport VMC1000 (CNC milling center) uses 2 AA cells as a backup for the RTC and the old System 5 Siemens PLCs that take up most of the wall in our switching room uses batteries for the battery backuped RAM.

In all cases, these batteries are easily replaceable and the maintenance manuals contain information on how to do this while the system is powered to prevent loss of data.
For the RTC used in the RevPi Core, you could even go for a Lithium Thionyl Chloride battery. A 1/2 AA size 3.6V battery of this type needs to be replaced only once every 10 years.

I think I might try to upgrade my RevPi3 when it arrives :-)

Rob
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volker
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Re: Loosing Time

Post by volker »

S5? Bridgport VMC1000? I was talking about 21st centuries industry ;-)
Sorry, just kidding. But the reality is 9 out of 10 modern systems will not use batteries and there are many reasons for it. But the most important reason is: RevPi is aiming to the I 4.0 and IoT gateway market and even if used as a PLC most of the customers are connecting the device to a network. So most of the time there is no problem to reach a time server. But there would have been immense problems in a world wide distribution of a system using fixed built in Lithium battery technique. Try and find out yourself the regulations for shipping such items...
The other restrictions we needed to take into account when constructing the RevPi Core were the facts that the case was predefined to be able to use all our industrial gateways which already existed when we started the project. So no way to get any replaceable batteries plus lid in this case.
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Rob65
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Re: Loosing Time

Post by Rob65 »

volker wrote: 13 Mar 2018, 15:18 The other restrictions we needed to take into account when constructing the RevPi Core were the facts that the case was predefined to be able to use all our industrial gateways which already existed when we started the project.
"Being stuck" with the beautiful design of the case is a good reason to not include a battery. The case is so attractive that I bought an extra maker set just to put some of my own electronics in there :D
I am not sure it there is room for a battery but I'll give it a try as soon as my RevPi Core arrives.
The first application is as a machine controller for a robot system drilling holes in aluminium rims. That machine will most likely be switched of regularly and not be on (or online) for multiple days. A larger backup for the RTC or possibly even a backup for the complete RevPi Core would be great.

And yes - the S5 was indeed a joke. The only reason why it is still being used is because there is nobody around who knows how this thing is intertwined with our ventilation system :shock:

I'l keep you informed about my progress.
f.fallon
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Re: Loosing Time

Post by f.fallon »

volker wrote: 13 Mar 2018, 15:18 S5? Bridgport VMC1000? I was talking about 21st centuries industry ;-)
Sorry, just kidding. But the reality is 9 out of 10 modern systems will not use batteries and there are many reasons for it. But the most important reason is: RevPi is aiming to the I 4.0 and IoT gateway market and even if used as a PLC most of the customers are connecting the device to a network. So most of the time there is no problem to reach a time server. But there would have been immense problems in a world wide distribution of a system using fixed built in Lithium battery technique. Try and find out yourself the regulations for shipping such items...
The other restrictions we needed to take into account when constructing the RevPi Core were the facts that the case was predefined to be able to use all our industrial gateways which already existed when we started the project. So no way to get any replaceable batteries plus lid in this case.
Hi Volker for all our customers, that will not be the case, the factory floor is totally separated from the IT side (so that nobody can interfere with the production line) so connecting to the internet to talk to a time server is not always going to be possible. We have an IOT device from Siemens, the IOT2040 and guess what? There is a built in replaceable RTC battery!. Why not an add-on unit for RTC which its sole purpose is for RTC and have an accessible battery built in? I would purchase this, right now if there was an out of the box RTC that would work with this device (without the need for development of a driver etc..) :).

On a side note even if this was a larger cap that could hold the time for a few weeks that might not be as bad as a S7 1200 can hold its time for up to 20 days.
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Truos
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Re: Loosing Time

Post by Truos »

Maybe you could setup one unit with an outside antenna and get time via GPS and then have an internal Timeserver?
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Truos
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Re: Loosing Time

Post by Truos »

Hello,

I know it was some time since you posted this but could you setup one RevPi as a NTP-server locally and have it sync it's time from GPS with an external antenna?

That way you will have a secure time server on your network.
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