Revisited: Auto Boot from power off - inconsistent operation

[aoloufa]

Yes, I realize that was explained elsewhere but this feature does not work consistently which is a major problem for us.

All our installations are remote and a major requirement is the ability to recycle power to the machine and have it reboot.

Our Odroid 3H+ is brand new and the Bios has been setup for S0 (reboot after power failure). After setting it up, we tried it and it worked as expected. However, after the machine was working for about a week, we recycled power but in this case, the machine NEVER came back which required us to go to the site to fix it. At the site, we found that the machine was off and did not restart when we recycled power!

We then unplugged the power supply from the receptacle, waited 10 seconds then plugged it back in. That is when the machine started again. Why did this happen?

I hope this can be resolved because if this problem cannot be fixed, we will regrettably have to drop this hardware all together.

If is helps, the machine is powered from a 24V power supply which powers a 24 VDC - 19VDC converter which in turn powers the Odroid H3+.

Thanks in advance to the community for your help.

[odroid]

Yes, I realize that was explained elsewhere but this feature does not work consistently which is a major problem for us.

All our installations are remote and a major requirement is the ability to recycle power to the machine and have it reboot.

Our Odroid 3H+ is brand new and the Bios has been setup for S0 (reboot after power failure). After setting it up, we tried it and it worked as expected. However, after the machine was working for about a week, we recycled power but in this case, the machine NEVER came back which required us to go to the site to fix it. At the site, we found that the machine was off and did not restart when we recycled power!

We then unplugged the power supply from the receptacle, waited 10 seconds then plugged it back in. That is when the machine started again. Why did this happen?

I hope this can be resolved because if this problem cannot be fixed, we will regrettably have to drop this hardware all together.

If is helps, the machine is powered from a 24V power supply which powers a 24 VDC - 19VDC converter which in turn powers the Odroid H3+.

Thanks in advance to the community for your help.

We couldn't reproduce the problem if we configured the G3 state option correctly as this wiki page.
https://wiki.odroid.com/odroid-h3/appli ... er_applied

I have a couple of questions to narrow down root causes.
Can you tell me more about "we recycled power"?
Do you remotely turn off and on the 24V-to-19V DCDC converter? or whole 24Volt power source?
Can you adjust(increase) the period of off-state time to one minute? A too fast on-off-on cycle might make a unstable status of G3 - S0 transient in some edge conditions.
Can you measure the actual voltage of the 19V power rail in the off-sate to check whether it is true zero volt or not?
What is the maximum output power from the DCDC converter?

[aoloufa]

Thank you very much for your prompt response, I appreciate it.
Please see below the answers to your questions.

--------------------------------------------
"Do you remotely turn off and on the 24V-to-19V DCDC converter? or whole 24Volt power source?"
Because the unit is remote, we first recycled power to the 24V DC power supply. This did not work and the unit never restarted.
When we went to the site, we disconnected the DC plug that is powering the H3 from the 24-19V supply. When we reconnected it, the unit started.
--------------------------------------------
"Can you adjust(increase) the period of off-state time to one minute? A too fast on-off-on cycle might make a unstable status of G3 - S0 transient in some edge conditions."
How can this be done?
--------------------------------------------
"Can you measure the actual voltage of the 19V power rail in the off-sate to check whether it is true zero volt or not?"
Yes, we did measure it after we disconnected the plug from the H3. It was supplying 19V according to our meter.
--------------------------------------------
"What is the maximum output power from the DCDC converter?"
We are using a 24V-19V converter. It outputs 19V at 5A.
Here is the unit we are using:
http://www.amazon.com/uxcell-Converter- ... B01H97ETVM

[odroid]

My assumption was wrong.
I thought the DCDC converter has an enable/disable control pin which could be remotely controlled by you.
But the DCDC in the amazon link has no control function.

Anyway,
When you performed a power cycle event, how long did you turn off the 24V power supply and wait before turning it back on?
You need to keep measuring the voltage of 19Volt output from the DCDC converter when you turn off the 24V DC power supply.
This is because if the power is turned on again before the energy remaining in the two stage power supplies is fully discharged and reaches 0Volt, there is a high probability that automatic start will not operate properly.

[aoloufa]

Earlier, I thought this may have been the issue so I turned the 24V power supply off for a few hours first. When power to the 24V supply was back on, the H3 never restarted. I will try again next week because the PC is a 2-hour drive away.

Is this the correct process for recycling power?

1) Power the 24VDC supply off.

2) Wait one minute

3) Power the 24V PS back on

-----------------------------------------------

To avoid this issue all together, will the Odroid H3+ work directly from a 24V supply or is it limited to 19V? IF it will work with 24V, what current is needed?

Thanks

[L67GS]

Could you use a contactor in the design? The coil would be across the 24V bus, and the contacts would close the 19V to the H3 giving it a more finite off state.
The drawbacks being the contactor would be wasting power and could produce unwanted rf noise.

[odroid]

Earlier, I thought this may have been the issue so I turned the 24V power supply off for a few hours first. When power to the 24V supply was back on, the H3 never restarted. I will try again next week because the PC is a 2-hour drive away.

Is this the correct process for recycling power?

1) Power the 24VDC supply off.

2) Wait one minute

3) Power the 24V PS back on

-----------------------------------------------

To avoid this issue all together, will the Odroid H3+ work directly from a 24V supply or is it limited to 19V? IF it will work with 24V, what current is needed?

Thanks

If possible, it would be safer to wait for about 10 minutes.

No, the maximum input voltage is limited at 20Volt. If you connect it to 24 volts for a long time, the circuit components will likely be damaged.

[aoloufa]

Thank you for the responses.

I am not knowledgeable about electronics but have a suspicion: When the 24Vdc power supply is disconnected, maybe the 24V - 19V converter keeps its charge for a while making the Odroid H3 think it is powered?

Is there a circuit which would kill any remaining charge in the 24V - 19v converter?

I never had this problem in over 20 years tinkering with PCs. The ability to recycle power remotely is a must when operating remote systems. I really like the H3+ but this problem unless ultimately resolved is a show stopper.

[aoloufa]

Could you use a contactor in the design? The coil would be across the 24V bus, and the contacts would close the 19V to the H3 giving it a more finite off state.
The drawbacks being the contactor would be wasting power and could produce unwanted rf noise.

Thank you for helping me.

What is a "contactor"

[odroid]

Thank you for the responses.

I am not knowledgeable about electronics but have a suspicion: When the 24Vdc power supply is disconnected, maybe the 24V - 19V converter keeps its charge for a while making the Odroid H3 think it is powered?

Is there a circuit which would kill any remaining charge in the 24V - 19v converter?

I never had this problem in over 20 years tinkering with PCs. The ability to recycle power remotely is a must when operating remote systems. I really like the H3+ but this problem unless ultimately resolved is a show stopper.

Have you already tried waiting 10 minutes before turning on 24V PSU?
Is the problem still existing?

If yes, please use a multimeter to measure the voltage at the power input terminal of the H3+.
You need to know how long it takes for the voltage at the power input terminal of the H3+ to reach 19 to 0 volts after removing the power from the 24-volt power supply before you can find a solution.
I don't know what the power input voltage range of the PCs you have used over the past 20 years was, but if you used the same DCDC converter, you might experience similar symptoms.

[aoloufa]

"You need to know how long it takes for the voltage at the power input terminal of the H3+ to reach 19 to 0 volts after removing the power from the 24-volt power supply before you can find a solution."

OK, will try next time I go to the site as it is several hours away.

So let us say it takes 3 minutes (random example) to go from 19V to 0, how can this information be used to solve the problem?

[L67GS]

Could you use a contactor in the design? The coil would be across the 24V bus, and the contacts would close the 19V to the H3 giving it a more finite off state.
The drawbacks being the contactor would be wasting power and could produce unwanted rf noise.

Thank you for helping me.

What is a "contactor"

A contactor is a relay, but more industrial.

[odroid]

So let us say it takes 3 minutes (random example) to go from 19V to 0, how can this information be used to solve the problem?

You turn off the 24-volt power supply, must wait 3 minutes at least, and then turn it back on.


BTW, I ordered a similar(looks exactly same) 19V/5A DCDC converter from China since we have no direct access to Amazon in Korea.
https://www.aliexpress.com/item/1005003856921085.html
It may take a couple of weeks to get it. Once we receive it, we will try reproducing the issue.

[aoloufa]

Thank you for your service. I appreciate it.

[aoloufa]

What is a "contactor"
[/quote]

A contactor is a relay, but more industrial.
[/quote]

Thank you. We have a lot of solid state relays.

Here is what I do not understand. Even if a relay is used, if the converted 19V does not decay quickly, the relay will stay on until that potential is gone. So how will the contactor/relay help in this case?

[L67GS]

What is a "contactor"

A contactor is a relay, but more industrial.
[/quote]

Thank you. We have a lot of solid state relays.

Here is what I do not understand. Even if a relay is used, if the converted 19V does not decay quickly, the relay will stay on until that potential is gone. So how will the contactor/relay help in this case?
[/quote]

That depends largely on what your voltage drops to in the off state, if it's a significant amount there won't be enough to keep the coil energized. I would not use a SSR for something like this though. And the coil should have a diode to catch any spikes when the field in the coil collapses.
Also this method would be controlled by the 24v, and break the 19v so any capacitance in that voltage regulator would be irrelevant.