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soft power-off for USB controllers

Posted: Sun May 08, 2011 3:08 pm
by giorae
Hi,

I currently use another kind of thin client and want to migrate to the fitPC.

We run our systems on remote sites, and can't service them frequently, therefore we need them to be very reliable.
From our experience some USB peripherals such as GSM modems sometimes fail, and the only way to resume normal operation is to disconnect the power that they receive through the USB port and reconnect it (this can be simply done by plugging the USB cable off of plugging the computer's powercord off and then connecting it again). The problem is that this cannot be done remotely.

I wanted to ask if the fitPC can power off its USB ports in software. Some ways that I thought that could do it (please let me know if any of these is possible):
(1) putting the system into sleep mode and then waking it up on a timer (does sleep/standby mode powers off the USB ports? Can the computer resume automatically from a sleep state?)
(2) Shutting down the system and using a BIOS wake-on-time feature (I think the forum says that it is not available in the FitPC, is it?)
(3) some software code that can actually power off the USB and then power it on.

BTW - we usually use ubuntu 9.04 (but can upgrade to any version).

Thanks in advance,

Giora

Re: soft power-off for USB controllers

Posted: Mon May 16, 2011 11:02 am
by Denis
Hi,
The answer depends on fitPC type you are using: fitPC2 or fitPC2i

fitPC2 powers off it`s USB ports when goes itself to power-off state. In suspend state USB ports are still powered. So you will need to power off fitPC2 and then power it on after about 10-15 seconds. You can do it using watchdog mechanism. If you interested I can give some tips to more clear and reliable "reboot" process.

fitPC2i powers on it`s USB ports constantly, in both power-off and suspend states. You will need physically unplug the power cord and plug in again.

There is no software that can control USB power supply.

Re: soft power-off for USB controllers

Posted: Tue May 17, 2011 7:31 pm
by giorae
Thanks Dennis,

1. So in this case I need to be the fitPC2 which enables what you described. I just wanted to make sure that the process you suggested to reboot including powering off the USB for 10 seconds can be done remotely in a reliable way without physical intervention , and. An be implemented in ubuntu.
2. In addition I just wanted to make sure that the fitpc2 knows to power-on if there is a power outage and then the power resumes (we need this since the computer in a remote site and nobody can manually turn it on)

If there is appsitive answer to the questions above I will be able to buy the fitpc2 for our purposes.

Thanks,

Giora

Re: soft power-off for USB controllers

Posted: Thu May 19, 2011 10:56 am
by Denis
1. Yes. However it will require small kernel patch. Install LinuxMint9/Ubuntu10.04 as described on our wiki/forum, I will send you updated watchdog file and instructions how to use it.

2. Yes. This feature exists in fitPC2.

Re: soft power-off for USB controllers

Posted: Wed May 25, 2011 8:49 am
by giorae
Thanks again Dennis - I will get my fitpc2 tomorrow and install Ubuntu.

Can you send me the kernel patch and/or watchdog? My email is <giora@meterlive.com>. Any documentation that you have will also help.

How do I then perform the automatic power on and power off?