Author Topic: Problem in safe mode of SBC65EC  (Read 4172 times)

AlexKots

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Problem in safe mode of SBC65EC
« on: November 20, 2012, 05:57:56 PM »
I have 16 SBC65ECs, HW V 3.20, SW V 3.10.

Trying the first one and changing some parameters, after rebooting the device it stopped responding.
I tried safe mode, the LED was blinking properly, but still no communication was possible.
Ethernet LEDs were working properly.
It failed also to communicate in safe mode.
My rooter detected an active device having IP 192.168.1.1, but the device was not responding not even to ping.

Then I tried a "fresh" one, it was working properly.
I started it in safe mode, LED was blinking fast.
Again the rooter detected it, but still no communication was possible.
Returning to normal mode, everything was fine.


What could be wrong?

P.S.
In my LAN there is a PC that has static IP of 192.168.1.1, but I have disconnected it.
I tried also to communicate through 10.1.0.1, adding an IP to my PC as 10.1.0.100 with sub net mask 255.255.255.0, but still there was not any response!

gr

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Re: Problem in safe mode of SBC65EC
« Reply #1 on: November 20, 2012, 08:44:36 PM »
Hopefully someone more knowledgeable will reply.  I haven't used these boards in a while.

- I recommend you disconnect completely from any network and connect a $20 hub to both the PC and the device.  Set your mask to 0.0.0.0 so that no routers are involved.  Ping and web browser should both be able to talk to the SBC.  Set your ip address manually on your pc (not using DHCP).  Once you get web acces, update the boards ip address to the address that is most convenient when connected to your network.

-A blinking LED is a very good sign.  The board is probably fine.

- Don't touch pin B0 - leave it tristated.  More here:
http://forum.modtronix.com/index.php?topic=1555.msg4828

AlexKots

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Re: Problem in safe mode of SBC65EC
« Reply #2 on: November 21, 2012, 01:06:19 AM »
gr,
Thanks for your reply.

I have already tried a twisted cable connection.
My PC IP is 192.168.1.2 and I have been set the "good" SBC65EC as static IP having 192.168.1.11
So at normal operation every thing is fine.

But when I power up it in safe mode, the device is not responding at 192.168.1.1 as it should be.
It is not responding at 10.1.0.1 also.

The device is not connected to any I/O. All I/O bits are open.

gr

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Re: Problem in safe mode of SBC65EC
« Reply #3 on: November 21, 2012, 07:56:54 AM »
There's free software for the PC called wireshark. 

Install that, start capture and turn on the SBC, then once the LED starts blinking turn off capture.   Try to keep your capture time short as there may be tons of other packets on the LAN unrelated (hence my earlier suggestion of using HUB).

Look at mac address of packets and ip address of packets - there should be some activity from the SBC board when it tries to get an ip address through DHCP.  That might also tell you what IP address the board wants to be at.

In safe mode, sometimes these SBC boards only listen for the first 2 seconds after you turn them on.  Especially if for example you told it to set pin B0 as an output (which kills network ability of SBC).  If you run the modtronix bootloader program, you can time the power cycle and the bootloader exactly (not sure if you turn the board on first and then click connect on bootloader or other way around or if you wait .5 seconds or what).

AlexKots

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Re: Problem in safe mode of SBC65EC
« Reply #4 on: November 22, 2012, 04:33:36 AM »
I have a capture software from Soft Perfect, and I downloaded the Wireshark too.
Both give the same results.

To avoid any other traffic I have connected the SBC directly to PC with a twisted cable.

At normal operation the SBC is working properly.
I have set the IP address to 192.168.1.11
The first time I request anything form SBC, an APR Request is send from my PC, asking who has that IP.
SBC replies with its MAC address (00:50:C2:6A:D7:4D).
And then the PC is sending HTTP or UDP packet (depending on how I chose to communicate, browser or my application).
The SBC replies with an equivalent packet.

At safe mode I request data from 192.168.1.1
Again an APR Request is send from my PC, and SBC replies with its MAC (00:04:A3:00:00:00).
Then the PC is sending http or udp packet, but SBC does not reply any packet.

The only difference I see is at APR Reply "data" ("Padding" is called by the tracking software).
both are 18 bytes, but in normal mode the data are 00 00 00 00 00 80 00 04 00 00 00 00 00 00 00 00 00 00
and in safe mode they are 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
I do not know the meaning of those data.

--

As for the "damaged" SBC, I set it at safe mode and used Netloader, but it was not connected.
I tested the last IP I had given to it (192.168.1.10) and it was connected!
Updating EEPROM everything was OK.

Then I connected normally, I changed IP etc, and after power up SBC was again not responding!
I used Netloader again to restore it (hopefully the IP 192.168.1.10 that I had programmed, was again not damaged).
Then I changed again IP etc, but this time I waited for 10 seconds before remove power.
I do not know if THIS delay was needed, but this time SBC is functioning OK.


So my final conclusion is that when changing values in EEPROM and after submit button, we should wait for few seconds before remove power.
I can't find any other reason why the SBC is been "blocked".


Finally I used a "fresh" one in safe mode, without changing any of the initial setup values.
But my rooter says that an unknown device is connected at 192.168.1.1 having MAC 00:04:A3:00:00:00 (as it should be)
But again no reply was returned using address 192.168.1.1, either pinging, either udp, either http  :x :x :x

So my final question is:

Does anyone knows how we can communicate with SBC65EC in safe mode ?

gr

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Re: Problem in safe mode of SBC65EC
« Reply #5 on: November 22, 2012, 07:04:03 AM »
My understanding from the manual is that safemode is for bootloader purposes only.  In safemode it will respond to 3 different possible ip addresses but once you start communication it sticks with that ip address.

From the bootloader I only know how to reset the ip address back to the default which turns on DHCP (there's a checkbox 'update eeprom configuration data').  I don't know how to set the ip address to anything other than the default which is to use DHCP. 

Don't you have a DHCP server on your network?  If not you can use an old NAT router and setup the NAT router as a DHCP server that gives out a limited range of addresses.

Anyway when I had multiple SBC boards I just hooked them all up one at a time and gave each of them a different NetBIOS name (mxboard1, mxboard2, mxboard3 and so on).  And I labeled the SBC boards with a sharpie pen.

So my recommendation for the rest of the SBC boards is to connect them up one at a time.  Turn them on, go to a dos like CMD prompt and type "ping -a mxboard".  ping will use netbios to tell you what IP address the board is at.  The -a option will let you know the ip address.  Then go to a web browser, go to that ip address and change the netbios name to something unique and optionally set the ip address to a unique value and disable DHCP.