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RS 232 to a USB connection
http://solar-guppy.com/forum/viewtopic.php?f=15&t=505
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Author:  Solar San Jose [ Mon May 21, 2007 8:51 pm GMT EstGMT ]
Post subject: 

Solar Guppy wrote:
So you plugged the usb's db9 directly into the GT? , that should work ..

Is the GT running and displaying info on the LCD?

When you did 1ft test, was TX light on but still no RX?


Solar Guppy,

Yes, directly into the GT, and yes, I'm pretty sure the TX light was on and RX never lit -- but I'll check again today. And yes, the inverter was displaying info on the LCD.

One thing I just thought of: I'm using a SunPower inverter, not a Xantrex, but I was told they're the same except for the logo. And the software does work with a "normal" RS-232 serial port (and using my 30ft hand-made cables, too, for that matter).

Thanks,

- Matt

Author:  Solar Guppy [ Mon May 21, 2007 9:14 pm GMT EstGMT ]
Post subject: 

One last test, is use a different PC with the USB converter, this will rule out some OS issue with the laptop. If it doesn't work on a second PC then
Time for a new usb-> serial as you have proven everything else is fine.

And yes your spr is just a re-branded GT and works the same with GT-View

Author:  Wennfred [ Tue May 22, 2007 10:28 am GMT EndGMT ]
Post subject: 

Solar San Jose wrote:

I tried checking the BIOS and didn't see anything interesting; I assume you suggested that because you were thinking there might be a BIOS conflict with the COM port?



No, nothing to do with a BIOS conflict, some Motherboards have a feature to Turn on or off the USB, if the motherboard gets glitched, it can go to default settings and you will have to go back into the BIO settings to turn on the use of the USB's.

Read this link: http://www.eicon.es/support/helpweb/spd2en/bios.htm



Fred

Author:  Solar San Jose [ Tue May 22, 2007 11:16 am GMT EndGMT ]
Post subject: 

Solar Guppy wrote:
One last test, is use a different PC with the USB converter, this will rule out some OS issue with the laptop. If it doesn't work on a second PC then
Time for a new usb-> serial as you have proven everything else is fine.

And yes your spr is just a re-branded GT and works the same with GT-View

Solar Guppy,

Hmm, I'm not sure that's going to show anything. I use that USB port all the time with other devices, and I've even used the USB-to-serial cable successfully with a simple loopback (pin 2 connected to pin 3) which should basically be exactly the same setup as talking to the GT itself...

This is actually the second USB-to-serial cable I've tried, but I think now I concluded too quickly the first was defective, when it appears I have some other problem.

I will try a Linux device: that was my long-term plan anyway, because it'll use a lot less power than a full laptop (hope you don't mind that I won't use your excellent software!), but I'm not very hopeful about the outcome...

Wennfred wrote:
No, nothing to do with a BIOS conflict, some Motherboards have a feature to Turn on or off the USB, if the motherboard gets glitched, it can go to default settings and you will have to go back into the BIO settings to turn on the use of the USB's.

Read this link: http://www.eicon.es/support/helpweb/spd2en/bios.htm

Fred,

Thanks for the suggestion. I don't think that's my problem, though.

- Matt

Author:  Solar Guppy [ Tue May 22, 2007 12:59 pm GMT EndGMT ]
Post subject: 

Quote:
Hmm, I'm not sure that's going to show anything. I use that USB port all the time with other devices, and I've even used the USB-to-serial cable successfully with a simple loopback (pin 2 connected to pin 3) which should basically be exactly the same setup as talking to the GT itself...


trying on a second PC would rule out the laptop as the issue and show the converter is the issue or not. Loopback is meaningless if its a voltage level issue with the laptop ( doesn't put out true rs232 levels )

regardless, if GT-View won't work with the usb-converter your linux won't fair any better. And on power usage, linux vs winxp is the same, its the hardware not software that consumes watts.

Author:  Solar San Jose [ Tue May 22, 2007 4:18 pm GMT EndGMT ]
Post subject: 

Solar Guppy wrote:
trying on a second PC would rule out the laptop as the issue and show the converter is the issue or not. Loopback is meaningless if its a voltage level issue with the laptop ( doesn't put out true rs232 levels )

regardless, if GT-View won't work with the usb-converter your linux won't fair any better. And on power usage, linux vs winxp is the same, its the hardware not software that consumes watts.


Solar Guppy,

If it's a voltage-level issue, then trying on a different PC would still have the same problem, wouldn't it? (Unless the USB port weren't powered at all, but other devices don't have problems.)

I'll try an experiment just using a null-modem cable to another host to see if that works, but I'm returning to the idea that maybe it's the RS232 on the *inverter* that's the problem: its voltage levels are good enough for built-in RS232 ports, but not enough for the USB-to-serial cable. OK, seems unlikely, I know, but that's the only theory that fits all the facts.

I plan to use a Linux appliance, not a full-blown PC, with a USB memory stick as its nonvolatile memory. See this link: http://www.nslu2-linux.org/. I've measured power < 5W on mine.

Thanks for all your help!

- Matt

Author:  mike90045 [ Fri Jun 08, 2007 4:23 pm GMT EthGMT ]
Post subject: 

Solar San Jose wrote:

I plan to use a Linux appliance, not a full-blown PC, with a USB memory stick as its nonvolatile memory. See this link: http://www.nslu2-linux.org/. I've measured power < 5W on mine.

Thanks for all your help!

- Matt


This is pretty interesting - The Linksys NSLU2 is a Router, and you reflash it with new firmware ? Can it run data collection apps, like GT View (via WINE)

Author:  Solar San Jose [ Tue Jun 12, 2007 7:09 pm GMT EthGMT ]
Post subject: 

mike90045 wrote:
This is pretty interesting - The Linksys NSLU2 is a Router, and you reflash it with new firmware ? Can it run data collection apps, like GT View (via WINE)


Hmm, I don't think you could get it to work. I'm a Linux newbie, so I don't really know, but the memory restriction is pretty severe, and Wine would have to be ported to this platform, which is headless, so... no, I don't think that's an option.

Also, an update: Solar Guppy was right! My USB-to-serial cable *was* bad (could transmit but not receive), and now with a new one I can use GT-View just fine. (By the way, you can get *very* cheap USB cables on ebay!)

Author:  mike90045 [ Tue Jun 12, 2007 9:10 pm GMT EthGMT ]
Post subject: 

Solar San Jose wrote:
Hmm, I don't think you could get it to work. I'm a Linux newbie, so I don't really know, but the memory restriction is pretty severe, and Wine would have to be ported to this platform, which is headless, so... no, I don't think that's an option.


Uh, then what does the memory stick and the router do ? Do you have another box running GTview and doing what with memory & router ??

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