Re: RS232 Problems

From: Chris Tacke, eMVP (ctacke[at]Open_NET_CF[dot]org)
Date: 02/18/04 

Date: Wed, 18 Feb 2004 07:35:15 -0500

A logic analyzer or a scope would help you determine if it a handshaking
issue (which it sounds like). Does the device expect power on DSR or RTS
(like a mouse)? You might check to see if the state of these is different
between the PC and the PPC.

-Chris

"Mike" <javaboyjunior@hotmail.com> wrote in message
news:8e18e0ea.0402172235.9b0a154@posting.google.com...
> Hi,
>
> I'm having some issues with an RS232 device I'm using and have seen
> some helpful advice on this group with regard RS232 so am hoping
> someone might have some suggestions.
>
> I have an RS232 device that I need to connect to. It's a custom device
> we had programmed - without going into too much detail, we pass it
> characters, it goes and does things and reports back to us with
> characters. When attached to a PC via a 9 pin serial cable, everything
> works as expected - I get the responses I expect to the characters I
> send. This works as expected with both C++ and C# sample apps.
>
> So then I re-create my samples and run them on a CE.NET device (X86
> platform) and nothing - I cannot get the external device and the CE
> device to talk to each other. I know the serial port on the CE.NET
> device is working as I can connect it up to a PC and transmit
> characters between the PC and the CE.NET device using Hyperterminal on
> the PC and a simple C# app on the CE.NET device.
>
> So I can't figure out if the problem lies with my RS232 device that
> I'm trying to communicate with (works with a PC but not with a webpad)
> or my webpad (works talking to a PC but not to my RS232 device). I
> tried setting the DTR flag on the webpad software as I understand from
> previous postings that this might help but it didn't.
>
> I have to admit that I'm stumped - I'm going to go get one of those
> devices you can put inline on the RS232 line and see if I can figure
> out what's different between the PC talking to the device and the
> webpad talking to the device.
>
> Does anyone have any suggestions as to any config changes I can make
> or anything extra I can test to help me figure out the problem
>
> Many thanks
>
> Mike