Re: [Bacnet-developers] Win32 Port - Timing problems?

[Steve K. <st...@ka...>]

Hi Clayton,

Thank you for looking into running MS/TP on Win32.  It will be nice if
you can solve the issues to get it working as best it can.

> I'm sure that Steve will jump in soon

Thank for the urging, Jason! I was just watching to see how this
problem could be approached from another perspective.

> MS/TP has very intense timing requirements.  As a result, nobody has
> yet been successful in implementing it on Windows or Linux.

As far as nobody - that is probably true of this stack - but other
vendors (JCI, Polarsoft) have Win32 drivers that make MS/TP work
(thanks for the info, Sam!). I have used Polarsoft BACbeat with this
driver, and some USB-RS485 converters work well, and some don't work
so well.

However, Chipkin Automation has a user mode application that runs
MS/TP (CAS Explorer).  Stephen discussed his application with me at
the last BACnet plugfest and shared the open source serial library
that he uses in his code.  He mentioned that he had hand optimized his
MS/TP state machine code and datalink layer, and was using the
processor clock (rather than mulitmedia timer) to get better timings.
I mentioned these and the serial source link in a previous post to
this mailing list[1].

I think that changing this stack Win32 serial code to use the overlap
mode and the packet send would indeed help, fixing the dlmstp.c for
Win32 optimization, and any other of my "bad" win32 coding practices
(threading) that I have done can be fixed to give at least a "lenient"
timings interface on Windows.

I do most of my PC to MS/TP work using a BACnet router, as Jason has mentioned.

Best Regards,

Steve
[1] https://sourceforge.net/mailarchive/forum.php?thread_name=f4a368e50f215c6b0771875f199ce6f9%40localhost&forum_name=bacnet-developers
-- 
http://steve.kargs.net/