Lost/Duplicate Messages - working with no Hub.

["barrygordon" <barry@xxxxxxxxxxxxxxx>]

First of all my apologies to Patrick Lidstone for getting his name
wrong.

Second, all of what I thought would be threads on the original
message appear to be seperate posts so I will try to answer them all
in this posting.

All problems are now resolved.  The lost/duplicate message problem
was definately some sort of a pacing problem at the receiver. I
understand the issues with UDP re sequencing and guaranteed
delivery.  I have been doing computer and networking work since 1960,
with many interesting experiences and stories regarding what it was
like before there were languages, Ethernet, you name it.  I was part
of the team that developed the original GPS solution/system for the
US military.

On my local in house network, the error rate is infinately small.
Before I put in pacing logic (Ack every block of a large message) I
generally would get N copies of the last block of a multi block
message,  Now I get each block and in perfect sequence.  I believe I
have it properly handling Multiple units transmitting at the same
time, since the multiblock issue can only occur in one direction,
Homeseer to touchscreens.  The touchscreen to homeseer messages are
classically very short, e.g. 20-80 bytes of data.

On the HUB problem; upon re-reading the spec I figured it out.  It
seems that to force the issue properly on the xapax.ocx activeX
control the port, minport, and maxport items need to be set to 3639
and it works like a champ.  I thought that the xapax.ocx activeX
control handled that, but perhaps I have a "old" version.

I guess in my app I could try opening 3639 and if it can't then there
is a hub and if it can there is.  I just thought that the control did
that.  Perhaps I am still doing something wrong.  I have no
documentation on the control and would appreciate having some.
Patrick?  (I can be reached at barry@xxxxxxx)

Now to answer some questions:

All of my coding is in VB6.  I am just comfortable in that domain and
too old to change.  I have looked at .net, but once again that is
change. C++ or C# well, same story.

The touchscreens are actually Panasonic CF01 hand held computers that
cost $3000 when they first came out. When I bought them about 2 years
ago I paid $350 apiece, new in the box with the docking station. They
were originally used in inventory and wharehouse work. They are about
8x5x1.5 inches in size, 1.5 Gig HD, 24 meg main memory, expandable to
40 Meg. Most of my units are at 24 meg. The screen is a full
touchscreen measuring about 7x4. Good briliance and runs at 800x600.
It will run Win 95 or 98, but with 98 you lose control of turning on
and off the backlight (Screen blanking).  A friend designed an in
wall enclosure and that is how my units are set up.  They have two
PCMCIA slots, and a docking station that has lots of connectivity.
Battery lasts about 2 hours.  I have 2 spares, one for parts and one
for testing.  I have not seen any adds for them anymore.

I modded the units so I can power them on and off via an X10
interface module, so they will always be restarted when they stop
sending the "alive" heartbeat. The Main computer,
"Homeseer", is on a
UPS and half the house (the half with homeseer) is on a fully
automatic standby generator. Homeseer just does not stop (If I leave
it alone!)

If you want to see what they look like go to my web site www.the-
gordons.net and browse around following the home automation links.

Thanks to all for all of the replies and suggestions.  This is an
excellent working group.  Hope I can contribute