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Re: [TowerTalk] M2 2800 rotator questions

To: "" <>
Subject: Re: [TowerTalk] M2 2800 rotator questions
From: Rick Tavan N6XI <>
Reply-to: Rick Tavan N6XI <>
Date: Wed, 3 Aug 2005 18:07:04 -0700
List-post: <>
On 8/3/05, <> wrote:
> I have two questions about the M2 2800 rotator and hope this is appropriate
> place to ask.  First, I am interested in computer control.  I have no RS-232
> ports left on my computer but I do have USB ports.  Will a USB to Serial
> converter work ok for that application?

It works for me on an IBM T42 running XP Pro and Writelog.

>  If so, the program (logging program
> XMLog) asks for the port number for rotator control. Does a USB port get
> assigned a port number (like comm1, comm2, etc.)?

Yes. You can often coerce the automatically assigned COM number to
something else using Device Manager if your logger insists on a
limited set of numbers.

>  I know my comm1 is a
> RS232 and likewise my second RS232 is comm2 but my USB ports don't seem to
> have a number?

Device Manager should show some limited information on serial ports
associated with USB adapters. Select Control Panel | System | Hardware
| Device Manager and look for Ports and Universal Serial Bus
Controllers. The info is less than transparent. You can double click
on a serial port to change many of its properties including, in some
cases, the COM port number.
> Lastly, The ads for the m2 states there is "10 presets and 1 flexible
> pre-set" but I can't find anything in the manual about a 'flexible preset?'

Dunno what that is. In Mode 0 (1?) it turns while you hold buttons. In
Mode 1 (0?) it changes the display while you hold buttons and then
turns to the selected heading after you let go for a few seconds. This
may be what they are calling a "flexible preset." Computer control
puts it in this mode. In Mode 2 it steps through the presets when you
push or hold buttons and then turns to the selected preset heading
after you let go for a few seconds. The Mode is the left-most digit.
The next digit to the right is the preset number, 0-9.

Welcome to the wild and wacky world of the M2 2800 digital controller.
For your sanity, I advise against reading the so-called instruction
manual, at least the one they were shipping three years ago when I
bought mine. It is more of a Confusion Manual. In fact, it is the
absolute worst documentation I have ever seen for any piece of
equipment, worse than the worst Jinglish I've ever had to deal with.
And I think it was written by a pleasant, clever engineer whose native
speaking language is English!

The hardest task is recalibration, something you have to do
occasionally. It is impossible to do it by following instructions in
the manual. I had to talk to them on the phone for about 20 minutes to
figure it out. That was three years ago. By now they must have learned
how to explain it more quickly because everyone has to get help. Who
knows, maybe they even hired a tech writer to compose a coherent
explanation. But if not, here's what you do: First you turn the
antenna to a known heading such as 0, ignoring the readout. There is a
function mode in which the direction display changes but the rotor
doesn't turn. I am in the wrong town right now so I can't dig out the
doc and tell you what that mode is called there or how to get to it,
but it's less than obvious. You use that to reset the readout to the
now-known heading of the beam. Then you invoke a magic incantation
that is mentioned obscurely in the manual to save your work.

Working with that controller and its so-called documentation is
frustrating beyond belief. But when you get it all set up, the thrill
of typing a call into a logging program, pushing a button and seeing
the control and antenna move to the same, correct heading is sublime.
And the motor is a smooth, powerful brute. Have fun and good luck.


Rick N6XI

See:  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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