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From: mpm on 24 Jul 2010 20:17
On Jul 24, 6:12 pm, Rich Webb <bbew...(a)mapson.nozirev.ten> wrote:
> On Sat, 24 Jul 2010 15:25:52 -0700 (PDT), mpm <mpmill...(a)aol.com> wrote:
> >Thanks Rich, this looks perfect.
> >Have you worked with these modules before?
>
> I played with them (er ah "evaluated suitability for an application") a
> couple of years ago.
>
> >Do you (or anyone here) know if you can issue a broadcast message and
> >have all units in range respond, or MUST you know in advance the
> >address of each module prior to starting a session with it??
>
> I *think* that each module "discovers" others in range and can be
> queried for the IDs of accessible modules. I'll have to dig out the kit
> (if it's here and not at the office) and play^H^H^H^H evaluate them some
> more to refresh my memory, though.
>
> --
> Rich Webb     Norfolk, VA

Thanks !!!
I would really appreciate it!
From: Rich Webb on 25 Jul 2010 09:29
On Sat, 24 Jul 2010 17:17:17 -0700 (PDT), mpm <mpmillard(a)aol.com> wrote:

>On Jul 24, 6:12�pm, Rich Webb <bbew...(a)mapson.nozirev.ten> wrote:
>> On Sat, 24 Jul 2010 15:25:52 -0700 (PDT), mpm <mpmill...(a)aol.com> wrote:
>> >Thanks Rich, this looks perfect.
>> >Have you worked with these modules before?
>>
>> I played with them (er ah "evaluated suitability for an application") a
>> couple of years ago.
>>
>> >Do you (or anyone here) know if you can issue a broadcast message and
>> >have all units in range respond, or MUST you know in advance the
>> >address of each module prior to starting a session with it??
>>
>> I *think* that each module "discovers" others in range and can be
>> queried for the IDs of accessible modules. I'll have to dig out the kit
>> (if it's here and not at the office) and play^H^H^H^H evaluate them some
>> more to refresh my memory, though.
>
>Thanks !!!
>I would really appreciate it!

Short answer: yes. Longer version: Set the modules to a selected channel
(one of 15 for XBee and one of 12 for XBee Pro) and PAN (personal area
network) ID (one of 65536). Have the base station periodically send a
"who's there?" message and/or have individual nodes send an "I'm here"
message to the broadcast address. The application firmware would sort
out the replies and go on from there.

Modules have a factory-set 64-bit address or can optionally use an
end-user selected 16-bit address. One address (0x000000000000FFFF) is
reserved as the broadcast address in both the 64- and 16-bit address
spaces.

Messages to broadcast addresses are not automatically ack'd by the
firmware. Point-to-point traffic (i.e., to a specific address) requires
an ack at the transport layer and will retry several times, if needed,
transparent to the application layer.

This is from the manual and modules with V 1.06 firmware from back in
2005/6 but I wouldn't expect newer releases to be less capable.

--
Rich Webb Norfolk, VA
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