On 2007-01-02, Grant Edwards <grante@visi.com> wrote:
> On 2007-01-02, Colin MacDougall <> wrote:
>
>> I know a couple of UDS1100's can be placed back to back and
>> tunnelling used to create a transparent RS485/422/232 link
>> between them but does anyone know if it's possible to arrange,
>> say five, units to form part of a multidrop network for remote
>> nodes on the network. I suspect that I'm only going to be able
>> to arrange a point to point connection between two device
>> servers at a time, but wondered if anyone has been able to
>> broadcast data sent from one unit to a group of other units
>> simultaneously?
>
> I don't know about he Lantronix units, but I do know that
> Comtrol's device servers can be configured that way: you can
> configure a DeviceMaster RTS unit to send data received on a
> port to a list of other ports/units.  [Disclaimer: I work for
> Comtrol]

I forgot the link:

  http://www.comtrol.com/products/hardware/dmrts.asp

If you want to do something particularly specialized, there's a
software development kit that allows you to write a custom
application to run on the device-server.
  
-- 
Grant Edwards                   grante             Yow!  HUMAN REPLICAS are
                                  at               inserted into VATS of
                               visi.com            NUTRITIONAL YEAST...

On 2007-01-02, CBFalconer <cbfalconer@yahoo.com> wrote:
> Colin MacDougall wrote:
>> 
> ... snip ...
>> 
>> I know a couple of UDS1100's can be placed back to back and
>> tunnelling used to create a transparent RS485/422/232 link
>> between them but does anyone know if it's possible to arrange,
>> say five, units to form part of a multidrop network for remote
>> nodes on the network. I suspect that I'm only going to be able
>> to arrange a point to point connection between two device
>> servers at a time, but wondered if anyone has been able to
>> broadcast data sent from one unit to a group of other units
>> simultaneously?
>
> Tunnelling?

Across the Ethernet connection between the device-server units.

> Yes, but you have to control who is the master somehow.  Time
> slots after an addressed 'permision to transmit' will do.

Due to the nature of delays on the Ethernet TCP/IP or UDP
link(s), the timeslots would probably have to be pretty course.
I think that any Peer-to-peer protocol is going to be pretty
tricky.  A single-master command/resposne protocol should work
easily enough.

> RS485 is a hardware scheme.  The protocol is up to you.

-- 
Grant Edwards                   grante             Yow!  I represent a
                                  at               sardine!!
                               visi.com            

On 2007-01-02, Colin MacDougall <> wrote:

> I know a couple of UDS1100's can be placed back to back and tunnelling
> used to create a transparent RS485/422/232 link between them but does
> anyone know if it's possible to arrange, say five, units to form part of a
> multidrop network for remote nodes on the network. I suspect that I'm
> only going to be able to arrange a point to point connection between two
> device servers at a time, but wondered if anyone has been able to broadcast
> data sent from one unit to a group of other units simultaneously?

I don't know about he Lantronix units, but I do know that
Comtrol's device servers can be configured that way: you can
configure a DeviceMaster RTS unit to send data received on a
port to a list of other ports/units.  [Disclaimer: I work for
Comtrol]

I presume you're using a single-master, multiple-slave protocol
on the RS-485 portions of the network?

-- 
Grant Edwards                   grante             Yow!  Let's send the
                                  at               Russians defective
                               visi.com            lifestyle accessories!

Colin MacDougall wrote:
> 
... snip ...
> 
> I know a couple of UDS1100's can be placed back to back and
> tunnelling used to create a transparent RS485/422/232 link between
> them but does anyone know if it's possible to arrange, say five,
> units to form part of a multidrop network for remote nodes on the
> network. I suspect that I'm only going to be able to arrange a
> point to point connection between two device servers at a time,
> but wondered if anyone has been able to broadcast data sent from
> one unit to a group of other units simultaneously?

Tunnelling?

Yes, but you have to control who is the master somehow.  Time slots
after an addressed 'permision to transmit' will do.

RS485 is a hardware scheme.  The protocol is up to you.

-- 
Chuck F (cbfalconer at maineline dot net)
   Available for consulting/temporary embedded and systems.
   <http://cbfalconer.home.att.net>

Hi,

I've got an application that requires a number of environmental controllers
be connected on an RS485 2 wire half duplex multidrop bus. I was looking
at the Lantronix UDS1100 device servers (or even the older UDS100 / UDS10 )
to let me use the customers LAN so as to save wiring costs.

I know a couple of UDS1100's can be placed back to back and tunnelling
used to create a transparent RS485/422/232 link between them but does
anyone know if it's possible to arrange, say five, units to form part of a
multidrop network for remote nodes on the network. I suspect that I'm
only going to be able to arrange a point to point connection between two
device servers at a time, but wondered if anyone has been able to broadcast
data sent from one unit to a group of other units simultaneously?

thanks,

Colin