Re: Re: RS485 - XPL on the wire

["Frank Mc Alinden" <fmcalind@xxxxxxxxxxxxxx>]

Hi  Lehane

> I think there is always a case of chicken and egg!

Im probably being a little bit negative in my thinking.......

If running power with comms and using cat5 (rj45 sockets) then i think you
would be limited to 200  to 300mA i would imagine ????


> Connector RJ-45 (two per module)

Comms in / out ???

> There is some info on a PIC based 232<->485 buffered converter
> around and PCI cards can be had at a price. There is also the one
> chip MAX 3162, although not generally available (the MAX3160 is and
> would do the job with another 232 chip).

Not familiar with these Maxim chips.....If a cheap device can be bought
like
the easysync then  thats what i would prefer......

> Pin connections as Modtronix (why re-invent....)

Got a link to the pin outs

> Each module to have option of terminating resistor

Yep good idea

> I'd certainly like to push on putting the LRC into the standard for
> RS232/485 comms whilst things are at an early stage.

As you say its not that hard to implement.........

Have you developed any rs485 hardware ??

Frank



----- Original Message -----
From: "g8kmh" <lehane@xxxxxxx>
To: <ukha_xpl@xxxxxxx>
Sent: Friday, October 22, 2004 7:39 PM
Subject: [ukha_xpl] Re: RS485 - XPL on the wire


>
>
> Frank,
> I think there is always a case of chicken and egg! The more
> information, working devices and demos available, the more it catches
> on. And standards, real or de facto. For example, are we going to put
> power on the 485 cable (presumably yes), 3.3V, 5V, 12V, 24V? Max
> current overall? Per module? Line speed? Cable/Pin connections? If we
> don't get these (and more) specced up front then we won't end up with
> plug and play(!). FWIW, here's my suggestion:
>
> +12V power (min 10V, max 15V - measured at the module)
> 100mA per module max (or module is self powered)
> 2A max per loop current limited with foldback.
> 32 modules max per loop (485 std)
> 19,200 bps (8bits,1 stop,Odd parity)Half Duplex
> Connector RJ-45 (two per module)
> Pin connections as Modtronix (why re-invent....)
> Each module to have option of terminating resistor
>
> There is some info on a PIC based 232<->485 buffered converter
> around and PCI cards can be had at a price. There is also the one
> chip MAX 3162, although not generally available (the MAX3160 is and
> would do the job with another 232 chip).
>
> I'd certainly like to push on putting the LRC into the standard for
> RS232/485 comms whilst things are at an early stage.
>
> Lehane
>
> <snip>
>
>
>
>
>
>
> xPL Links: http://www.xplproject.org.uk http://www.xplhal.com
http://www.xpl.myby.co.uk
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