Subject: B&B's Data Communication Newsletter - May '04 

Let’s help get your data from point A to B. Todays 
issue will answer some recent questions I’ve received. 

   Got this from Andrew: 

Your cool little serial servers are just great, but they 
sure do add up. EG, try to connect 100 serial-port-equipped 
digital scales to a PC to log their data where they are each 
more than 90 meters apart covering a property of about 200 acres. 
The scales are EUR100 apiece. The network to connect them all is 
significantly more. 

   Any help on how to do this cheaply would be fabulous. 

A: Hey Andrew, odds are good that those scales aren’t pumping 
out that much data. That and the distance you need to cover 
makes a great case for taking advantage of the RS-485 
multidrop capability built-in to the Vlinx Ethernet to serial servers. 
You’ll need an RS-232 to RS-485 converter on each of 
the scales if they don’t already support RS-485. Up to 32 
scales could easily share a single port on the Ethernet to 
serial server. 

For info on 232 to 485 converters: There's a broad selection at 
http://www.bb-europe.com/rs485chart.asp?s=ee050404

   Got this from Stephen: 

Q:  Problem is, most of the PCI cards I see come from some
untouchable corner of the globe. Would be nice to KNOW (1) 
what's going on in the PC and communications side so I could 
spec a more readily available domestic replacement when these 
cards decide to self-destruct (takes about 4-5 years, but it 
happens) and (2) what's available. PS - Love the newsletter. 

A: Stephen, the old "Goodbye RS232" trend is driven hard by 
the computer manufacturers -- serial ports get replaced by USB 
and Firewire; ISA becomes PCI.  So for serial we've got 
a line of cards with serial ports, and yes, we still sell 
ISA cards too.  When we make something, we keep producing 
it for a long, long time. 

As for replacing the card when it fails, that's 
a caveat emptor situation.  I can only promise you that if 
WE sell it, we'll support it. 

   From Alan: 

Q: This is for a Toll Road... 253 km of Ethernet, carried by 
anything from DS1 to OC3. We want to install 175 sites with 
some sort of WIRELESS, but 802.11 isn't good enough. Maybe 
mesh networking 802.11, but it too expensive yet. 

I need something that works in some noise.  We have people 
who think an Ethernet cable can't be longer than 6 meters
Yes, we have bought your stuff before... but it never breaks, 
so we haven't bought more...

A: I'm gonna guess that for highway roadsigns and such, 
you don't need 55 Megabit Ethernet, is that reasonable? 
Given that, wireless 485 is a pretty good bet.  An industrial 
grade radio modem can transmit serial or Ethernet data.  
Here's a good option: 

You can convert and transmit data, with no site license and no 
cables, and do peer-to-peer, multipoint and multidrop networking: 
http://www.bb-europe.com/dept.asp?dept_id=98&s=ee050404

Antennas can extend the distance over 20 km, give us a ring 
or drop an email to mailto:support@bb-europe.com?subject=Antennas 
to discuss your application.

Also don't forget that fiber is great for both distance AND 
noise.  We've had a lot of highway & transportation customers 
use Ethernet over fiber: 
http://www.bb-europe.com/dept.asp?dept_id=11&s=ee050404


Rants?  Raves?  Rude asides or data communication questions 
of your own?  Always happy to hear from ya. 
mailto:support@bb-europe.com?subject=E-connections 

Happy Connections. 

Mike Fahrion 
B&B Electronics 

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