So, you have some equipment for monitoring temparature sensors and 
logging their readings. And you supply some software that downloads this 
data and lets you organise and examine it on a desktop PC.

Your hardware and software are designed to talk to each other via a 
serial cable connecting the hardware to the PC running the software.

Ah, but some people want to actually, you know, have the PC in a 
different room to where the hardware is. And they'd like to not have to 
dedicate one entire PC to each logger. The answer is simple: your 
product needs to communicate over the network!

Now, you *could* redesign your hardware so it has an Ethernet port, and 
redesign your software so it understands TCP/IP. But you're not going to.

Instead, what you do is supply your customers with a little black box. 
This little black box has a serial connector at one end, and an Ethernet 
connection at the other, and it *tunnels* serial traffic over IP.

You also supply your customers with a blob of software which, when 
installed on a PC, somehow tricks the PC into thinking it has a new 
serial port. All data sent to this port is *actually* tunnelled to the 
little black box.

So, between the little black box at one end, and the custom software 
driver at the other end, the hardware and software geniunely believe 
they're still locally connected, yet actually they can be on different 
continents.

Is this a valid solution to a design problem? Or is it a cheap hack?

[Did I mention that the "software" in question appears to be designed to 
work with Windows 3.0? Does that change the answer?]

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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