> >How critical is the 32-nodes-per-bus limit?
>
> Well how critical is your insurance?
> If you sell it and say it works, and it doesn't, you may be liable.
> If the component data sheet says it is designed to meet the RS485 spec
> which describes up to 32 nodes, and you exceed this, YOU have
> exceeded the component parameters which is YOUR fault.

If you are going to point fingers with capital letters, you should remember
that the spec defines Unit Loads. Not nodes. A typical CMOS trans/receiver
is 0.1 Unit Load. However, the cable, data speed termination and other bits
and pieces hanging off the bus also fall into the equation.
So you could have 128 nodes and meet the spec and/or you could have two and
exceed it.

As a designer, you're at the mercy of the end user anyway. They may buy a
1000m reel for a 100m run and not want to cut the cable (for future
expansion) and coil up the extra in the space under the MIG welder.

Steve.