Update: 0 - 10VDC to 4 - 20 mA conversion

First off, let me thank all who have responded to my
query. Thankfully was not far off on how one would
accomplish this, but when dealing with an expensive VFD
it was reassuring to ask the list.... wouldn't want to
blow anything up! ;-)

I made a discovery last night. I was looking at the
manual for the drive again and low and behold, there it
was! 0-10VDC input! Basically the confusion had to do
with a terminal missing on the sub-30 HP (gawk) drives.
That pin took an ISOLATED 0-10VDC input. I didn't
notice that there was another pin (which is on my VFD)
that takes a common 0-10VDC input. So, thankfully, my
problem has been solved without even picking up a
soldering iron!

Unfortunately my direction problem won't be quite as
simple. The control has a "spindle on" relay and then a
separate "reverse" relay.... I'll have to change that to
two distinct contact... FWD and REVERSE. With luck I'll
have some spare contacts with which to accomplish this.
If not I'll twiddle a little. But that is all fairly
easy.

Thanks again to everyone who helped. I suspect that
others may benefit from the voltage to current
conversion if they look in the archive.

Alan