[GreenKeys] Black Box RS-232 - current loop converters available

[gfmurphy at earthlink.net]

Greenkeyers:  There are 2 Black Box RS-232 -- current loop converters
available on that popular internet auction website.  Look for item no.
180604929692.  The auction includes 2 new converters, one wall-wart 
power supply and the instruction manual.  The instruction manual is
also available at:

   http://www.blackbox.co.uk/documents/manuals/C/CL050.pdf

These units cannot handle high-voltage loops.  However, a small outboard
circuit (opto-coupler and a HV keying transistor) can be added to make
it work with HV loops.  

Holiday greetings to all.

Jerry Murphy