[Elecraft] KAT500 help

[Wes]

Somehow I misplaced the data cable used to configure the KAT500. As I recall I 
had the USB version but since I have more RS232 ports than USB ports available 
these days I ordered what I thought would be a replacement. 
https://www.amazon.com/gp/product/B06Y98F6D5/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Unfortunately, it doesn't work; the KAT fails to find the port. I've used two 
different computers and the ports that run other devices just fine, so I know 
they are operational.  I've traced the pins to the tip and ring of the cable and 
they are correct.

Has anyone ever used real RS232 signal levels into one of these, or does it 
actually only work with USB?

Wes  N7WS