Here is the manual for the Sorensen XT S20 bench power supply:
http://www.ptbsales.com/manuals/sorensen/xt.pdf
Unfortunately it does not seem to have information on programming with the J-305 analog interface:
UPDATE:
Here is the j-305 pinout:
http://www.helmar.com.pl/helmar/biblioteka/pdf/hpd_data_sheet.pdf
So far I’ve tried to get the TTL shutdown to work, unsuccessfully.
Prometheus Fusion Perfection 
This looks like the prog interface,
Click to access XT_Series_APG_User_Guide_5A6H-01XN.pdf
Might be something useful in here:
http://www.sorensen.com/products/HPD/downloads/