> > > You can just load the line for say 1mS and measure the current to >know if the 48V is present. Did this with two optocouplers and a zener. Yes, but did you pass part 68 with it? We sample for 1mS with 10 meg, and did pass part 68. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body