Thanks for Your replies and suggestions on this topic. I now know at least two things I didn't before. 1. My problems hasn't got to do with using CommX from Greenleaf, I would most likely get the same problem with other software drivers. I have asked Greenleaf about this several times, but has not yet got a meaningful reply. 2. I now understand why a lot of RS485 devices with master/slave protocol uses full duplex. ============================== Ruben Jvnsson AB Liros Elektronik Box 9124, 200 39 Malmv, Sweden TEL INT +46 40142078 FAX INT +46 40947388 ruben@pp.sbbs.se ============================== -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu