I use apcupsd, works well with different APC models including SmartUPS 700
Make sure you specify cable part number in the config file according the number marked on the side of connector 940-00(20B,23A,24B,24C,24G,95A,95B,95C),
940-15(24C) etc.
Use how-to from myezserver.com (Thanks Darell).
Read apcupsd manual for detailed description of different types of signaling cables.
Good luck.