I've been using a ISA/DRTS-3 more than 4 years. although it's not as powerful as Omicron, it's a cheaper option. Also you can easily prepare your own set algorithms.
Else, you can purchase Freja, from Programma Inc. Both Omicron and DRTS are fully contolled with a PC (you can never work this...
you can also use
. ETAP, by OTI - www.etap.com
. NEPLAN - www.neplan.ch
. LAKU and NetDraw (use google for it) there are commercial and non-commercial versions.
with using the "search" option in eng-tips, you can find some previous threads on this matter.
regards,