Yes you can setup up DHCP per VLAN. The best way is to make sure you have a Network Sensor for each VLAN you want DHCP on. Then login to the UI and in the Top Panel, click on System. Next in the left panel of that screen under System Management,scroll down and select System Defaults and then Network Sensor. In the main window you can scroll down to the DHCP section and populate your various options. Make sure to click update at the bottom of the page in order for your changes to be applied.
Let me know if you have any other questions or concerns.
Bill Eaton firstname.lastname@example.org