Spyder BACnet Programmable Controller, Unitary Applications, 24 Vac with a Valid Range of 20-30 Vac, -40-150 Degree Operating Temperature Range, I/O Count: 4 UI, 0 DI, 2 AO, 4 DO, Output Type: Pulse with Modulation, Floating, Staged On/Off, Compatible with WEBs-AX and WEBs-N4 Interfaces, BACnet MS/TP Network Communications