Since the smog check station did perform the EVAP test on your Dolphin 2700 RV we have to assume the EVAP lines were accessible.
Since your Dolphin RV failed the EVAP portion of the smog check you will need to repair the EVAP fault before being able to pass the smog test.
Trace the EVAP lines from the fuel tank to the charcoal canister and check for possible disconnected, brittle, cracked EVAP hose(s).
posted by SmogTips Support