As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHORTLY AFTER TAKEOFF WE RECEIVED IAS COMPARATOR AND ALT COMPARATOR FLAGS FOLLOWED BY EFIS COMP MON, MACH TRIM, AND STALL FAIL CAUTION MSG. DECLARED EMERGENCY. RETURNED TO FIELD. (FLT#3600) FO: 03/04/2019 CLOSED REMOVED AND REPLACED NR 2 ADC COMPUTER IAW AMM. OPERATION AND FUNCTIONAL CHECK GOOD OF ADC AND MAIN PITOT STATIC SYSTEM. NO FAULTS NOTED.