What was found
DURING A GRADUAL DESCENT OUT OF CRUISE THE CREW LOST CONTROL OF CABIN PRESSURIZATION. THE CABIN ALTITUDE CLIMBED TO 10,000 FT AT 9500 TO 1200 FPM. CREW INITIATED AN EMERGENCY DESCENT TO ATTEMPT REGAINING CONTROL OF CABIN PRESSURE AND PREVENT FURTHER CLIMB. COM PROCEDURES WERE COMPLIED WITH AND PROBLEM WAS CORRECTED BY GOING TO MANUAL CONTROL AND THEN BACK TO AUTOMATIC CONTROL. LANDING AT MSP WAS WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED BOTH DIGITAL CABIN PRESSURE CONTROLLERS AND RETURNED THE AIRCRAFT TO SERVICE.