skips to block 470 if it is the routine checks if the door is stopped in the fully open position at block 464 if no the routine skips to block 470 if yes the routine calls the setvarlight subroutine see fig8 to enable the appropriate turn off time 4 5 minutes for 60 hz systems or 2 5 minutes for 50 hz systems at block 468 the routine turns on the worklight at block 470 the microprocessor 300 clears the one shot flag for the infrared beam break this resets the obstacle detector so that a later beam break can generate an interrupt at block 472 if the user has installed a temporary password usable for a fixed period of time the microprocessor 300 updates the non volatile timer for the radio temporary password at block 474 the microprocessor 300 refreshes the ram registers for radio mode from non volatile memory eeprom 302 at block 476 the microprocessor 300 refreshes i o port directions i e whether each of the ports is to be input or output at block 478 the microprocessor 300 updates the status of the radio lockout flag if necessary the radio lockout flag prevents the microprocessor from responding to a signal from a remote transmitter a radio interrupt described below will disable the radio lockout flag and enable the remote transmitter.