Question

Draw a state diagram of the AC/Heater controller described below It has a switch to turn it on or off; A user can select either program P1 or program P2 and can switch from one to another; P1(68F for heat and 78F for cool) and P2( 66F for heat and 76F for cool); There is a sensor for measuring the room temperature; If the controller is set to program P1 and the room temperature <68, then the heater is turned on, and stays on until the temperature reaches 68; If the controller is set to program P1 and the room temperature >78, then the AC is turned on, and stays on until the temperature reaches 78; If the controller is set to program P1 and the room temperature is between 68 and 78( including 68 and 78), then both heater and AC are off; Similar rules are applied for program P2.

Answer 1

Initial S POWER OFF POWER a ON RESET S| START PROGRAM PROGRAM = P1 P 2 AC = O F E AC =OFF S2 HEATER= OPF HE ATER = OFF T66E TET&F T:76F Te 68F T>76F T 68F T718F S5 AC ON HEATER ON

S0,S1,S2,S3,S4 and S5 are states.

S0= Power OFF / INITIAL STAGE
S1=Power ON / RESET Condition
S2= AC OFF and HEATER OFF
S3= AC OFF and HEATER OFF
S4= HEATER ON
S5= AC ON

INPUTS

POWER
T=TEMPERATURE
RESET