flag ton should be 34 no 34 and it may be assumed that the reset flag status is also 34 no 34 so the flow will be around a loop of the three decision blocks 110 112 and 114 the temperature t will normally drop until its value is less than ton when the flag ton will set to cause the program to go to a calculation block 116 at block 116 the clock dwell begin time value cdb is set equal to the clock time value c the flow goes to a decision block 118 where a status check of flag toff will be 34 no 34 status checks at blocks 120 and 122 for reset flag r and clock normal offset status flag cno will both be 34 no 34 so that the program goes around a loop of blocks 118 120 and 122 the furnace is now running to supply heat so that the temperature t will rise until it is greater than toff at which time the flag toff will set so that at block 118 the program branches to a calculation block 124 at block 124 the clock dwell end time value cde is set equal to the clock time value c the next blocks 126 and 127 are for calculation of clock dwell correction factors and the clock normal offset time required to achieve the normal temperature at the time cn equ1 after performing the calculations at block 127 the program returns to the decision block 110 and as long as the clock has.