switched non conducting by a line 450 connected to its gate a transistor 462 coupled via a resistor 464 to a line 466 is switched on biasing a transistor 468 on causing current to flow through a diagnostic light emitting diode 470 to a field effect transistor 472 which is switched on via a voltage on a line 474 in addition the capacitors 386 384 and 382 which may have been charged are discharged through the field effect transistor 472 in order to perform all of the switching functions after the step 424 has been executed control is transferred to a step 510 testing whether the got switch flag has been cleared if it has control is transferred to a step 512 in which the command timer is incremented and all other timers are decremented and the got switch flag is set and the routine is exited if the got switch flag has not been cleared as detected in the step 510 the routine is exited in the step 514 in the event that the sense input is measured as being high in the step 424 control is transferred to a step 516 where the vacation or lock flag counter is incremented and all other counters are decremented the got switch flag is set and the routine is exited in the event that the switch status equal 10 test in the step 422 is indicated to be no control is then transferred to a step 520 testing whether the switch status is 11 if the switch status is 11 indicating that the routine has been swept through 11 times control.