【正文】 nce unconditionally, once present the system halted during a job, can certainly resume when restored to the throne next time. As to only instrument that show, some reading mistake that 1s appear accidentally there is no memory to the next measurement, be could bear , belong to “pass” mistake. This kind is restored to the throne the advantage of dog39。s circuit for guarding the gate regularly, first, change waiting time into a dormancy state, time to shorten and may be interfered。 Second, avoided happenning that the dog controls the death circulation of the link to include guarding the gate. The external condition is restored to the throne the law Some arrival that export or measure is controlled by the outside. For instance, the hot form. of heating, rotate the pulse produced and calculate heat by hot water water wheels, there is no hot water to flow, there is no heat to export, CPU only need in fact keep number value, do not need to count. Can imagine hot water water wheels rotate when parking warm , CPU idle in will it be will it be one season autumn spring and summer, If let dormancy its , measure have water wheels pulse constantly, antiinterference ability can strengthen greatly. So, so long as link up the restoring to the throne of the pulse of the water wheels and CPU, the water wheels rotate a circle each time, CPU is restored to the throne once, hot form. can work normally , this is restored to the throne the law by the external condition . Similar application have half electron kilowatthour meter , go on one count just when the machinery degree wheels and transfers to a circle, users do not need the electricity, CPU has been knowing the dormancy all the time . The restoring to the throne in the interval not to be regular, but confirmed according to the external condition of this method. In some occasions, the time of the dormancy will be very long, very effective to improving antiinterference ability. 2 .The hardware realizes the main point Restored to the throne regularly unconditionally Generally have 2 kinds of methods. ① Use theitimer or the specialpurpose clock chip to be restored to the throne. Fig1, in order to use the timing circuit that 555 circuit makes up。 Can use the clock chips of X1126 ,etc too , wake CPU up with the alarm signal after setting up warning time. This kind of method is suitable when the long interval is made, can also follow the result of this operation ， determine to wake time up in alarm next time temporarily, very flexible and convenient. ② The signal of using the system to be inherent is as reducing the pulse regularly. Use 50Hz worker power make reducing after having a facelift frequently, already omit the timer, gathered the corresponding signal for the phase place which measured the electric current signal at the same time, as Fig. 2 shows. External conditions are restored to the throne Send external condition pulse to and is restored to the throne the end son after having a facelift. To that abovementioned water wheels or the ammeter spend a pulse produced, can use Schmitt39。s trigger to have a facelift。 For writing down the instrument of the biggest or minimum， can use the window parator. In order to realize the electronization that is regulated， can use the electronic electric potential device, establish upper and lower limits with the order of the onechip puter. Reduce cycle and restored to the throne the high electricity at ordinary times In Fig3, restored to the throne the signal during high level Tr, the onechip puter is in the state of restoring to the throne, the procedure does not run, antiinterference ability is the strongest。 After the high level, the onechip puter begins to hold the conduct procedure. That is to say, are restored to the throne and suitable for the time that the procedure carries out during the low level Td of the signal, this time should be greater than the execution cycle of the procedure each