| 摘要 |
<p>PURPOSE:To improve efficiency by providing an external detection means which detects an arithmetic interruption and informs this after restart of the arithmetic and an external storage means which stores the sequence state after turning it into the numerical value. CONSTITUTION:The relevant sequence state is turned into the numerical value at an arithmetic part 10 and this numerical value is stored in an external storage means 13 via a process output part 11b. A power hit of a digital controller 8 is detected by an arithmetic interruption detection means 12, and a signal (i) is sent to a process input part 11a. In an arithmetic operation carried out right after the recovery of a power supply or right after the switch to the standby side of a duplex controller, the part 10 inputs the signal (i) via the means 12 and inputs the signal outputted from the means 13 via the part 11a to carry on the control based on the value N. Thus it is possible to prevent the reversion of a sequence due to a data updating delay as well as the lost of the sequence state due to a power hit without attaining a complicated constitution of system nor increasing the system cost.</p> |
