| 摘要 |
PROBLEM TO BE SOLVED: To provide a programmable controller capable of holding data values on an internal register which are used for ladder calculation even when the power source is turned OFF while ensuring a high speed ladder calculation.SOLUTION: The programmable controller includes: a calculation processor that executes a ladder calculation; a static RAM having a first internal register which is used when the calculation processor executes a ladder calculation; and a nonvolatile RAM having a second internal register. The calculation processor executes the ladder calculation and copies the data value on the first internal register to the second internal register at end of scan of the ladder calculation.SELECTED DRAWING: Figure 2 |
