| 摘要 |
PURPOSE:To save the capacity of a power source by reading an input signal from an input part cyclically and by supplying a current from the power source part to the input part synchronizing with the readng operation. CONSTITUTION:To control currents from a power source part 7 to respective input parts 5A-5K connected to the power source part in common, each input part is provided with a current supply controlling circuit which consists of photoisolators 16 and 11 and a switching TR. To the input parts 5A-5K, a cyclic control part 21 supplies cyclic driving signals DV1-DVK successively for cyclic driving signal control through input buffer controlling parts 22A-22K. When a TR17 is turned on synchronizing with a driving control signal CD, a current is supplied through some of process input signals SA1-SAn in on-states to sent input signals IA1-IAn. When the TR17 is off, the capacity of the power source equivalent to the input circuits is needed since the power source part 7 is nearly in a no-load state. |
