PURPOSE: To detect the abnormality even though the packing parts, etc., belong to a working system only by securing the synchronization among plural partial constitution blocks of pipeline types and at the same time executing the same process through the process blocks of different partial constitution blocks.

CONSTITUTION: The same clocks are inputted to an input interface part 1, an output interface part 3, and a partial constitution block 2 to secure the synchronization among these parts and block. In the block 2, each of blocks P0 - P2 consists of two process blocks. At the same time, these process blocks are processed in parallel with each other within a fixed time slot. Then the timing monitor, the comparison of output data, and the detection of errors are carried out. Then a signal is outputted to inform the detected abnormality to the outside. Thus the abnormality is detected even though the packing parts, etc., belong to a working system only.