| 摘要 |
<p>PURPOSE: To inexpensively provide a network supervising stem capable of flexibly corresponding to a change in a diagnostic method or the like and suppressing the increment of communication traffic in a network. CONSTITUTION: Respective programmable logic controllers(PLCs) 1, 2 are connected to a network 4 respectively through communication lines 12, 13 and a PLC 3 is connected to a network 5 through a communication line 14. In an FA network system connecting both the networks 4, 5 through a communication line 15, an abnormality detecting worm 20 to be optionally moved on the network through communication lines is prepared as an abnormality detecting means and abnormality diagnosis in each PLC is executed by the worm 20 moved to the PLC concerned.</p> |
