| 摘要 |
PURPOSE:To inform an attendant of the fault by the lighting display of a lamp and to achieve safe operation and recovery from a fault in its early stage, by discriminating whether a D/A-converted analog output is proper in comparison with a digital value, when controlling equipment to be controlled by performing the D/A conversion of a command value from a control center. CONSTITUTION:A command value from the transmitting circuit 52 of a control center equipment is received by the receiving circuit 53 of a controlled-center equipment and converted into an analog signal A0 by a D/A converter 55 throug a storage circuit 54, and the analog signal is supplied to an equipment D to be controlled. Control results from the equipment D are inputted to an input circuit 11 and analog value A01 from the converter 55 is applied to the circuit 11. During the halt period of a converter 14, the output of a scanning circuit 13 is digitalized by an A/D converter 14, whose output is compared with error permissible range to operate an error counter 43, whose output is applied to a gate circuit 15 through the circuit 13. This circuit 15 is controlled by the output of the converter 14 to send its output of the control center equipment, thereby letting an attendant know a fault by turning on and off a lamp. |
