| 摘要 |
PURPOSE:To inhibit the input of a third person even in case an operator leaves his/her seat by registering a cipher to an input device when the input is inhibited and then supplying the cipher when the inhibition of input is released. CONSTITUTION:An operator leaves his/her seat and the input is inhibited for a third person. In such a case, the operator pushes a lock button 11 of a key unit 1 to feed a cipher from a key unit 2. A control circuit 35 detects the input of the cipher and sets an FF31 to write the cipher to a cipher memory circuit 36. When the FF31 is set, an AND gate 33 is turned off and a lamp drivng circuit 4 turns on a lamp 41. Under such conditions, the signal sent from the unit 1 is not accepted by the circuit 35 and therefore never sent to a CPU10. In a lock release mode the circuit 35 compares the cipher given from the unit 1 with the cipher read out of the circuit 36 through a comparator 37. When coincidence is obtained from said comparison, the FF31 is reset and the gate 33 is turned on to turn off the lamp 41. |
