PROGRAMMABLE CONTROLLER

PROBLEM TO BE SOLVED: To provide a programmable controller for protecting a sequence program by preventing the sequence program stored in a program memory from being read out. SOLUTION: In the programmable controller, a main processing part 10 controls an apparatus in accordance with the sequence program stored in the program memory 11. The programmable controller is also provided with a service interface 14 for connecting an external device capable of communicating with the main processing part 10. The main processing part 10 is provided with a reading inhibition processing part 22 for inhibiting the reading of the sequence program stored in the program memory 11 from the service interface 14 to the external device. Since the reading of the sequence program from the service interface 14 to the external device can be inhibited, know-how of the sequence program can be prevented from being known by other persons and the sequence program can be prevented from being stolen. COPYRIGHT: (C)2007,JPO&INPIT