| 摘要 |
PROBLEM TO BE SOLVED: To disable a user of a user program to modify a system program and make it easy to modify the system program at need, to prevent hardware and software from becoming complicated, and to hold the use efficiency of a memory good. SOLUTION: Unique passwords are registered in a password registration part 34A by programming devices 1A and a password is incorporated in a program storage command including a program main body when the generated program PC2A is sent. The PC2A rewrites an old program into a new program in a program storage part 42 only when the program numbers and passwords both match each other at a program storing process part 41A and rejects the rewriting if the passwords are different although the program numbers match each other. |
