| 摘要 |
PURPOSE:To easily and surely protect a control sequence program by inhibiting the operation of a program output means when any program output inhibit instruction is contained in the control sequence program. CONSTITUTION:When the content of a read step shows an MEMSW instruction to set the flag of a memory switch area 29 in an EEPROM 21, the flag of 16 bits is set by the following operand having hexadecimal 4 digits. When the operand is '8000', the read control flag of the memory switch area 29 is set to '1' and when the operand is '4000', the write control flag is set to '1'. Thus, since the memory switch area 29 can be set by the MEMSW instruction written in the sequence program, read or write can be easily inhibited by a software. |
