| 摘要 |
PURPOSE:To grasp immediately the factor of a trouble from the I/O state and the data on a single circuit including an abnormality instruction at that time point together with reference to a display device in case the abnormality instruction is executed, by using an abnormal state display means. CONSTITUTION:When a trouble or a bug is produced, the data on a single circuit including an abnormality instruction as well as the I/O state are displayed on a display device to know immediately the factor of the relevant trouble. Here a keyboard 1 is provided together with a memory 2, a CRT 3, an input/output unit 4, and a CPU 5. The memory 2 contains a system program memory which stores a system program that provides the abnormality instruction retrieving function, the I/O state saving function, the abnormal state display function, etc. to the CPU 5, a user program which gives the sequence control to an equipment to be controlled, and an I/O memory serving as a working area of the CPU 5. While an FAL/FALS instruction table 6 and an I/O state saving area 7 are provided at a part of the I/O memory. |
