MONITOR SYSTEM OF PROGRAMMABLE CONTROLLER

摘要

PURPOSE:To attain a monitor system of a programmable controller with high accuracy by providing a work area to which the images are saved when the conditions are satisfied for monitor stop. CONSTITUTION:A programmable controller 1 contains an image memory 5 and a control RAM4. The RAM4 contains a work area 4a where the addresses on the memory 5 that monitors the minitor stop conditions together with the 1st and 2nd save work areas 4b and 4c. Then the registration is carried out to the area 4a before the monitor is started to check whether the monitor stop conditions are satisfied or not. If said conditions are not satisfied, the contents of the memory 5 are stored to the area 4b. While the contents of the memory 5 are stored to the area 4c when said conditions are satisfied. Then the contents of the memory 5 are read out by a monitor device 7 and then checked every scan. Said contents are replaced when no conditions are satisfied, and the next monitor is repeated.