Patent ID: 7505875

Claim:
A monitor system comprising: a programmable controller for executing a user program to carry out a control; a data collecting unit connected to said programmable controller for collecting variable data of said programmable controller; and a monitor device connected to said data collecting unit through a communication line; said data collecting means including collecting means for collecting real variable data in the calculation formula stored in said memory means and any other real variables from said programmable controller; said monitor device including: memory means for storing a preliminarily defined virtual variable apart from said user program of said programmable controller and from said variable data of said programmable controller and a calculation formula using one or more real variables for obtaining said virtual variable; calculating means for carrying out a calculation according to the calculation formula stored in said memory means based on the real variable data collected by said collecting means; and displaying means for displaying correspondence of the real variables collected by said collecting means and the result of the calculation by said calculating means as waveforms on a display device; wherein said collecting means includes means for collecting data on the real variables from a memory of said programmable controller based on mapping data in synchronism with the cycle time of said programmable controller and means for transmitting the collected data on the real variables to said monitor device; wherein said calculating means includes means for obtaining the data on the real variables from said collecting means and means for generating a data array of virtual variables by substituting the obtained data into the calculation formula stored in said memory means; and wherein said displaying means displays the obtained data on the real variables from said collecting means as waveforms on said display device.