Abstract: A computer-implemented method and a computer-readable program for designing software applications for execution in a programmable logic controller includes determining whether a physical input is analog or discrete, and responsive to the physical input being analog, inputting a set of analog parameters, and responsive to the physical input being discrete, inputting a set of discrete parameters, and storing the parameters in a user parameter data table. The method includes executing a programmable logic controller application responsive to a set of user-defined parameters, including reading an input, and determining whether the input is in fault, and, responsive to the input being in fault, performing an operation from a group of operations consisting of an alarm and a shutdown.

Abstract: A computer keyboard having an output port through which scan codes are directed to a computer CPU over a cable, the keyboard of the kind having a touch activated membrane switch onto which one of a plurality of key layout overlays can be installed. Each of a plurality of different stored data tables is operable when selected to determine the particular scan code that is directed through the keyboard output port over the cable in response to a membrane switch being activated. Each overlay being coded in a way that can be read by an overlay code identification device which automatically operates in response to a coded key layout overlay being installed onto the keyboard to read the overlay code, which is then used by a data table selector to select a particular data table for use with the installed overlay.