Abstract: A system for displaying alphanumeric messages has a display device with a row of character stations at each of which a character may be created for display in response to a set of signals applied to the character station. A memory device stores a plurality of message fragments and a real time means provides a plurality of real time message fragments respectively representing a corresponding plurality of real time conditions. A control circuit in response to certain input conditions selects one stored message fragment and one real time message fragment and converts them to sets of signals applied in one to one relationship to the character stations to cause the display of a meaningful complete message by the display device.

Abstract: A programmer or switching apparatus produces an ON and OFF valued control signal for turning an associated controlled component ON and OFF at preselected points in the variation range of a reference variable. The apparatus includes a reference transducer for converting the reference variable into a reference signal representing the variable. A pair of set-point devices provide a pair of set-point signals which are compared with the reference signal to define operating points at which the control signal switches between its ON and OFF values. The apparatus has the versatility of allowing, by merely setting the set-point devices and without making any circuit changes, the first transition of the control signal to be either from ON to OFF or from OFF to ON as the reference variable increases from its minimum to its maximum value.