Control unit having indicators with pushbuttons - which are on front plate fixed to circuit board with function programming switches

摘要

The control unit joins with other identical units to form a control panel and consists of a narrow front plate with pushbuttons in line along (or down) it. The front plate is attached to a circuit board which slides into a rack containing other identical units. The functions performed by the pushbuttons are determined by programming switches (44) on the circuit board -- i.e. these switches alter the conducting-path connections on the board to accord with the desired function. The programming may be achieved using a microprocessor serving several such units in a rack.