controller 40 these controller output signals 108 for example provide signals controlling the injectors and hydraulic systems of the injection molding machine 10 the controller output signals 108 may be combined with controller input signals 112 from input terminals 110 for example being from sensors on the injection molding machine 10 and received at i o terminals of the programmable logic controller 98 to be used as inputs thereto the programmable logic controller 98 logically combines signals from controller output signals 108 and from controller input signals 112 according to its stored program on memory stick 104 using user selected logic and arithmetic instructions and state dependent counter and timer functions to produce vacuum control signals 114 the vacuum control signals 114 pass through terminal block 96 to valves 72 68 90 to control those and to the timers 100 and 102 to trigger the timers and to produce timer output signals that may be provided to the programmable logic controller 98 or directly to the valves 72 68 90 as additional vacuum control signals 114 in addition the programmable logic controller 98 may produce an output signal 116 forming one of the controller input signals 112 that may be received by the input terminals 110 of the terminal block 42 of controller 40 to provide control signals to.