Extrusion drive control system

For use with a drive unit including an electric drive motor and regulator therefor and providing analog condition information signals indicating a plurality of operating conditions of the drive unit, said operating conditions including drive rpm, armature voltage and armature current, a drive interface unit adapted to accept said analog condition information signals having any of a plurality of said of predetermined input characteristics and to provide corresponding digital signals having characteristics invariant with respect to the particular said input characteristics,

• said drive interface unit having
• analog signal input means for receiving from said drive unit a set of said analog condition information signals, said analog signal input means having selectable means connectable to said drive unit to receive said set of analog condition information signals having any of a plurality of predetermined input characteristics,
• analog signal output means for outputting to said drive unit analog control signals representative of a plurality of drive operating commands, said operating commands including on/off commands and speed set commands, said analog signal output means having selectable means connectable to said drive unit to output said analog control signals having any of a plurality of predetermined output characteristics,
• internal data bus means for carrying digital information signals, said digital information signals having characteristics generally substantially different from said predetermined input and output characteristics,
• input signal isolation means connected between said analog signal input means and said data bus, for providing, for each said operating condition, corresponding said digital signals in response to input said analog condition information signals, said digital signal characteristics being invariant with respect to input of said set of analog condition information signals having any of said plurality of predetermined input characteristics,
• output signal isolation means connected between said analog signal output means and said data bus means, for providing, for each said drive operating command, corresponding said analog control signals in response to said digital signals, said analog control signals having a selected one of said predetermined output characteristics, and
• command input means connected to said data bus means for inputting drive operating commands,
• data storing and channeling means connected to said data bus means and having timing means and digital information signal storage,
• said data storing and channeling means being responsive to said timing means successively to receive from said input signal isolation means said digital signals indicating said drive operating conditions and to store said digital signals in said digital signal storage,
• said data storing and channeling means being responsive to said input commands to control said analog signal output means to output said analog control signals indicating said input command.