Elevator control apparatus

An elevator control apparatus which comprises:

• main control means coupled to an elevator for producing a plurality of first elevator control signals and for periodically producing a reset signal, said main control means including a first special purpose computer device for generating said first elevator control signals and said reset signal, said first special purpose computer device including a stored elevator main control program;
• auxiliary control means coupled to said elevator for producing a plurality of second elevator control signals, said auxiliary control means including a second special purpose computer device for generating said second elevator control signals, said second special purpose computer device including a stored elevator auxiliary control program;
• timer means coupled to said main control means for repeatedly measuring a predetermined time period starting from the occurrence of said reset signal produced by said main control means and for generating an auxiliary control command signal upon the failure of said reset signal to reoccur prior to the end of said predetermined time period;
• and
• signal switching means interposed between the output of said main control means, the output of said auxiliary control means, and the control input of said elevator for alternatively coupling said first and said second elevator control signals to the control input of said elevator, said signal switching means being controlled by said auxiliary control command signal from said timer means.