Control system for a storage/retrieval machine in an automated material handling system

A control system for controlling the operation of a storage/retrieval (S/R) machine in a material handling system, the S/R machine being directed by the control system to perform an ordered sequence of movements between addressable stations in response to a control command for the stacking and/or retrieving of material units, the control system comprising:

• input means for operator communication of a control command specifying an S/R machine operation:
• programmable processing means operatively coupled with the input means and responsive to an operator control command for directing the S/R machine to perform an ordered sequence of movements corresponding to the specific control command, the programmable processing means being controlled by a stored program and including,
• memory means for storing program instructions, and
• central processing means operatively coupled with the memory means and responsive to the stored program for executing the instructions to cause the S/R machine to perform the specified S/R machine operation,
• the memory means comprising a first memory block having a host control program of instructions encoded in an, elementary program language, and a second memory block having a user application program of instructions encoded in a non-elementary program, the central processing means including first means operatively coupled with the first memory block and the second memory block and being responsive to a selected instruction in the first memory block for accessing selected instructions in the second memory block,
• the first memory block including second means operatively coupled with the first means for emulating the selected instructions from the second memory block,
• the central processing means including third means operatively coupled with the second means for producing control signals for the S/R machine in accordance with the selected instructions from the second memory block,
• said first memory block being physically separate from the second memory block and being a read only memory.