INPUT/OUTPUT AND DIAGNOSTIC ARRANGEMENTS FOR PROGRAMMABLE MACHINE CONTROLLERS HAVING MULTIPROGRAMMING CAPABILITIES

摘要

INPUT/OUTPUT AND DIAGNOSTIC ARRANGEMENTS FOR PROGRAMMABLE MACHINE CONTROLLERS HAVING MULTIPROGRAMMING CAPABILITIES A programmable controller includes a random access memory for storing signals relating to a plurality of programs executable in the controller. A portion of the memory addressing is zoned for enabling one or more programs to have exclusive access to that zone. The addressability of input/output registers, diagnostic registers and selected other units of common interest to all such programs are addressable in each of the plurality of zones as if such registers were uniquely assigned to such respective memory zones.