US 4,302,820 AGranted

Dual language programmable controller

AssigneeAllen-Bradley Company, Inc.

InventorsOdo J. Struger, Ronald E. Schultz, Barry E. Sammons

Life of this patent

Estimating the term…

Loading patent…

Abstract

A programmable controller includes a microprocessor which operates in response to machine instructions stored in a read-only memory. A control program comprised of programmable controller-type instructions is stored in a random access memory. These are executed by translating their operation codes into the starting addresses of corresponding sets of machine instructions. In addition, one or more "universal instructions" may be contained in the control program, and when these are read from the random-access memory, they are translated to enable the microprocessor to execute a user defined set of microprocessor machine instructions. These user defined machine instructions may be stored in a read-only memory or they may be stored in the random access memory with the control program. The programmable controller may thus effectively be programmed in two languages, a programmable controller language and a microprocessor machine language.

Claims11

Dependent claims

In a programmable controller having a memory which stores a control program comprised of a plurality of control macroinstructions and a processor which includes a microprocessor, said processor being coupled to said memory and being operable to sequentially read the control macroinstructions from the memory and perform a function indicated by each control macroinstruction by translating it into a set of stored machine instructions which are executed by said microprocessor, the improvement therein comprising:

means coupled to said processor for storing a machine language routine comprised of a unique set of machine instructions, which when executed by said microprocessor carry out a function;
means coupled to said processor for storing an interpreter routine comprised of machine instructions, which when executed by said microprocessor, direct it to:
(a) store the contents of one internal microprocessor register in a selected storage location;
(b) execute said machine language routine;
(c) restore the contents of the internal microprocessor register by transferring said contents from said selected storage location;
and
(d) fetch another of said control macroinstructions from said memory;
and
translator means coupled to said memory and said processor for sensing a selected one control macroinstruction read from said memory and enabling the microprocessor to execute said stored interpreter routine, whereby the processor executes a control program comprised of both control macroinstructions and said selected one control macroinstruction.

6 more elements

A programmable controller which comprises:

a memory which stores a control program comprised of a plurality of control instructions each having an operation code which defines a specific fixed function to be performed, said memory also storing as part of said control program a universal control instruction having a unique operation code;
processor means coupled to said memory and being operable to sequentially read the instructions in said control program from said memory and perform the functions indicated by their operation codes, said processor means including:
(a) a microprocessor which executes machine instructions to perform functions;
(b) means coupled to the microprocessor for storing a plurality of interpreter routines, each comprised of a set of machine instructions, which when executed by the microprocessor, cause it to perform a function indicated by an operation code in one of said control instructions;
(c) means coupled to the microprocessor for storing a machine language routine comprised of a set of selected machine instructions;
and
(d) translator means coupled to said memory and said microprocessor for selecting one of said interpreter routines for execution by said microprocessor in response to each control instruction operation code read from the memory and being operable to select said machine language routine for execution by said microprocessor in response to the unique operation code in the universal instruction read from the memory;
wherein the functions performed in response to the interpreter routines define a programmable controller instruction set and the functions performed in responses to the machine language routine is defined by the user of the programmable controller.

5 more elements

Dependencies are inferred from the claim text.