Industrial controller permitting program editing during program execution

A method of editing an pre-existing section of a real-time control program that may be executed by an industrial controller, the pre-existing section including at least one instruction to be edited, the method inserting a new section after the pre-existing section and comprising the steps of:

• a) loading the real-time control program including the pre-existing section into a first area of memory;
• b) loading the new section into a second area of memory;
• c) inserting a first jump instruction in the second area of memory at the end of the new section, the first jump instruction, when executed, causing the industrial controller to jump to a second instruction of the pre-existing section after a first instruction of the pre-existing section;
• and
• d) during the execution the real-time control program, replacing a first instruction of the pre-existing section with a second jump instruction which, when executed, causes the industrial controller to jump to a first instruction of the new section.

An industrial controller used to execute a real-time control program of instructions collected into logical rungs, each rung which may only be executed as an entirety, the first instruction of each rung being a start rung instruction, the control program including at least one pre-existing rung to be edited, the industrial controller comprising an electronic computer executing a stored program to provide the following:

• a) means for loading the instructions of the real-time control program into a first area of memory;
• b) means for executing the control program to control an industrial process in real-time;
• c) means for loading instructions of a new rung into a second area of memory;
• d) means for inserting a first jump instruction in the second area of memory at the end of the new rung, the first jump instruction, when executed, causing the industrial controller to jump around the pre-existing rung in the first area of memory;
• and
• e) means for, during the execution of step (b), replacing an instruction preceding the start rung instruction of the pre-existing rung in the first area of memory with a second jump instruction which, when executed, causes the industrial controller to jump to a first instruction of the new rung in the second area of memory.

An industrial controller used to execute a real-time industrial control program of instructions collected into logical rungs, each rung which may only be executed as an entirety, the first instruction of each rung being a start rung instruction, the control program including at least one pre-existing rung to be edited, the industrial controller comprising an electronic computer executing a stored program to provide the following means:

• a) means for loading the instructions of the real-time control program into a first area of memory;
• b) means for executing the control program to control an industrial process in real-time;
• c) means for loading instructions of a new rung into a second area of memory;
• d) means for inserting a first jump instruction in the second area of memory at the end of the new section, the first jump instruction, when executed, causing the industrial controller to jump to a second instruction of the pre-existing section after a first instruction of the pre-existing section;
• and
• e) means for during the execution of the real-time control program, replacing a first instruction of the pre-existing section with a second jump instruction which, when executed, causes the industrial controller to jump to a first instruction of the new section.

An industrial controller used to execute a real-time control program of instructions collected into logical rungs, each rung which may only be executed as an entirety, the first instruction of each rung being a start rung instruction, the control program including at least one pre-existing rung to be edited, the industrial controller comprising an electronic computer executing a stored program to provide the following:

• a) means for loading the instructions of the real-time control program into a first area of memory;
• b) means for executing the control program to control an industrial process in real-time;
• and
• c) means for, during the execution of step (b), replacing a start rung instruction of the pre-existing rung in the first area of memory with a jump instruction which, when executed, causes the industrial controller to jump to a start rung instruction of the following pre-existing rung.