Programming method and programming unit for programmable controller.

摘要

A programming system for a programmable controller is improved by providing for. automatic retrieval of the execution programs corresponding to application instructions which do not form a part of the basic program instruction set. Application instructions embedded within a sequence program are recognized and their names are displayed on the operator's display (24). The corresponding execution instructions are retrieved and subsequently combined with the sequence program while the operator monitors the retrieval operation on the display (27). After the execution instructions have all been copied over into the memory (16) for the sequence program, the application instructions may optionally be rewritten as standard subroutine instructions including the head address of the given set of execution instructions, to avoid the need for a symbol table to interpret between application instruction names and the corresponding head address for the execution instructions.