| 摘要 |
<p>A modifier function block 54 adapted for use in a process control routine includes a series of processor implementable instructions that conditionally enhance or modify the functionality of a base function block 52 associated with the process control routine. The base function block includes a resettable branching point located within a set instructions used to perform a process control related operation. The branching point of the base function block has a pointer which, when set to a first value, causes another of the set of instructions within the base function block to be executed (to thereby bypass the execution of the modifier function block), and which, when set to a second value, causes the series of instructions within the modifier function block to be executed (to thereby alter the functionality of the base function block). In this manner, the modifier function block may be conditionally called, depending on the state of the base function block, to change the operation of the base function block or to leave the functionality of the base function block unaltered.</p> |
