CTI 2500-C100, Инструкция по установке и эксплуатации

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CTI 2500 Installation and Operation Guide V2.8 32
Subroutine Instructions
The subroutine instructions allow you to create and call RLL subroutines. They also include the
ability to call Special Function programs and subroutines.
Immediate I/O instructions
The immediate I/O instructions read or write to the physical I/O during RLL execution rather than
waiting for the normal I/O update to take place later in the controller scan. See CHAPTER 6 for
additional information regarding the scan timeline.
Miscellaneous
The RLL also contains instructions that allow you to turn on an output for a single scan (one
shot), read diagnostic data from Profibus, and execute a PID loop.
3.3 Special Function Programs and Subroutines
Special Function (SF) programs and subroutines provide a statement-oriented procedural
programming language. Using the Special Function instructions, you can derive solutions that
cannot be done in RLL or would require complex RLL programming.
SF programs can be called from an RLL program or from analog loop or alarm tasks. SF
subroutines can be called from RLL, SF programs, or other SF subroutines. SF programs and
SF subroutines use a common instruction set.
The number of Special Function programs and Special Function subroutines that can be
programmed depends on the product model. See Section 1.20.
Special Function Program instructions include the following groups:
Data Conversion
These instructions provide the capability to scale values and to convert between BCD and
binary format.
Math
Math instructions support both integer and real numbers. Operators include standard math
functions (add, subtract, multiply, divide, exponentiation, comparison, and bit operations) as well
as a unique LEAD/LAG function that can be used with cyclic applications.
Program Flow
These instructions alter the order in which instructions are executed. They include the ability to
call subroutines, to branch to a label, and to implement conditional branching (If, Then, Else).