Choose the programming language based on the kind of application you are building up. Function Block Diagram, Ladder Diagram, and Structured Text can be applied for logic of Add-On Instruction.
Every programming plc languages supported in software of RSLogix 5000 is aimed for different kinds of applications and styles of programming. Generally, Ladder Diagram performs simple logic Boolean, counters, and timers the fastest. Structured Text and Function Block Diagrams may be more proficient if you obtain benefit of the more highly developed process and drives instructions offered in those languages.
You can not evaluate times of execution for the similar Add-On Instruction written in dissimilar programming languages. There are basic differences on how the dissimilar languages perform and are collected.
Some instructions carry out only when rung condition n toggles from false to true. These are ladder instructions of transitional-relay. These instructions will not notice the transition rung-in to the state of false when used in an Add-On Instruction. The logic routine of Add-On Instruction no longer implements, therefore the instruction transitional does not sense the transition to the false state When the EnableIn bit is false. Extra conditional logic is required to handle triggering instructions of transitional included in an Instruction of Add-On.
Size of Instruction
Instructions of Add-On have one main logic routine that identifies the instruction behavior when carried out. This custom logic is like any other practice in the project and has no added restrictions in length. There are no borders on the In/Out parameters number. The data samples of maximum supported contain of Inputs, Outputs, and local tags is 2Mbs. The type size of data is shown on the bottom tab of the Local Tags and Parameters in the Definition of Add-On Instruction.
Add-On Instructions can just be revised offline. If the aimed functionality requirements to be adjusted in a running controller, think carefully if an Add-On Instruction is appropriate.
Add-On Instructions Nesting
Instructions of Add-On can identify other Add-On Instructions in their practices. This offers the capability to design more code of modular by making simpler instructions that can be utilized to make more complicated functionality by instructions of nesting. The instructions can be layered to 7-levels deep. The Add-On Instructions can not identify other practices via an instruction of JSR. You have to apply nested instructions if you require complicated functionality consisting of numerous routines.