Control Expert supplies reusable blocks for jobs such as timers and PID control. These EFBs (Elementary Function Blocks) provide defined functions for timing, counting, communication and control. The Library Manager lets you inspect the available block types and versions alongside reusable DFBs. Browse the example library, then operate the simulated TON timer and compare its inputs with its output.
Select a block from the library palette on the left to read its description. The TON example also runs as a simulation: toggle IN and watch the elapsed time ramp to the preset, then Q become TRUE. Turning the input off resets this example, so you can repeat the timing cycle and inspect each stage.
An EFB instance has its own instance data, so fifty TON instances can keep independent timer states. Inspect each block type's version when managing library changes. An update changes the block definition used by the project and needs deliberate checking before it is used on equipment.
🧰 EFB provides a supplied block implementation, for example a timer, counter or PID controller. The libraries also contain communication functions such as READ_VAR/WRITE_VAR; these are not all EFBs. Read each function or block's interface and operating conditions before using it. A supplied implementation does not validate the application you build around it.
🧠 DFB contains logic defined for your application in a supported language (Track 04). Like an EFB, a DFB can be instantiated with separate data. You choose the interface and behaviour of the reusable block, then test it in the application where it will run.
Maintain a project library of checked DFB definitions and identify the versions used by each machine project. Shared definitions reduce repeated code, but an update still needs to be selected, built and checked for the receiving project. Library management differs between vendors; the shared idea is to control which reusable definition a project uses.
You need to keep a fan running for 30 seconds after its start signal drops (a run-on timer). Which EFB?