(controller area network) A protocol (ISO 11898) for serial bus networks, designed for the interconnection of smart devices (from multiple manufacturers) in smart systems and for real-time industrial applications. Originally developed for use in automobiles, CAN is now used in a variety of industrial automation control environments.
An open industry-standard communication protocol and device profile specification (EN 50325-4).
A programming unit that has 1 or more inputs and returns 1 or more outputs. FBs are called through an instance (function block copy with dedicated name and variables) and each instance has a persistent state (outputs and internal variables) from 1 call to the other.
Examples: timers, counters
A processor task that is run through its programming software. The MAST task has 2 sections:
oIN: Inputs are copied to the IN section before execution of the MAST task.
oOUT: Outputs are copied to the OUT section after execution of the MAST task.
For more information, refer to http://www.plcopen.org/.
A group of sections and subroutines, executed cyclically or periodically for the MAST task or periodically for the FAST task.
A task possesses a level of priority and is linked to inputs and outputs of the controller. These I/O are refreshed in relation to the task.
A controller can have several tasks.
