The basic idea behind an Equipment Sequence Diagram is to run one Equipment Phase section of the PLC’s code – and then to switch over to running a different Equipment Phase section at the appropriate time. A simple analogy would be a flow chart – containing other flow charts.
The various Equipment Phases are programmed into separate “Steps” – and moving from one step to the next is controlled by a “Transition” element.
This is similar to the operation of a Sequential Function Chart – except that here the code within each step has been written using the Equipment Phase programming method.
If you need to understand this type of programming, we have troubleshooting exercises available – all based on our hands-on Boot Camp training approach.