Book Image

PLC and HMI Development with Siemens TIA Portal

By : Liam Bee
Book Image

PLC and HMI Development with Siemens TIA Portal

By: Liam Bee

Overview of this book

With automation requirements on the rise, Siemens’ TIA Portal development environment is almost a necessity for any automation engineer. The Totally Integrated Automation (TIA) environment helps seamlessly integrate all things automation, from PLC hardware and software design to HMI development. This book helps you understand the tools available in the TIA toolbox and shows you how to write code effectively. The book begins by introducing you to the TIA environment, covering the layout and tools available. Once you’ve got to grips with the environment, you’ll find out how to create hardware to write programs against, including adding IO modules and assigning memory for input and output. Next, you'll develop logic in all of the languages that TIA Portal offers, such as Ladder, Function Block Diagram, and Structured Text (SCL) (note that Statement List is not covered as a deprecated language), as well as the newest language, Cause and Effect (CEM). You’ll also discover how to store standard code in libraries, creating a version control system that is easy to manage and aids standard design. Finally, following the PLC design chapters, you’ll learn how to develop HMI applications in TIA Portal’s latest unified hardware. By the end of the book, you'll be well equipped to use all of the features that TIA Portal V17 offers.
Table of Contents (21 chapters)
1
Section 1 – The TIA Portal – Project Environment
5
Section 2 – TIA Portal – Languages, Structures, and Configurations
11
Section 3 – TIA Portal – HMI Development
16
Section 4 – TIA Portal – Deployment and Best Practices

Retaining data in optimized and non-optimized blocks

When a PLC loses power, runtime variable data is lost and reset back to its default values, unless it is checked to be retained. Retained data persists after a power fail or a download to the PLC, and it only resets to its default values when a reinitialization occurs or a memory clear of the PLC occurs. If a variable needs to retain information, the Retain function needs to be selected in the corresponding data block or interface:

Figure 13.8 – The Retain checkbox

Figure 13.8 shows an example of four values set to Retain in a data block. Once the Retain box has been checked for some given data, the changes must be downloaded to the PLC. This will cause a reinitialization of the data.

Retaining data in instance data

Function blocks and associated instance data blocks can also have data retention set. However, there are more options involved, and it also depends on whether the function block...