Using a Framework for a PLC Project | Sofcontraining.com

Why should I use a framework for my control and automation projects?

Before we start looking at the reasons for using a common framework, I’ll start by explaining what it is I mean by it.

Simply, a framework is a piece of software or a library that provides generic or common predefined functionality. The framework is reusable and can be extended by a user in order to provide a bespoke / custom solution.

Advantages

Efficiency and Cost

The framework will typically provide up to around 50% of the application developments features thus resulting in a huge saving in time. In addition, the use of predefined, pre-tested code will dramatically reduce development and coding time.

Improved documentation and customer support.

Once again, the use of the software framework and predefined code will speed up the production of manuals as much of the content relating to common automation tasks can be written once and used time and time again.

Quality

The use of predefined , pre-tested code dramatically improves the quality of the software product, ensuring consistency and fewer programming errors.

I’m going suggest two frameworks.

The first shall cover PLC and the second HMI.

PLC Framework

The framework should be split into program areas covering,

• Version
• Constants
• Global Code and Startup
• Input Mapping
• Safety Interface
• Interlocks
• Recipe Handling, Engineering SP
• Data mapped from the HMI or SCADA
• Data mapped to the HMI or SCADA
• Device Handlers
• Alarm Handling
• Output Mapping
• Communications setup
• Statistics
• Any program sequences.

The picture below demonstrates this. The example shown was created using Mitsubishi GXWorks 2.

Note: The program naming does not dictate program flow as this can be set elsewhere.

 

HMI Framework

The HMI framework should incorporate the following generic features:

• Security – Predefined levels of access
• Multi Language Support
• Alarm Handling
• Logging
• Trending
• Common Icons, Pushbuttons and displays