Programming standardization unifies, improves operator experience

Industrial equipment and machines have more capabilities than ever, in today’s landscape of high-tech devices, increasing the criticality of a consistent end user operations experience from machine to machine, and plant to plant, and programming software can help. Without consistency, it can be difficult to stay on top of the nuances of many complex system interfaces, leading to operational failures and unplanned downtime, or worse, safety incidents.

Programmers for programmable logic controllers (PLC) and human-machine interfaces (HMIs) play a critical role in maintaining operator familiarity among systems to reduce these adverse outcomes. By implementing consistent code and interfaces on machines throughout a plant floor and an enterprise, they make equipment simpler to operate and easier to troubleshoot.

In the past, programmers had to exercise hyper-vigilance to maintain procedural consistency from machine to machine because program management was almost purely manual. However, modern integrated automation suites with built-in standard code libraries are simplifying and automating this process — especially in the areas of system diagnostics and alarm generation — providing programmers with the tools they need for standardizing and improving the operator experience.

Standardize machine operational procedures

Charting the course toward operational and maintenance consistency requires standardization and planning. Manufacturers are realizing the need to standardize procedures from engineering to deployment, but implementation is often difficult.

To help organizations overcome this challenge, modern integrated automation suites enable machine builders and end users to standardize and maintain consistent machine operational procedures. Standardization simplifies business and technical process management and empowers operators to safely meet production goals.

Bringing mechanical, electrical, and automation engineering into alignment early in a project lifecycle also is critical for effective outcomes. Integrated automation suites enable parallelization of work steps across disciplines to provide this capability (Figure 1).

This reduces total commissioning time while simultaneously enhancing product quality via cross-disciplinary quality checks, and by digital simulations for virtual commissioning and other tasks.

Software tools for automation standardization

Intelligent use of the right tools is essential throughout standardization in this complex landscape. With the right software, users can import and export electrical and mechanical drawings directly into the automation suite to automatically update system control and maintain design consistency across all engineering disciplines (Figure 2). This also saves time spent in coordination efforts and speeds commissioning.

Integrated automation suites also enable programmers to develop and maintain standardized automation program libraries, with direct links between hardware components and their software instructions (Figure 3).

Several of these automation objects are built into the software suite and pre-verified, resulting in less time spent testing and troubleshooting. Developers can also create new objects, and then test their functionality through virtual commissioning or digital twin simulation.

All automation objects can be reused throughout one project or across multiple projects, reducing development time and ensuring consistent functionality every time a particular hardware component is used. With production engineering configurations and the proper connectivity, automation projects also can be configured to perform automatic object updates based on the master library. This creates consistency during development and the operating experience, which saves time troubleshooting complicated issues and leading to higher-quality production.

Another tool aiding programmers provided by modern integrated automation suites is automatic generation of PLC code and simple HMI layouts, including data views and dashboard configurations. This makes program development reliable while providing end users with operational procedures and visualization components for monitoring production efficiency.

Effectively chart automation program structure

The quality of planning can make or break a project’s success. The same can be said for PLC programming. There are some decisions that must be made early in the programming process to ensure standardization down the road (Figure 4).

The first major topic is readability. Developers must define a scheme for tag identifiers and enterprise-wide asset identification nomenclature to keep equipment and devices organized.

Developers also must consider programming and equipment maintenance requirements, and then create libraries capable of versioning in a user-friendly manner, with equipment templates to aid operations and maintenance personnel in troubleshooting field problems. The programming language should also be determined at this stage. Ladder diagram, function block, structured text (ST) and sequential function charts (SFCs) each have advantages and disadvantages for code creation, expansion, and troubleshooting—and one or more of these languages can be used.

Once the programming base is determined, developers must next define interfaces for human interaction with machines, including HMI graphics, alarming and alerting and historical data visualization and analysis. This also is the point where inter-device communication schemes are defined for transferring data around the plant floor.

Developers must make a plan for automation object reuse, ensuring objects are modular and can be implemented in multiple programs seamlessly. Good standardization practice also requires thorough documentation at this stage so the standards library retains value over time and endures through staff turnover.

System diagnostics: Baseline for automation library standardization

Diving into the weeds, programming standards must particularly deal effectively with system diagnostics. These are the universal indicators that signal machine control system health and status for PLCs and networked devices. These indicators provide notice to plant staff when basic equipment and device functionality breaks down due to problems such as communication faults, module faults, power issues, and safety concerns.

While most networked devices come with automatic methods for alerting users to these sorts of conditions onboard, translating these issues to alerts or alarms in the larger automation system often requires extra manual effort.

When connecting multiple machines and devices in a plant or across an enterprise, ensuring uniform system diagnostics and alarm management is critical for efficient operation. Oftentimes, however, these essential facets are not handled consistently from machine to machine, creating misunderstandings, delays, and unplanned downtime.

This lack of uniformity is often a result of early deficiencies in the standardization of engineering and programming. While one machine may utilize a particular scheme of interlock checks and means of flagging basic faults, another may be designed differently. Through careful planning and programming, it is possible to consistently implement machine diagnostic alerting across multiple machines.

Consistency for PLCs, HMIs, edge devices, workstations

To maintain uniformity across machines, integrated automation suites automatically generate system diagnostic and alerting schemes based on the hardware configuration, reducing time-consuming and error-prone program declarations. This provides consistent alerting and alarm readout among PLCs, HMIs, edge devices, plant workstations, webservers, and remote sessions through the cloud.

With integrated automation suites, these alarm readouts are automatically generated, enabling quick error identification and displaying fault messages with location and cause.

Because these diagnostics are generated automatically rather than manually programmed, changes to the hardware configurations automatically update system diagnostic infrastructure across a connected enterprise. Handling system diagnostics consistently across an enterprise lays the foundation for all programming standardization.

Using an integrated automation suite saves 30% programming time

An original equipment manufacturer (OEM) of crosscut saws improved its production systems and enhanced its global customer service by standardizing on one automation provider’s PLCs, HMIs, and drives, bringing development and operations under one integrated automation software suite.

By using automatic system diagnostic and alarm generation in the hardware configuration tool, the OEM reduced programming time by 30%. On top of the automation hardware’s intrinsic reliability, this empowered the saw manufacturer to provide end users with in-depth troubleshooting from the HMI.

Using the integrated system diagnostic view, the OEM’s end user customers can self-service many issues, and when problems are escalated to the OEM, the HMI’s clear display of system alarm conditions makes resolving end users’ issues much quicker. This results in less downtime for end users and fewer support calls to the OEM.

Because of the central automation object library, version control is simpler for the machine’s programmers. When updates are made to a block of code, developers can easily identify which projects contain the update and which do not, based on the automation object version in use, and can then automatically update all existing instances.

Integrated automation suite: 10 advantages

When programming automation systems, best practices dictate careful application and desired outcome consideration prior to diving into the code. Through this deliberation, standardization improves project development and operation lifecycles.

Advantages of standardization with an integrated automation software suite for manufacturers include:

1. Software becomes more transparent for the users, easing development efforts.
2. Quality of the software is increased, improving reliability and maintainability.
3. Errors are significantly reduced because automation programs use enterprise-wide program components proven prior to commissioning.
4. Expenditures for service and maintenance are reduced.
5. Diagnostics and troubleshooting are simplified.
6. Training requirements are minimized.
7. Data exchange among machines is simple and well-defined.
8. Documentation is manageable and clearly defines automation component behavior.
9. PLCs draw from a centrally-managed library of objects, creating uniformity in programming from machine to machine.
10. HMIs across a plant use consistent graphics, symbols, and terminology to improve the operator experience.

Machine builders and integrators can help their end user customers by standardizing automation program libraries. Using an integrated automation suite means developers spend less time creating schemes for low-level device diagnostics and alarming. This provides increased opportunities to improve the operator experience and refine machine functionality through cross-disciplinary optimization efforts.

John DeTellem is the TIA Portal product marketing manager for Siemens Industry in the U.S. Edited by Mark T. Hoske, content manager, Control Engineering, CFE Media, mhoske@cfemedia.com.

KEYWORDS: PLC programming, integrated automation programming software

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