Common PLC Retrofit Paths in Roll Forming Machines — Delta → Siemens, Omron → Allen-Bradley, Legacy → Modern

Introduction — Why PLC Retrofits Are Common in Roll Forming Machines

Roll forming machines are long-life industrial assets. It is common for the mechanical parts of a machine to remain productive for 20–30 years, while the original control system becomes obsolete after 10–15 years.

As PLC platforms age, several problems begin to appear:

• spare parts become unavailable
• programming software becomes unsupported
• system reliability decreases
• communication with modern devices becomes difficult

When these issues occur, machine owners often perform a PLC retrofit, replacing the old control system with a modern automation platform.

Retrofits allow manufacturers to extend the life of roll forming machines while improving automation capabilities.

Several retrofit paths are particularly common in the roll forming industry.

Typical Reasons for PLC Retrofits

PLC retrofits usually occur for one or more of the following reasons.

Obsolete Hardware

Manufacturers eventually discontinue PLC platforms.

When this happens:

• spare parts become difficult to obtain
• repair costs increase
• downtime risk increases

Limited Technical Support

Some PLC systems may be uncommon in certain regions.

This creates problems such as:

• lack of trained technicians
• difficulty obtaining programming software
• limited documentation availability

Upgrading Machine Capability

New control systems may provide features not available in older systems.

Examples include:

• advanced motion control
• improved networking
• better diagnostics
• remote monitoring capability

Upgrading the PLC can significantly improve machine performance.

Retrofit Path 1 — Delta PLC to Siemens PLC

Why This Retrofit Happens

Many roll forming machines built in cost-sensitive markets use Delta PLC systems.

Although Delta controllers are reliable, some manufacturers eventually upgrade to Siemens platforms for several reasons.

Typical reasons include:

• better global support
• stronger motion control integration
• compatibility with European automation standards

Machines exported to Europe are particularly likely to receive this upgrade.

Typical Retrofit Scope

A Delta → Siemens retrofit usually involves replacing:

• PLC CPU controller
• input/output modules
• HMI interface
• communication network

The new system typically uses Siemens controllers with integrated motion control capabilities.

Advantages of the Upgrade

Benefits may include:

• improved diagnostics
• stronger communication networks
• better long-term support

This retrofit is common when machines are upgraded for higher production requirements.

Retrofit Path 2 — Omron PLC to Allen-Bradley

Why This Retrofit Happens

Some machines originally built with Omron PLC systems are upgraded to Allen-Bradley controllers, particularly when machines are installed in North America.

Allen-Bradley automation systems from Rockwell Automation are widely supported across American manufacturing industries.

Reasons for this retrofit may include:

• technician familiarity with Allen-Bradley systems
• improved support networks
• compatibility with existing factory automation

Typical Retrofit Scope

This retrofit typically includes replacing:

• PLC controller hardware
• HMI operator interface
• communication network components

Servo drives may also be replaced if the machine requires integrated motion control.

Advantages of the Upgrade

Advantages include:

• easier technician support in North America
• improved integration with other automation systems
• easier spare parts availability

For machines operating in the United States, this upgrade often simplifies long-term maintenance.

Retrofit Path 3 — Legacy PLC Systems to Modern Platforms

What Are Legacy PLC Systems?

Many older roll forming machines still operate with early PLC platforms from the 1990s or early 2000s.

Examples may include:

• early modular PLC systems
• discontinued proprietary controllers
• relay-based control systems upgraded with basic PLCs

These systems often lack modern communication capabilities.

Why Legacy Systems Are Replaced

Legacy systems may cause several problems:

• spare parts no longer available
• outdated programming software
• unreliable hardware

When these issues occur, upgrading to a modern PLC platform becomes necessary.

Typical Modern PLC Platforms Used

Common replacement platforms include:

• Siemens automation systems
• Allen-Bradley controllers
• Mitsubishi PLC systems

These modern platforms provide improved performance and long-term support.

Additional Retrofit Paths in Roll Forming Machines

Other retrofit paths are also common depending on the machine origin and target market.

Examples include:

Mitsubishi → Siemens

Often occurs when Asian-built machines are upgraded for European factories.

Delta → Allen-Bradley

Common when low-cost machines are upgraded for North American production environments.

Legacy Relay Control → Modern PLC

Older machines sometimes use relay-based logic that is replaced with modern PLC systems.

Components Typically Replaced in PLC Retrofits

A PLC retrofit usually includes several system upgrades.

Typical replacement components include:

• PLC CPU controller
• digital I/O modules
• analog I/O modules
• HMI operator interface
• communication network hardware

Additional upgrades may include:

• servo drives
• VFD drives
• safety control systems

The scope depends on the condition of the existing automation system.

Commissioning a Retrofit System

After installation, the new control system must be commissioned.

Typical commissioning steps include:

1. verifying input signals
2. testing output devices
3. configuring communication networks
4. calibrating encoder length measurement
5. testing machine motion

Production testing should begin at low speeds before full operation.

Benefits of PLC Retrofits

Retrofits provide several important benefits.

These include:

• improved reliability
• better diagnostics
• easier spare parts sourcing
• compatibility with modern automation systems

Retrofitting the control system can extend the life of a roll forming machine by many years.

Planning a Retrofit Project

Successful retrofit projects require careful planning.

Important planning considerations include:

• machine documentation availability
• compatibility with existing drives and sensors
• technician training requirements
• spare parts availability

A well-planned retrofit minimizes production downtime during installation.

FAQ — PLC Retrofit Paths

Why do roll forming machines need PLC retrofits?

PLC systems become obsolete over time, making spare parts and software difficult to obtain.

What is the most common PLC retrofit upgrade?

Common upgrades include replacing legacy PLC systems with modern Siemens or Allen-Bradley platforms.

Why upgrade from Delta PLC systems?

Some manufacturers upgrade Delta systems to improve motion control capabilities and global technical support.

Why convert Omron PLC systems to Allen-Bradley?

This often occurs in North America where Allen-Bradley automation systems have strong support networks.

How long does a PLC retrofit take?

Retrofit projects may take several days to several weeks depending on machine complexity.

Does a PLC retrofit improve machine performance?

Yes. Modern control systems provide faster processing, better diagnostics, and improved automation capability.