Network Drops on Roll Forming Machines — PROFINET & EtherNet/IP Intermittent Communication Faults

Introduction — Why Network Stability Is Critical in Roll Forming Automation

Modern roll forming machines rely heavily on industrial Ethernet networks to connect automation devices.

These networks typically connect:

• PLC controllers
• HMI operator panels
• servo drives
• VFD drives
• remote I/O modules
• safety controllers.

Two of the most common industrial communication protocols used in roll forming machines are:

• PROFINET
• EtherNet/IP.

When network communication becomes unstable, the machine may experience intermittent faults that are difficult to diagnose.

Typical symptoms include:

• random machine stops
• drives dropping offline
• I/O communication faults
• HMI communication errors.

Understanding the causes of network instability is essential for maintaining reliable production.

Overview of Industrial Ethernet Networks

Industrial Ethernet networks are designed to provide fast and reliable communication between automation devices.

Unlike office networks, industrial networks often operate in real-time environments.

The PLC exchanges data with other devices continuously.

Examples of exchanged data include:

• motor speed commands
• encoder feedback signals
• sensor input status
• safety signals.

If communication is interrupted, the PLC may stop machine operation to prevent unsafe conditions.

What Is PROFINET

PROFINET is a real-time industrial Ethernet protocol widely used in automation systems.

It is commonly used with PLC platforms such as Siemens systems.

PROFINET allows high-speed communication between devices such as:

• distributed I/O modules
• servo drives
• operator panels.

The protocol is designed to support deterministic communication required in machine control.

What Is EtherNet/IP

EtherNet/IP is another industrial Ethernet protocol commonly used in automation.

It is widely used with controllers such as Allen-Bradley systems.

EtherNet/IP enables communication between devices such as:

• PLCs
• VFD drives
• remote I/O modules
• safety devices.

Like PROFINET, EtherNet/IP supports real-time control communication.

Symptoms of Intermittent Network Drops

Intermittent communication failures can produce various machine faults.

Common symptoms include:

• PLC communication alarms
• servo drives randomly disconnecting
• remote I/O modules showing communication faults
• HMI displays freezing temporarily.

These issues may occur sporadically and disappear after restarting the machine.

This makes them difficult to diagnose.

Common Cause 1 — Damaged Ethernet Cables

Ethernet cables in industrial environments are often exposed to harsh conditions.

Possible damage sources include:

• vibration
• sharp edges
• excessive bending
• cable crushing.

Even minor cable damage can cause intermittent signal loss.

Technicians should inspect cables carefully for physical damage.

Industrial vs Standard Ethernet Cables

Industrial Ethernet cables are designed to withstand harsh conditions.

They typically include:

• stronger insulation
• shielded wiring
• oil-resistant jackets.

Using standard office Ethernet cables in industrial machines may lead to communication problems.

Loose Network Connectors

Loose connectors are another frequent cause of network drops.

Industrial machines experience constant vibration.

Over time, Ethernet connectors may loosen.

Loose connectors can interrupt communication briefly, causing intermittent faults.

Technicians should check connectors for proper locking.

Electrical Noise Interference

Roll forming machines contain many sources of electrical noise.

Examples include:

• VFD motor drives
• servo drives
• hydraulic solenoid valves.

These devices generate electromagnetic interference.

If network cables are poorly shielded or improperly routed, noise may disrupt communication signals.

Proper Cable Routing

To minimize interference, network cables should be routed carefully.

Best practices include:

• separating Ethernet cables from motor power cables
• using shielded industrial Ethernet cables
• grounding cable shields properly.

Proper cable management significantly improves network reliability.

Industrial Network Switch Problems

Many roll forming machines use industrial Ethernet switches to connect devices.

Switch failures may cause intermittent communication problems.

Possible switch issues include:

• power supply instability
• overheating
• firmware faults.

Technicians should verify switch status indicators and power connections.

Network Traffic Overload

Industrial networks may become overloaded if too many devices communicate simultaneously.

Excessive network traffic can cause delays or packet loss.

Possible causes include:

• excessive diagnostic data
• improperly configured network polling rates
• unnecessary network devices.

Engineers should review network configuration if communication becomes unstable.

IP Address Conflicts

Each device on the network must have a unique IP address.

If two devices share the same address, communication conflicts occur.

Symptoms may include:

• intermittent connection loss
• devices appearing and disappearing from the network.

Technicians should verify IP address configuration for all devices.

Grounding and Shielding Problems

Poor grounding is another cause of communication instability.

Ground loops or improper shielding may introduce electrical noise into communication lines.

Best practices include:

• grounding cable shields at one end
• avoiding ground loops
• ensuring proper cabinet grounding.

Correct grounding significantly improves signal integrity.

PLC Communication Timeout Settings

PLC programs often include communication timeout parameters.

If a device fails to respond within the allowed time, the PLC may trigger a communication fault.

If timeouts are configured too aggressively, temporary delays may cause unnecessary faults.

Engineers should verify communication timeout settings.

Device Firmware Compatibility

Communication errors may also occur due to firmware incompatibility between devices.

Examples include:

• PLC firmware updated but drive firmware outdated
• network switch firmware incompatibility.

Keeping firmware versions compatible improves network stability.

Troubleshooting Procedure

Technicians should follow a structured troubleshooting approach.

Step 1 — Observe Fault Messages

Identify which device is reporting communication loss.

Step 2 — Inspect Network Cables

Check cables for damage or loose connectors.

Step 3 — Verify Network Switch Operation

Confirm switch power and indicator lights.

Step 4 — Check IP Address Configuration

Ensure all devices use unique IP addresses.

Step 5 — Inspect Cable Routing

Ensure network cables are separated from high-power wiring.

Network Monitoring Tools

Advanced troubleshooting may involve network diagnostic tools.

Engineers may monitor:

• packet loss
• communication delays
• device response times.

These tools help identify unstable network segments.

Preventative Maintenance for Industrial Networks

Routine inspection helps prevent network faults.

Recommended practices include:

• checking cable integrity
• tightening connectors
• verifying switch cooling
• reviewing network configuration.

Regular maintenance improves long-term reliability.

Production Impact of Network Faults

Network instability can severely affect roll forming production.

Possible consequences include:

• unexpected machine stops
• servo drive shutdowns
• incorrect machine sequences
• reduced production efficiency.

Stable communication networks are essential for reliable automation.

Benefits of Reliable Industrial Networks

Properly designed and maintained networks provide several advantages.

These include:

• reliable machine control
• fast communication between devices
• reduced downtime
• improved diagnostic capabilities.

For modern roll forming machines with multiple automation devices, stable networks are essential.

FAQ — Network Communication Problems

Why do my drives randomly disconnect from the PLC?

This may occur due to damaged Ethernet cables, loose connectors, or electrical interference.

Can electrical noise cause network drops?

Yes. VFD drives and power cables can generate interference that disrupts communication signals.

How can Ethernet cable damage cause intermittent faults?

Minor cable damage may cause occasional signal loss, resulting in communication interruptions.

Why is shielding important for industrial Ethernet cables?

Shielding protects network signals from electromagnetic interference.

What causes IP address conflicts?

Two devices accidentally configured with the same IP address will cause network communication problems.

How can engineers prevent network drops?

Proper cable routing, industrial-grade components, and regular maintenance help ensure stable network communication.