Rockwell Automation Implementation

ControlNet for Rockwell Automation

Deterministic network protocol for real-time control applications. Part of CIP family (Allen-Bradley/Rockwell).

Type: FieldbusSpeed: 5 MbpsReleased: 1997Organization: ODVA

5 Mbps

Bandwidth

Max Nodes

1000m (coax), 3000m (fiber)

Max Distance

Yes

Real-Time

Protocol Overview

Deterministic network protocol for real-time control applications. Part of CIP family (Allen-Bradley/Rockwell).

When to Use ControlNet

Choose ControlNet for existing installations or when upgrading legacy systems. For new projects, EtherNet/IP is recommended.

Technical Specifications

Physical Layer

Physical Layer: Coax or fiber optic
Cable Type: RG-6 coax or fiber optic
Topology: Bus, Star, Tree
Power Over Cable: No

Data Layer

Data Link: CTDMA (Concurrent Time Domain Multiple Access)
Encoding: Manchester
Error Detection: CRC-32
Frame Size: 510 bytes

Performance

Scan Time: 2-100ms (configurable NUT)
Deterministic: Yes
Real-Time: Yes

Certification

Certification Required: Yes
License Cost: ODVA conformance testing
Version: Current

Advantages & Disadvantages

Advantages

✓Highly deterministic
✓Repeatable performance
✓CIP family integration
✓Scheduled and unscheduled traffic
✓Good for motion control
✓Redundant media option
✓Hot-swappable taps

Disadvantages

✗Expensive hardware
✗Complex configuration
✗Being superseded by EtherNet/IP
✗Limited vendor support
✗Specialized cable/taps required
✗Lower speed than modern alternatives

Common Use Cases & Applications

High-speed assembly lines

Motion control systems

Critical manufacturing processes

Automotive paint shops

Legacy Rockwell installations

Industry Adoption

Adoption LevelLow (legacy)

Market Share<5% (legacy installations)

Geographic PresenceNorth America primarily

Primary Industries

AutomotiveDiscrete Manufacturing

Supported Message Types

Scheduled (time-critical)

Unscheduled (messaging)

Supported PLC Brands

Allen-Bradley Rockwell

Quick Links

Alternative Protocols

Related Standards

IEC 61131-3
International standard for programmable logic controller programming languages. Defines 5 programmin...
IEC 61131 Series
Complete series of international standards for programmable logic controllers covering hardware, sof...