In complex industrial systems where I/O components are spread across large machines, selecting the appropriate sensor cable layout strategies is essential for cost-effective wiring, minimizing downtime, and achieving optimal performance in challenging industrial environments. In large-scale systems, like long conveyor lines, large machines, or even a complex production line, the centralized wiring method quickly becomes inefficient. We have a special passion for cables with high flexibility which suit the requirements of these new distributed architectures; for fieldbus solutions and for industrial Ethernet cables that enable these new architectures to function and ensure long term reliability and clean installs for the engineer.
In this guide we will look at some practical layout ideas from real-world use, including the best ways to group sensors, make use of local I/O nodes, choose the right cable and compromise on the reduction and maintainability of cable.
From Centralized Panel Wiring to Distributed I/O – What Changes for Sensor Cabling?
In the past, all of the sensor and actuator cable runs from large machines have been made to a central control cabinet. This is suitable for smaller systems, but presents problems as the number of machines and I/Os increases.
Traditional Centralized Wiring – Every Sensor Back to the Cabinet
With a centralized design, every sensor must have a long cable with trays, conduits or drag chains to the main panel. This leads to large cable bundles in a 100-meter conveyor or a large robotic assembly line, higher material costs, more labor in installation, and higher potential for electromagnetic interference or mechanical failure. It can take a long time to diagnose and fix a single failing sensor, causing longer downtime.
Distributed and Remote I/O – Short Local Runs + Network Cable
The paradigm is changing with distributed I/O; I/O modules are located close to clusters of sensors and actuators. Sensors are linked to each other by short cables, and the module communicates back to the main controller over a single fieldbus or Ethernet cable. This significantly decreases the overall cable length, complexity of the harness, weight and enhances signal integrity and diagnosis.
Core Layout Principle – Group Sensors by Subsystem and Use Local I/O Nodes
The first step to designing sensor cable layout is to consider the approach from the subsystem perspective instead of device-by-device perspective.
Place I/O Modules Near Subsystems
Locate natural machine zones (e.g. hydraulic, conveyor, robotic arm or material handling areas) and place remote I/O modules near them. This enables local connections to be made using short sensor and actuator cables (typically 1-5m), and only the network backbone to cover the full length of the machine.
Replace Long Point-to-Point Runs with Local Connections
Local machine side routes can be achieved with multi-core sensor/actuator cables, which bundle power, signals and feedback into a single, sturdy cable. Hulk’s high flexible designs are outstanding for moving sections, providing excellent torsion and bending.
Use Multi-Core Sensor/Actuator Cables for Machine-Side Routes
Design cables that are suitable for movement, abrasion and environment according to their conductor sizes, shielding and jackets (e.g. PUR for oil resistance and flexibility). This helps to keep the signal quality good when routing in drag chains or trays in a clean manner.
Choosing Fieldbus and I/O Components with Cable Reduction in Mind
The choice of components impacts directly the efficiency of the layout.
Fieldbus Topologies that Minimize Cabling
Use flexible fieldbus such as PROFINET, EtherCAT and DeviceNet with daisy chain or ring structure. These will minimize the need for individual home runs and allow diagnostics. Industrial Ethernet and fieldbus cables from Hulk are designed for these networks, available in CAT5e to CAT7A with high level of shielding.
One-Cable Technology and Pluggable I/O Terminals
Use hybrid cables (power and data) as much as possible or prefabricated assemblies with application-specific connectors. This makes it easier to install and decreases the number of connections.
Daisy Chains vs Rings vs Stars
Daisy chains save on cable usage but there needs to be some planning in order to isolate faults. Redundancy for critical applications is added in ring topologies. Compare the size of the machines, maintenance access and uptime.
Machine-Side Sensor Cable Layout – Trays, Carriers and Separation
Physical routing remains essential even with distributed architectures.
Cable Trays, Harness Paths and Drag Chains
Design special routes around moving axes and machine frames. High-flex cables from Hulk are capable of millions of cycles in drag chains, for continuous operation in robotics and automation.
Route Separation and Connector Choices
Keep signal away from the power lines to prevent interference. Ensure that any motors and drives are connected to shielded sensor cables with reliable, IP-rated connectors in washdown or dusty areas.
Distribution Blocks and Enclosure-less I/O in Layout Strategies
Passive and Active Distribution Blocks Near Sensor Clusters
Distribution blocks are suited to areas with a high concentration of sensors as they are used to group a number of short cordsets into one cable that feeds into the area. This reduces the amount of cabling and simplifies maintenance.
Enclosure-less I/O Strategies
The no-enclosure solutions are the modern solution, offering IP-rated protection without the need for big boxes, further simplifying layouts on large machines.
Distributed vs Centralized Architectures – When Layout Strategies Change
If the number of I/O points is 150-200 or less, centralized wiring can be used. Beyond those benefits—particularly on a large, physical piece of equipment—distributed I/O often provides for lower total ownership costs, as well, due to the fact that less wiring is required, often 30-50%, and it troubleshoots much faster. .
Practical Sensor Cable Layout Patterns for Large Machines
- Construction Machinery (e.g., Excavator Boom): Local use of short high-flex sensor cables and a single CAN bus or Ethernet backbone configuration.
- Long Conveyor Systems: Use distributed nodes every 20-30 meters: Connect sensors locally, link nodes via fieldbus and get simplified long distance communication.
- Efficient, modular designs: Automated Production Lines – Cluster sensors around stations and use multi-core actuator cables.
Design Checklist – Sensor Cable Layout for Large Machines with Distributed I/O
- Consider short runs of high-flex multi-core sensor/actuator cables.
- Choose fieldbus networks that achieve an optimum compromise between efficiency and fault tolerance.
- Define cable jackets, shielding and bend radius for environment.
- Record routes and get diagnostic-ready components for quick maintenance.
When applying these sensor cable layout strategies, large machines can have better modularity, lower costs and higher reliability. Our sensor & actuator cables, robot torsion cables, industrial Ethernet and fieldbus cable solutions are designed for just these applications, and have been tested with stringent validation and certified worldwide, with a wealth of customisation experience.
Let us know what type of machines you have and we’ll suggest the best cable options for your distributed I/O configuration.