Advantages of Single-Pair Ethernet and IO-Link

28 November 2023

Welcome to the first in a series of blogs on digital transformation in the life sciences industry. Thanks to ever-evolving technologies, managing data is faster, easier to automate, and more accurate than ever.  We’ll kick this series off with an overview as to how using single-pair Ethernet (SPE) and IO-Link is fueling change in life sciences manufacturing facilities.

What is SPE?

Single-pair Ethernet, or SPE, is a new physical network standard used for factory, process, and building automation, available at speeds up to 1 Gbps. SPE differs from standard industrial Ethernet; instead of using four to eight total wires, it uses only two wires that twist together to create one cable providing communication across industrial Ethernet protocols. This allows for data transfer at the lowest automation level. It also offers full transparency from sensors and actuators to the cloud.

Traditionally, sensors and controls use specialized networks for support. Upgrading these systems to SPE simplifies cabling and management. It could potentially eliminate purpose-made networking equipment such as gateways and linking devices. Using SPE also allows standard network security and existing communication protocols, such as Ethernet/IP and Profinet®.

SPE can also deliver a simultaneous power supply to end devices using a Power over Data Line (PoDL). Special cables and connectors allow power and data to be transmitted over a single cable. Various cable configurations and power capacities can deliver up to 16A to connected devices.

Another benefit to using SPE is that, in conjunction with advances in safety technology for communication networks, it provides an opportunity to extend Ethernet to hazardous plant areas without placing additional burdens on automation engineers. This means a single network strategy can be employed from the field to the cloud by changing only the physical installation details to match the process environment.

Applied to life sciences facilities, the simplicity of SPE can significantly reduce the installation footprint, including the need for conduits in clean spaces. SPE networks can be installed in a multi-drop configuration, eliminating most cable home runs, and allowing for much simpler and smaller I/O cabinets.

All these facets of using SPE combine to reduce wiring costs, node costs, and power consumption while enabling faster data communication and a more robust Internet of Things (IoT) network.

What is IO-Link?

IO-Link is an industrial communications protocol that connects smart sensors and actuators to higher-level controllers, such as programmable logic controllers (PLCs) and edge controllers. As a modern communication standard for connecting digital devices to controllers in industrial applications, IO-Link is typically used to monitor, manage, and control sensors in the field. This protocol works over an unshielded three-wire cable and features speeds up to 321KBps over no more than 20 meters using M5, M8, and M12 connectors.

IO-Link provides fast access to a rich set of digital data from the device according to the manufacturer’s design, including device performance and advanced diagnostic data.  It performs very well in a digital environment because it is bi-directional and point-to-point.

Based on an established three-wire sensor and actuator connection, IO-Link is popular in Europe but relatively new to the US market. However, it has growing acceptance in the US due to its ease of connectivity for end users, system integrators, and original equipment manufacturers (OEM).

What is the advantage of using SPE with IO-Link for life sciences manufacturing facilities?

SPE supports a wide range of speeds within its single connector and is an ideal upgrade to a system using IO-Link.

Using a standard cable to connect an IO-Link master port and an IO-Link device allows for 20 meters between the port and the device. Also, remember that longer cables and repeaters add latency to the IO-Link data transfer, necessitating a slowdown of the IO-Link’s master port cycle time due to the delay. This is the biggest downside to using IO-Link in high-speed applications.

SPE, however, can allow your IO-Link cabling to extend to 100 meters – five times the distance you could have previously achieved! IO-Link master field modules with an Ethernet port allows the data collected via IO-Link from up to 8 connected devices to be shared directly on the Ethernet network.   You still use the same IO-Link, but the delivery method has changed. All defined interfaces and functions are retained.

Using SPE in conjunction with IO-Link can help provide enhanced field-level data and diagnostics that will allow for deep data analysis used to monitor batch operations, improve process performance, and assist in preventative maintenance.

Experts have been discussing the advantages of replacing some facility Ethernet networks with SPE for some time. I feel there is more interest and popularity even though only a few devices are available with SPE capability. This trend will likely snowball as more life sciences organizations make the change and start seeing improvements in speed and accuracy.

I believe, over time, the advantages of SPE, including the wealth of device-level data that can be obtained, will rapidly increase the number of SPE nodes in life sciences manufacturing.  SPE is following a similar adoption curve as with RFID and instrument communication technologies, indicating sizable market penetration within the next 3-5 years.