Designed for simplicity and universality, the communications protocol IO-Link isn’t the latest thing, but there are plenty of factories that are missing out on what it offers.
There is sometimes a little confusion about IO-Link – the first global standard for communicating with sensors and actuators.
To begin with, it is not a proprietary solution, which is the first thing that needs clearing up, believes Freddie Coertze, Field Technical Support Engineer, Networks and Controls at ifm efector Australia.
“It’s a nice thing to actually buy into from a customer point of view; the main reason is you’re not locked into one supplier,” Coertze told Manufacturers’ Monthly.
“So you can use different manufacturers’ IO modules, sensors, whatever, as long as they’ve got IO-Link in it.”
Secondly, though the buzzword Industry 4.0 might call up something futuristic in your imagination, IO-Link – one of the essential connectivity solutions required for this – is very much here and now. In fact the Company Coertze works, ifm efector, for has been making IO-Link-enabled sensors for almost a decade.
IO-Link can help users get much more data out of their sensors and unlock some of the “trapped data” currently held prisoner in the sensor.
“We can basically link a sensor up to your SAP [a major ERP software provider] interface. To be able to do that is a benefit, because let’s say your sensor is starting to fail,” explained Coertze.
“As an example, let’s use an IO-Link-enabled pressure sensor. It’s working all good, giving my pressure values, everything is fine, but if that pressure valve becomes invalid I can get a message from my sensor saying I am no longer healthy.” This is achievable via the sensor’s error messages monitored by the IO-Link master and passed up to the PLC or Controller.
In such a case, a diagnosis can be made via information sent through the sensor – which may have failed due to overheating – via the PLC to the enterprise system. A job ticket is produced and a floor worker can change the failed device.
Further to this, a network using IO-Link does not have to be shut down in its entirety and a production line or machine can keep running, provided it is safe to do so.
Right from installation, in fact, an IO-Link-enabled sensor can begin displaying its usefulness. It can display three types of data, the first of these being service data: data about the device itself, including part number and manufacturer details.
The other two types of data are event data (such as notifications and flags, for example in the failed pressure sensor example) and process data (whatever the sensor is supposed to be reading).
Crucial data can be accessed remotely – very much essential in any Industry 4.0 cyber-physical representation of a factory and its workings.
“You can basically see all of your sensor parameters in there. You can see – even with a simple pressure switch – for instance – not just an on/off signal,” said Coertze.
“And that means if I connect it to an IO-Link input I enable more out of my sensors. I can basically get a floating value and my resolution is much higher because if I wanted to create an analog, I’ve got to scale it between 4 and 20 milliamps. Where now I can have the real value.”
The simplicity of IO-Link was being enthusiastically embraced by younger engineers, he added.
“New engineers moving into the field, you can see they are more adapted to technology and can really see the benefit of this,” he said, continuing “if you can basically screw an M12 connector on a sensor, you can basically do IO-Link – it’s really not that difficult.”
The benefits of the newer types of data made available can save money, and apply to even the most traditional of manufacturers.
One example is in energy monitoring, a purpose which Coertze’s company covers (along with condition monitoring) through its partnership with SAP and its cloud platform.
“For example, in most manufacturing environments you need to have compressed air. So let’s say I’ve got leaks in my compressed air lines which I never knew about, that means my compressors will be running inefficiently 24/7,” he said.
“So we want to use that sort of SAP environment to collect data… Our sensors can collect data for us and that means I can measure the input of all my airlines and I can see on the end that I’m losing all my air.
“And that means I can collect all of my data into a Historian, I can transfer the data into SAP, and draw a report.
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