IO-Link: The standard for networked factories

Compartment occupation check and push-through protection

Requirement:

Before a pallet or a container is stored in a rack, it must be ensured that the rack is empty. As the telescopic arm or fork moves in, it needs to be ensured that the stored goods are not pushed in the wrong direction.

Solution:

The diffuse sensors of the HT 10, 110 and ODT 25C series also detect a wide range of pallets and containers. With their precise switching points, they can be used on nearly every stacker crane for compartment occupation checks or for push-through protection.

Advantages of IO-Link:

• Should an exchange be necessary, stored parameters of the previous device are taken over
• Improved diagnostic options via remote maintenance
• Remotely adjustable switching points

Material thickness measurement

Requirement:
To ensure an optimum punching process, the material thickness must be checked. This is performed by measuring the distance to the material with high resolution.

Solution:
The ODS 9 sensor measures distance with resolutions down to 0.01 mm, thereby providing the precision needed to ensure high quality at this stage of the process.

Advantages of IO-Link:

• High process transparency by signaling relevant diagnosis events
• Automatic configuration by means of IO-Link master or function module
• Process data – such as the material thickness of the sheet metal plate – is available in real time
• Measurement data is digitally transferred and processed loss-free

Sag/loop control

Requirement:
If, during clocked processes, raw material is fed in from coils, loop control must be performed to compensate for feed fluctuations. This means the material tension must be monitored. Feeding in material at the right time helps prevent breakage.

Solution:
The tension of the material can be monitored by measuring the sag. Due to their various light-spot shapes, the ODS 10 and ODS 96 sensors can reliably measure the sag of a wide range of different material surfaces.

Advantages of IO-Link:

• High process transparency by signaling relevant diagnosis events and measurement data in real-time
• Automatic configuration by means of IO-Link master or function module
• Optimizations using the controller or by the machine operator during the ongoing process are possible

Parts detection and type testing

Requirement:
In an automotive body shop, structure parts and different variants must be reliably detected and inspected. The inspection takes place directly during the production process. This may require installing the sensors outside the robots’ working areas.

Solution:

The ODT3C and ODT25C distance sensors are ideal for reliable parts detection. Their compact design and operating ranges of up to 2 m and 3 m respectively allow for easy integration even in confined installation spaces. The integrated distance measurement ensures reliable detection of components and their position in the process.  

For inspecting different component variants, the measuring and switching TOF sensors ODS 110 and HT 110 offer a high-performance solution. Thanks to their compact design, they can be flexibly integrated even in constrained spaces. For monitoring longer distances, the ODS 10 and HT 10 sensors are suitable, with operating ranges exceeding 5 m. This allows the sensors to be mounted outside robot cells if necessary.

Advantages of IO-Link:

• Automatic adjustment of measurement ranges and switching points when changing models or variants via PLC parameterization 
• Real-time availability of measurement values and process data for continuous process monitoring 
• Optimizations and adjustments during ongoing operation without system downtime 
• Convenient remote setting and fine-tuning of switching points 
• Increased flexibility when switching products with a wide range of variants 
• Improved transparency and diagnostic capabilities for higher system availability 

Detection of transparent objects

Requirement:
Transparent objects on a conveyor belt must be reliably detected during the ongoing process – even in cases of challenging environmental conditions such as fogging, water vapor or soiling.

Solution:
Through the use of a retro-reflective photoelectric sensor for transparent objects with IO-Link – such as our PRK 3C, PRK 55C or PRK 18B – environmental influences can be detected and analyzed so that the machine control can respond.

Advantages of IO-Link:

• Output of the process data in real-time by means of dual channel:
• Channel 1: Fast trigger signal via the switching output
• Channel 2: Configuration and monitoring via IO-Link
• Output of the actual values and of the switching thresholds for online process diagnosis

Measurement of roll diameter

Requirement:
The diameter of a material roll is to be configured to control the tensile force and unrolling speed of the machine and to detect the time remaining before a roll needs to be changed.

Solution:
An optical or ultrasonic distance sensor – such as ODS 9 or ODS 96B – measures the distance from the sensor to the roll. The measurement values are digitally transmitted to the machine control via the IO-Link process data. No conversion of measurement values from analog to digital is necessary.

Advantages of IO-Link:

• Digital transmission of the distance values
• Switching thresholds can be used by the machine control depending on the material and surface
• Simple and fast possibility of diagnosis

Detection of print marks

Requirement:
With the help of a contrast sensor, print marks on a product need to be detected. The print marks and backgrounds may vary from product to product.

Solution:
An optical contrast sensor – such as the KRT 3C or KRT 18B – is used to determine the optimal contrast ratios based on several transmitter colors. The transmitter colors are taught in once using a teach routine and stored in the sensor or control. IO-Link can then be used to select defined and taught products from the recipe memory of the sensor or transfer them from the control. No new teach-in process is necessary.

Advantages of IO-Link:

• When changing products, recipe presets are retrieved from memory
• Output of the current actual values of the contrast ratios and evaluation in the machine control
• Output of the process data in real-time by means of dual channel:
• Channel 1: Fast trigger signal via the switching output
• Channel 2: Configuration and monitoring via IO-Link

Detection of objects in film

Requirement:
Objects that lie between two film webs must be detected and their width measured.

Solution:
The type CML 730 measuring light curtain with power setting transilluminates the partially transparent films with its transmitter that has been set to high power. The number and position of the interrupted beams is output to the machine control via the IO-Link interface. Preset, material-dependent beam parameters can be output to the light curtain via IO-Link.

Advantages of IO-Link:

• Fast output of all beam data
• Presets can be configured via recipe management
• Simple diagnostic options