Siemens Industry Online Support
Siemens AG
Entry type: Application example Entry ID: 80198907, Entry date: 10/24/2013

High-precision Gap Measurement with an Advanced Light Barrier via ET 200eco PN IO Link Master

  • Entry
  • Associated product(s)

An innovative development of the sensors and the use of the open standard IO Link ensures a consistency from the sensor level to the control level, which is much easier to achieve as compared to former times and offers new possibilities. This application demonstrates these possibilities with a typical example from production technology and the resulting advantages for the user.

The concrete task to be solved here is a high-precision measurement of the gap between two products on a moving conveyor belt:

The conventional solution of determining the time between two products with timers in a controller is not practical for a high-precision gap measurement.

The high-precision gap measurement is carried out by means of innovative features in a SICK sensor (Advanced functions). The sensor internally detects the time between two passing products.

The evaluation and decision whether the gap is sufficient, is done by a SIMATIC controller which compares the actual value with the target value. What is decisive for the use of the data consistency from the sensor level to the control level is the open standard IO link. The following figure shows the setup for this solution:

Therefore, this Application Examples basically deals with

  • a sensor, which enables a high-precision gap measurement in the first place by means of the Advanced functions (such as the internal time measurement).
  • a powerful controller, which can read but also write configuration data into the sensor.
  • the function principle of IO Link.

The focus being on the interaction of sensor and controller via IO Link. In order to address readers who are not completely familiar with the above aspects, the latter are discussed in a separate chapter on the basics.

The application on hand offers the following advantages:

  • Possibility of a high-precision gap measurement on the basis of the data consistency from the sensor to the control level by means of IO Link.
  • Simple start-up including step-by-step instructions.
  • Comfortable operation and visualization by SIMATIC HMI.
  • Configuration of the sensor can be done over the HMI.
  • High productivity, since data are pre-processed in the sensor due to its Advances functions, which increases the throughput and thus the productivity.
  • Quick adaptation to changed tasks (Example: Instead of measuring the gap between two products, you wish to determine the length of the product).


Contents of Download


Documentation 80198907_Gap_measurement_v10_en.pdf ( 1234 KB )
(STEP 7-Projekt V5.5)
80198907_Gap_measurement_v10.zip ( 4497 KB )

Security Notice
The functions and solutions described in this article confine themselves to the realization of the automation task predominantly. Please also take into account that corresponding protective measures have to be taken up in the context of Industrial Security when connecting your equipment to other parts of the plant, the enterprise network or the Internet. Further information can be found under the Entry ID 50203404.

Additional Keywords
S7-300, S7-400, sensors, sensor technology, single items, piece goods

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit
Support to the statistics
With this function the IDs found are listed according to number (format .txt).

Generate list
Copy URL
Display page in new design
mySupport Cockpit
Related links