IO-Link sensors and measuring electronics

IO-Link sensors and measuring electronics for force and weighing bring readings digitally from the sensor into the control system, via an unshielded standard cable and M12 connector, without an analog card and independently of the fieldbus above. You will find strain gauge amplifiers here as well as force transducers and load cells with directly integrated IO-Link electronics.

What IO-Link is

IO-Link is a vendor-independent, standardized point-to-point connection between a sensor or actuator and an IO-Link master, defined in IEC 61131-9. The master sits in the control cabinet or as a field module in the plant and is in turn connected to the fieldbus.

The decisive point: IO-Link is fieldbus-independent. Whether PROFINET, EtherCAT or another protocol runs above the master makes no difference to the sensor. You can use the same sensor type in plants with different control architectures, which considerably simplifies spare parts management and standardization in machine building. We explain the basics and the setup in detail on our page on IO-Link.

The connection itself runs over an unshielded three-wire standard cable with an M12 connector, usually up to 20 m. No shielded measuring cables, no special routing rules, no analog input card.

Three channels in one cable: IO-Link sensors and measuring electronics

Unlike an analog signal, IO-Link transmits not just one value but three types of information:

Process data is transmitted cyclically: the actual measured value and the associated status bits.

Parameter and service data is exchanged acyclically when needed. This is how you set the measuring range, zero point, filter and limit values – from the engineering tool rather than on the device.

Events are reported by the device on its own, such as a wire break, a sensor fault or a limit value being exceeded. An analog signal cannot do this; all you are left with there is an implausible value that the control system has to interpret.

What this changes in operation

Wiring. A single standard sensor cable type for all devices instead of shielded measuring cables, analog lines and separate power supplies. This reduces sources of error during installation and the effort for documentation.

Parameterization. Settings no longer live in the device but in the project. They are documented, reproducible and can be rolled out identically for an entire machine series.

Device replacement without rework. This is the advantage you only learn to appreciate when service is needed. The master stores the parameters and automatically loads them into the replacement device. Changing a sensor thus becomes a mechanical task that maintenance staff can carry out without any knowledge of measurement technology. With analog evaluation, the system would instead have to be rescaled or recalibrated with test weights.

Diagnostics and statistics. Depending on the device, IO-Link also supplies minimum, maximum, peak value, an operating hours counter or a load spectrum. This lets you assess whether a press or a hoist is operated within its design limits, and a brief overload remains visible that would long since have disappeared from the cyclic process value.

What we offer with IO-Link

Strain gauge amplifiers. A compact module close to the sensor turns any existing strain gauge full bridge into an IO-Link device. The route for retrofits and for applications where the sensor type is fixed.

Force transducers and load cells with integrated electronics. Here the amplifier sits in the sensor housing; there is only one device and one cable. More compact and more robust, the better choice for new designs. Our load cells and force transducers can be equipped with IO-Link in this way.

Custom sensors with IO-Link. If no standard design fits, we develop the transducer to your specifications and integrate the interface at the same time. Design, manufacturing, strain gauge installation and electronics are all done in-house.

Commissioning

Every device comes with an IODD file, the standardized device description. You load it into your engineering tool, after which all parameters and process data are available with names and units. You set scaling, zero point and filter there, not on the device. No opening of housings, no potentiometers, no DIP switches.

The IODD file, data sheet and CAD model are available for download with every item.

When IO-Link is the right choice, and when it is not

In favor: several measuring points on one machine, high requirements for reproducibility and documentation, series machine building, plants with frequent sensor replacement, a need for diagnostic and condition data, and any situation where no analog card is free.

Against: fast dynamic measurements, because IO-Link transmits cyclically in the millisecond range. For a force curve during impact or joining processes, use a strain gauge amplifier with the corresponding bandwidth. Long distances, because IO-Link is a point-to-point connection with a limited cable length; for the route from the silo to the control room, a weight transmitter with a bus or analog output is more suitable. And a single weighing point without an existing master, because the infrastructure then does not pay off.

IO-Link is not intended for legal-for-trade use; there, weighing indicators with the corresponding approval are the way to go.

Matching components

Further evaluation electronics can be found under measuring electronics, and information on fieldbuses on our fieldbus page. So that you measure in newtons or kilograms rather than in mV/V, we calibrate the measuring chain to ISO 17025 in our own laboratory on request.

Our engineers will advise you directly on choosing the sensor, interface and scaling.