Q: What is an IODD?

IODD is the abbreviation for IO -Link D evice D escription. An IODD is a group of data files containing information about the sensors and actuators within an IO-Lin ecosystem. It stores a device's communication properties, identity, process and diagnostic data, parameters, and user interface design. Each devcie has it's own IODD and it is required to integrate the sensor into the IO-Link infrastructure. ifm provides the IODD file for each IO-Link product on its website in the Download area and on the datasheet page for each product. The IODD for each IO-Link device sold by ifm is saved in the company's parameter setting software and in other software solutions for IO-Link device and port configuration tools from ifm. The IO-Link community offers a manufacturer-independent IODD library in the IODD finder .

Question 1

What is IO-Link?

Accepted Answer

IO-Link is an open, standardized technology that allows the user to set up a point-to-point connection. IO-Link requires no sensor addressing. IO-Link components from companies that are members of the IO-Link consortium are compatible with each other.

Question 2

Is IO-Link a fieldbus?

Accepted Answer

IO-Link is not a fieldbus. IO-Link masters connect the sensors to the fieldbus and controller.

Question 3

How can I integrate IO-Link sensors into my controls system?

Accepted Answer

Users can integrate IO-Link sensors into a control system by transmitting process data from the senosr to the PLC. The PLC can read the data without further conversion. Refer to Setup and support for more information.

Question 4

What is an IODD?

Accepted Answer

IODD is the abbreviation for IO-Link Device Description. An IODD is a group of data files containing information about the sensors and actuators within an IO-Lin ecosystem. It stores a device's communication properties, identity, process and diagnostic data, parameters, and user interface design. Each devcie has it's own IODD and it is required to integrate the sensor into the IO-Link infrastructure.

ifm provides the IODD file for each IO-Link product on its website in the Download area and on the datasheet page for each product. The IODD for each IO-Link device sold by ifm is saved in the company's parameter setting software and in other software solutions for IO-Link device and port configuration tools from ifm.

The IO-Link community offers a manufacturer-independent IODD library in the IODD finder.

Question 5

How do IO-Link sensors transmit measured values?

Accepted Answer

IO-Link sensors transmit measured values in purely digital form via IO-Link communication from the sensor to PLC or cloud solution.

Question 6

How does the IO-Link measured value differ from an analog signal (4…20 mA)?

Accepted Answer

An IO-Link measured value is purely digital and requires no conversion. Analog signal transmissions convert digitally measured values in the sensor into analog signals when transmitted to the PLC (D/A conversion). There, it is converted back into a digital signal (A/D conversion). This transmission principle is prone to errors and conversion losses.

Question 7

Can wire break be detected with IO-Link?

Accepted Answer

An IO-Link master will detect a wire break while checking all IO-Link devices within a communication cycle. If a device does not respond, the master signals the break regardless of the measured value.

Question 8

Can IO-Link sensors alert to malfunctions?

Accepted Answer

IO-Link sensors can alert malfunctions and incorrect operating status by setting events in the IO-Link master's interface. The master transmits the event as a classic error code to the controller.

Question 9

What is an IO-Link master?

Accepted Answer

The IO-Link master is the device that establishes the connection between one or several IO-Link devices and the fieldbus system serving as a gateway. Refer to the product overview for more details.

Question 10

How do I configure the master?

Accepted Answer

Every master port must be configured by the user according to the requirements of the user's application: master port mode (DI, DO, IO-Link), process data width and data length. Refer to Setup and support for more information and setup videos.

Question 11

Can I benefit from IO-Link sensors without existing an IO-Link structure?

Accepted Answer

Users can benefit from IO-Link sensors without an existing IO-Link infrastructure, but they cannot utilize all features this way. Sensors perform as usual without sending additional information. Parameter setting is more difficult and replacing the sensor is more complicated without the use of the memory plug, E30398. The memory plug reads and saves an IO-Link sensor's configuration data, so parameter transfer occurs automatically.

Question 12

Can I distribute power to multiple IO-Link masters drawing more than 4A without using separate home run cables?

Accepted Answer

Yes, IO-Link masters can be connected in a daisy-chain configuration using flat cable. The flat cable is rated for up to 10A and can connect to IO-Link masters via flat cable to M12 adapters (#5 in the picture below).

DataLine IO-Link masters
M12 / RJ45 Ethernet patchcords
M12 / M12 Ethernet patchcords
Flat cable
Flat cable to M12 adapters
M12 sensor patchcords
24 VDC power supplies
Optional accessories

Frequently asked questions reqgarding IO-Link