IO‐Link system overview
IO-Link is the first standardized IO
technology worldwide (IEC 61131-9) for the communication with sensors
and also actuators. The powerful point-to-point communication is based
on the long established 3-wire sensor and actuator connection without
additional requirements regarding the cable material.The system architecture may be as follows:
Figure 1: System architecture example
An IO‐Link master can have one or several ports. Only one IO‐Link device can be connected to each port. Thus IO‐Link is point‐to‐point communication and not a field-bus.
What is IO‐Link
Pin Configuration
These 3 pins are used for the IO-Link communication as well as for supplying a maximum of 200 mA to the device.
IO-Link is Easy
- Simple Installation Reduction and standardization of wiring - unscreened M12 connection technology is sufficient.
- Automatic parameter settingCentralized creation, storage and retrieval of device parameters - also during operation.
- Extended diagnosisQualitative system and process diagnosis from the sensor / actuator level to the control level. Analogue value transmission without loss up to 20 m.
IO-Link Advantages
1. Standardized and Reduced Wiring
A
critical benefit of IO-Link for many industries is that IO-Link does not
require any special or complicated wiring. Rather, IO-Link devices can be
connected using the same cost-effective standard unshielded 3-wire cables as
conventional discrete I/O which helps keep wiring simple. In addition,
IO-Link also eliminates the need for analog sensors and reduces the variety of
cord sets required for sensors, which saves inventory costs. IO-Link also
supports a master-slave configuration with passive connection points, which
further reduces wiring requirements.
2. Increased Data Availability
Data
availability is a powerful advantage of IO-Link that has far-reaching
implications. Access to sensor-level data helps ensure the smooth
operation of system components, streamlines device replacement, and enables
optimized machine maintenance schedules all of which save costs and reduce the
risk of machine downtime.
There are
three primary data types made available via IO-Link communication, which are
categorized as either cyclic data (data automatically transmitted on a regular
basis) or acyclic data (data transmitted as needed or upon request).
- Process Data refers to the information that the device reads and transmits to the master such as the distance reading on a laser measurement sensor. Process data can also refer to information that is transmitted to the device from the master (such as messages sent to a tower light indicating which color segments should be illuminated). Process data is transmitted cyclically in a defined data frame. In addition, value status data indications of whether or not process data is valid is transmitted along with process data.
- Service Data—also called Device Data—refers to information about the sensor itself such as parameter values, model and serial numbers, device descriptions, etc. Service data can be both written to the device or read from the device acyclically.
- Event Data refers to notifications such as error messages or maintenance warnings (e.g. device overheating, dirty lens) that are transmitted acyclically from the IO-Link device to the master whenever an event occurs.
This
wealth of valuable data made available through IO-Link is integral for the Industrial Internet of
Things (IIoT) and Industry 4.0 initiatives.
3. Remote Configuration and Monitoring
With
IO-Link, users can read and change device parameters through the control system
software, enabling fast configuration and commissioning that saves time and
resources. In addition, IO-Link allows operators to dynamically change
the sensor parameters from the control system as needed such as in the case of
product changeover which reduces downtime and allows machines to accommodate
greater product diversity. This is especially important in consumer
packaged goods applications where the demand for variety in packaging is
continually increasing.
In
addition, the ability to monitor sensor outputs, receive real-time status
alerts, and adjust settings from virtually anywhere allows users to identify
and resolve problems that arise on the sensor level in a timely manner.
This also means that users can make decisions based on real-time data from the
machine components themselves, which can reduce costly downtime and improve
overall efficiencies.
4. Simple Device Replacement
In
addition to the ability to remotely adjust sensor settings, IO-Link’s data
storage capability also allows for automated parameter reassignment in case of
device replacement (this functionality is also known as Auto-Device Replacement
or ADR). Users can import existing sensor parameter values into a
replacement sensor for seamless replacement, getting the new device up and
running as quickly as possible.
5. Extended Diagnostics
IO-Link
provides users with visibility into errors and health status from each device.
This means that users can see not only what the sensor is doing but also how well
it is performing a valuable insight into a machine’s efficiency. In
addition, extended diagnostics allow users to easily identify when a sensor is
malfunctioning and diagnose the problem without shutting down the line or
machine.
The combination of both real-time and historic
data made available via an IO-Link system not only reduces troubleshooting
efforts as issues arise but also allows for optimization of machine maintenance
schedules, saving costs and increasing efficiency in the long term.
Allen Bradley Controllogix PLC connect to IO-Link EtherNet Master Tutorial Blog Click Here
Allen Bradley Controllogix PLC connect to IO-Link EtherNet Master Tutorial Blog Click Here
