IO-Link is a standardized communication protocol used in industrial automation to enable communication between sensors or actuators and a master device, such as a programmable logic controller (PLC) or a distributed control system (DCS). It facilitates the data exchange and configuration parameters between devices reliably and efficiently.


Rheonics has successfully implemented an IO-Link communication with their electronics for communication with IO-Link Masters. This enables online process viscometer SRV to transmit real-time viscosity and temperature measurement data over IO-Link to other devices like PLC and IO-Link master. Similarly, Rheonics process density meter SRD can transmit density, concentration, specific gravity, viscosity, kinematic viscosity, and temperature over IO-Link.



Figure 1. IO-LINK master devices

1. Components

1.1. IO-Link master

An IO-Link master is a device used in industrial automation to connect and manage communication between IO-Link-enabled sensors or actuators and a higher-level control system, such as a PLC or a PC.

1.2. IO-Link Adapter

An IO-Link converter is a device that facilitates the conversion between different communication protocols.

1.3. Rheonics SME

The SME-DRM is an ultra-fast and robust electronics combined with comprehensive computational models, suitable for mounting on DIN rails and inside cabinets. Powered by 24Volts, the Rheonics SME-DRM is equipped with an Ethernet port, SD card slot, Modbus RTU RS-485 port, and 3 channels for 4-20 mA Analog outputs.

2. Hardware connection and block diagram

Connect the IO-Link adapter from the Rheonics sensor to an IO-Link Master device.

Figure 2. Rheonics SME IO-Link slave to IO-Link Master


3. Data Structure

Address 0                

                                                                                                                                     

Parameter

Data In

Format

Sensor Status

1

Unsigned Int16

Power Supply

2

Float 32

-

3

-

Parameter 12 Viscosity Last Good

4

Float 32

-

5

-

Parameter 12 Viscosity Last Good -Status

6

Unsigned Int16

Parameter 13 Density Last Good

7

Float 32

-

8

-

Parameter 13 Density Last Good - Status

9

Unsigned Int16

Parameter 2 Temperature Median

10

Float 32

-

11

-

Parameter 2 Temperature Median -Status

12

Unsigned Int16

Parameter 4 Kinematic Viscosity

13

Float 32


14


Parameter 4 Kinematic Viscosity-Status

15

Unsigned Int16

Table 1. Address 0 data access point

4. Accessing the Data

4.1. Open PACTware and select the IO-Link device that is connected

4.2. Scan the connected device to display all preconfigured data stored in the Rheonics sensor.

4.3. In Output (from PLC), select the address 0 to access the preprogrammed data from the adapter. This will provide access to the Input registers from the sensor. Check Table 1

4.4. In Pactware to visualize data, go to “Process data”, and click the cyclic read button.


Figure 3. Starting cyclic read with Rheonics sensor


4.5. The data should be converted back into the PLC or DCS using the information from Table 1

5. How to check the data in a PLC?

Check this support article: https://support.rheonics.com/en/support/solutions/articles/81000413652-io-link-integration-with-s7-1200-with-io-link-master-sm-1278