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 the online process viscometer SRV to transmit real-time viscosity and temperature measurement data over IO-Link to other devices like a PLC and an IO-Link master. Similarly, the 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 Adapter

An IO-Link converter facilitates conversion between different communication protocols. Only white and black wires are connected to the electronics. No other wiring is needed.

1.2. 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, an SD card slot, a 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          

                                                                                                                                     

Parameter

Data In

Format

Sensor Status

1

Unsigned Int16

Parameter 0 - Viscosity Median

2

Float 32

3

Ignore

4

Ignore

Parameter 0 - Viscosity Median Status

5

Unsigned Int16

Ignore

6

Ignore

Ignore

7

Ignore

Ignore

8

Ignore

Ignore

9

Ignore

Parameter 1 - Density Median

10

Float 32

11

Ignore

12

Ignore

Parameter 1 - Density Median Status

13

Unsigned Int16

Ignore

14

Ignore

Ignore

15

Ignore

Table 1. Address 0 data access point


Parameter

Data In

Format

Parameter 2 - Temperature Median

1

Float32

2

Ignore

3

Ignore

Parameter 2 - Temperature Median Status

4

Unsigned Int16

Ignore

5

Ignore

Ignore

6

Ignore

Ignore

7

Ignore

Ignore

8

Ignore

Parameter 4 - Kinematic Viscosity

9

Float 32

10

Ignore

11

Ignore

Parameter 4 - Kinematic Viscosity Status

12

Unsigned Int16

Ignore

13

Ignore

Ignore

14

Ignore

Ignore

15

Ignore

Table 2. Address 1 data access point


                                                                                                                                     

Parameter

Data In

Format

Power Supply

1

Float 32

2

Table 3. Address 2 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 addresses 0,1, and 2 to access the preprogrammed data from the adapter. This will provide access to the Input registers from the sensor (see Tables 1, 2, and 3).

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 the tables.

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