Why are open connectivity solutions needed?
Nowadays, we want to send the data we produce to the cloud or another machine, which computes the data and visualizes the process values. For some time, specific devices have implemented many communication protocols like Modbus TCP, MQTT, or even Rest API, allowing us to send values in many solutions. Increasing digitalization allows for ensuring secure transmission, storage, and acquisition of data. Collecting and processing data increases the productivity and quality of a plant and enhances efficiency.
Modern equipment ships with a toolbox of open protocols that let a machine push its values onward — to the cloud, to another machine, or to an analytics layer.
Modbus TCP
Industrial protocol for reading process values over Ethernet.
MQTT
Lightweight publish/subscribe messaging for sending values to the cloud or other machines.
REST API
Web-standard interface modern devices expose to share data across many solutions.
Do we need to change older devices to newer ones?
In the case of older machines, it is more challenging to send data to other devices. Usually, there is not even Ethernet connectivity. Then we have to implement retrofitting of devices. There are some solutions, and we must decide which is the most suitable for our case.
Recently in #tech_hive we had a similar situation. In that case, the old device had only analog interfaces, both current and voltage. After some analysis, we decided to use Advantech ADAM-6024, which has analog and digital input and output, and Modbus TCP and MQTT.
The device was connected to the Advantech via two analog interfaces 4–20 mA and setup was modified to send two process values on these interfaces. Via Modbus TCP, values were being read from Advantech by the main computer, where ML and AI (Machine Learning and Artificial Intelligence) were able to process these values.
Advantech ADAM-6024
Bridge
A mid-layer device with analog and digital I/O plus Modbus TCP and MQTT — added without replacing the legacy machine.
Two analog 4–20 mA signals
Read
The old device's setup was modified to send two process values over its current and voltage interfaces into the ADAM.
Modbus TCP to ML/AI
Process
The main computer reads the values over Modbus TCP, where machine learning and AI process them.
Summary
Our solution allowed us to retrofit an older device and send data via Ethernet to other machines. Interfaces like Modbus TCP, MQTT, or OPC UA have been known for many years, but unfortunately some manufacturers haven’t implemented those in the latest devices. As far as I know, this trend is changing in a good direction. However, I reckon it is still an extensive challenge for laboratories and scientists to completely implement the IoT/IIoT idea into life if devices are not the latest. We have to look for non-standard solutions for data collecting. One way is retrofitting with one additional mid-layer device, but it depends on the current situation.