konnect Issue-date: 27th June, 2019.

Article_1 Integration of OT systems with IT systems

Mr Ramdas Chandrashekar,
ISA Membership No.: 000033629891,
Director (Operations), Advantrak Technologies.

The integration of the data in a meaningful way from Industrial Automation Systems (Operations Technology/OT) as it is described these days, to the Enterprise systems (IT) systems, is a big challenge. There are a lot of connectivity related matters to be taken care of as the automation systems use OPC Classic, OPC- UA, apart from a plethora of Fieldbus systems in achieving the system objectives. The legacy plants may have more of fieldbus technologies like Modbus, Profibus, etc. It will be necessary in such cases to have protocol convertors or other mechanisms to aggregate the data from various field-bus systems and then to push it into an OT-Integration stack. The Discrete manufacturing Operations may in turn have CNC systems where there are controllers from Siemens, FANUC, Okuma, etc. The scenario is quite complicated as the plant operations may have PLC�s and CNC controllers, from which data will have to be funnelled into the OT-IT integration paradigm.

The OT systems will typically work in real-time whereas the enterprise systems will work at more aggregated units of time like shifts and weeks. The major part of the data from the OT systems will be real-time data as control actions cannot wait in any Industrial automation system. Fast response is required. These days we talk about terminology like IoT, IIoT, Industry 4.0, etc. The IoT systems/devices may use some of the aggregated data funnelled into it using JSON/MQTT. Real-time information and Non-real-time Information will be integrated in such a scenario. It is necessary that the aggregated data is also made available in soft real-time format and IoT and higher end enterprise systems use the temporal classification and availability of the data.

An Illustration is appended, below:

Soft real-time integration approach
with MES, IoT, Enterprise systems
Real-time Data Mining and Analysis
Data Aggregation and Temporal and
distinct storage of Data
OPC or equivalent integrated with Plant
floor networks
Automation System - PLC/CNC/DCS

The illustration above shows straight lines between the boxes indicating bi-directional communication. Enterprise systems will be at the top of the illustration, with the automation systems at the bottom.

The data made available after accumulation over OPC and the historian of SCADA software packages, should ideally be aggregated depending on orders of time and stored as distinct database records (requires more investigation and research). It is necessary to extend a producer consumer approach depending on the subscriber application that uses the information. It is important for ISA to investigate and research the approaches and suggest a usage framework for IOT devices, Edge devices, Servers and the Cloud. Security paradigms also must be considered in suggesting the usage framework.

A manufacturing plant or an enterprise that is predominantly working with a combination of OPC Classic and OPC UA in their OT layer and a formal Manufacturing Execution Systems (MES); needs to engineer their MES to work in soft real-time mode to handle soft real-time responses. Data Mining and real-time data analytics must work in the confluence of the OT system and the MES. It is necessary to integrate the older OPC Classic Technology with OPC UA in a manufacturing enterprise, so that reinventing of the wheel is avoided. It will also be needed to integrate pockets of Ethernet/IP, Profinet, Devicenet, CAN etc. into OPC classic, before migrating the information to OPC UA. The best approach that can be evolved may be manufacturing plant specific, but an overall framework can also be evolved by researching the literature and making a meaningful analysis before developing the architecture of the system.

This short article presents a brief overview of an integration framework for OT to IT and some thoughts with respect to the approach that can be followed for the actual integration.