Castings foundry, POK in Mexico is a subsidiary of the Nucor Corporation, the largest steel producer in the United States. POK has moved toward ‘POK 4.0’ in a series of steps over several years, changing from manual to automated systems for more available, immediate, and reliable data. The goal is a plant that predicts and prevents defects, communicates the whole process of casting and machining in real time, and where equipment self-regulates based on current circumstances. POK initially developed an enterprise resource planning (ERP) system in response to a customer request for individual serial number traceability. ERP data input was still manual, but it was a start.
POK casts parts for heavy industries, making pumps, pipes, valves, rotors, impellers, drill heads, and other industrial components. The company produces alloys such as high-strength steel, stainless steel, low-alloy steel, and carbon steel. In addition, it offers melting, state-of-the-art vacuum induction melting, heat treating, CNC machining, a conventional machine shop, and a pattern shop for designs in a variety of materials. Information from all these processes and equipment needed to be integrated.
Focus on customers
POK has long-standing relationships with its customers. Clients often ask the design team for help in making a product to slightly different specifications. With increasing business, the company decided to build a new facility to double its production capacity. Giorgio Moreno, special projects coordinator, was tasked with designing ‘POK Acatlan’ with Industry 4.0 in mind.
The challenge
The question was how to aggregate all process information from the equipment and PLCs and then exchange that information with corporate scada and ERP systems, all at a reasonable cost. Integrating all the processes into a single automation system was a non-starter. POK uses equipment from manufacturers all over the world, and is supplied with PLCs from Rockwell Automation, Siemens and several others. For the new foundry, the team needed to use the best equipment and processes for POK’s needs, regardless of where they came from or the controllers they used. A closed system from a single supplier would limit the options and increase costs dramatically. “We wanted to develop the new factory internally to save costs and avoid recurring costs such as licensing. The main challenge was to communicate with all our equipment without voiding any warranties,” says Moreno.
When he saw the IIoT capabilities of Opto 22’s new groov edge programmable industrial controller (EPIC) and its direct integration with Inductive Automation’s Ignition scada software, he could see the way forward. EPIC and Ignition could integrate data from all the possible equipment and processes they might need to use.
Implementation
The 14 groov EPIC systems POK installed at the edge of the foundry’s network serve multiple purposes: local control, connectivity with PLCs in the separate systems, data acquisition, and secure communications with Ignition.
Each EPIC system consists of an industrial processor and I/O on an eight-module chassis, and is UL Hazardous Locations Class 1 Div 2 approved and ATEX compliant. The sturdy stainless-steel construction of the system and its wide 20 to 70°C operating temperature range fit right into the foundry’s needs. EPIC processors can be programmed with either Opto 22’s flowchart-based PAC Control, or with any IEC 61131-3 compliant language using the CODESYS development system. For this project, Moreno chose CODESYS for programming.
“The digital inputs indicate position switches of the equipment and its moving parts; the digital outputs are for driving solenoids and for lamps to indicate system status to the operator. The thermocouples are for temperature measurement, the 4-20 mA inputs are for temperature and pressure sensors, and the 4-20 mA outputs are for control loops, especially to regulate temperature,” explains Miguel Cuevas, gerente comercial at Opto 22’s distributor in Mexico, IC22, which provided both the Opto 22 and Inductive Automation products.
In addition to local control, the EPIC processors are used for supervisory control, for example to run batch processes. Unlike a standard PLC, they also connect directly to PLCs and other automation equipment such as variable speed drives, Kuka robots, induction ovens, compressors, and much more. They consolidate data from all these and exchange it via Ignition with the ERP and scada systems.
A groov EPIC system can run either Ignition EDGE or Ignition FULL on its processor, but in this case Moreno chose to run Ignition on a separate server. He uses Ignition Tag Historian, Alarm Notification, Perspective, Sequential Function Charts and OPC UA. Postgres, an open-source SQL database, provides the database for Ignition Historian. The flexible ERP is Odoo.
He also uses Ignition to directly monitor power meters, gas meters, resin meters, and sand level meters, which account for some of their largest recurring production costs.
HMIs
Moreno took full advantage of the opportunities for operator interfaces (HMIs), using both Ignition Perspective and the groov View software built into groov EPIC. “We now have a mission control in the centre of our factory, where all Perspective screens display every active part of our process,” he says. “Our operators can view the HMI of any machine using tablets at the machine or even with their mobile device.”
At the same time, the groov View HMI gives him local access to systems. “We were able to use both groov View’s HMI and Perspective simultaneously, and this allows us to have local HMI control should our network connection to the edge ever fail.
“I have an integrated HMI, and I can take advantage of organising my factory into zones, depending on their proximity to a nearby EPIC. I can integrate independent processes such as shelling, inductive furnace and heat treatment, and have a local HMI that allows me to control it with no added costs,” he says.
Results
POK is delighted with the results. Manufacturing is now fully automated, from order entry into the ERP system, to manufacturing the product, to updating finished goods in the same ERP. Operators find that historical reports, process tracking and tracking production make their jobs easier. Every engineer can monitor any part of the plant from a mobile phone, a local tablet, or mission control.
The company estimates it is saving money in many ways: initial outlay, lower recurring costs, improved product quality through tracking, faster new product production with automated orders in the ERP system, and even labour costs.
“We estimate we have saved over 60% of the cost compare to purchasing a turnkey system from a vendor. We don’t have to pay any recurring licensing costs for any of our software. We are not limited by users, devices, tags or screens. Ignition allowed us to use the licences that we had already purchased for our equipment from our first plant, in this second plant,” he added. “With EPIC, I can talk to any PLC that I purchase, whether Rockwell, Siemens or Mueller I/O.”
Labour costs are also significantly less than with a large closed system. Moreno says that because EPIC, CODESYS, and Ignition are so easy to use, they were able to hire recent college graduates to do much of the programming and HMI screens. For example, engineers can transfer skills in any IEC 61131-3 language to CODESYS. You can have two people with experience, and everyone else can be less experienced.
Future plans
“We chose Opto for its simplicity in the development and implementation of projects, because there are no recurring licence costs, and because the support is free. The cost/benefit ratio is excellent,” says Moreno.
Cuevas concludes: “The EPIC took information from field sensors, and made control loops and control logic like any ordinary PLC, with the plus that it communicated with Allen-Bradley drivers, with a KUKA robot that speaks EtherNet/IP, and more. In addition to all this, it shares information with the SCADA Ignition and finally with the ERP Oodo.”
For more information contact Prashanth Gokaran, Opto Africa Automation, +27 82 575 6669, optosales@opto.africa, www.opto.africa
