The tube line relied on an S5 PLC as well as a number of analogue control units. In order to improve efficiency, reliablity, and safety, a number of design changes were required. There was a requirement for increased monitoring capacity, and the solution needed to be delivered with minimal downtime.
Through a multi-phase process, I S Systems developed a completely new control system, based on Siemens S7-300 PLC’s and Sinamics DC & AC drives, with communication facilitated by a Profinet network. This solution, as an upgrade to the anologue system, presented the opportunity to greatly reduce physical wiring and mechanical relays. It also allowed for direct interrogation of plant status via the PLC & iba process data acquisition systems.
The system was further enhanced by adding a touchscreen HMI panel, allowing improved operator control and status diagnostics. The HMI was connected to the main PLC network via fibre optics to eliminate electrical noise and interference in the signal.
The control unit for the drives needed precision, as the line moves at 150m per minute, and small errors are very costly. The proposed solution was tested via a rigorous simulated model, designed to test the system for critical timing points to ensure accurate cutting length. The solution prepared as a result of this testing determined the required control loop resolution and our delivered system exceeded this requirement to ensure maximum accuracy.
The solution was manufactured by I S Systems, and went through a vigourous factory acceptance test in the Newcastle workshop, to test both the functionality of the solution and to ensure no faulty components were delivered.
This solution met the requirements of the customer, with time savings delivered through both our simulated and factory acceptance testing.
It is an expectation that comes with the job, to get work done without error and within deadline, but I would like to thank you all for stepping up and getting this project done accurately and ahead of deadline.
Thanks for your good work.