29 April 2010
Cadalec Ltd is based in Croft, Leicestershire, and has electrical and computer engineers develop HMI, SCADA, PLC and data logging applications. They review client specifications, and then design a system that fully meets the requirements of the end user. They then follow quality assured development practice, while implementing the design to IEC and BS standards. After development is complete, they enter into their own in-house testing that culminates with factory and site acceptance tests and final plant commissioning. For larger jobs, and especially those overseas, Cadalec utilises the in-depth simulation provided by their PICS package, which it claims has reduced business risk and accelerated FAT and SAT phases.PICS Pro I/O simulation software simplifies real-world systems and machines controlled by DCS, PLC and PC control systems. The entire system can be tested (communication, sequencing/interlocking, HMI/SCADA, alarms), all emergency faults can be verified, and operators trained. PICS is a Molex Brad product provided by HardwarePT. The project in hand at Cadalec involved Wonderware InTouch SCADA and large scale automation using ControlLogix PLC’s provided by Rockwell Automation. Cadalec were involved in all aspects of this including the design and build of the automation panels. A key phase of this project was the first time power up of the system, where any errors in cabinet wiring and errors in control and supervision software will start to show up. This frequently causes ambiguity in finding the root cause of a problem; is it in the wiring or the logic, or both? Configuring the PICS package to suit the application and then simulating what is happening provides a reference by which faster debugging can be achieved.PICS Simulation software is designed to allow users to create a dynamic model on a PC that duplicates the behaviour of the I/O devices, providing the control system with simulated device feedback. PICS sits on the automation network and directly interrogates the target controller’s IO.This approach had additional benefits for Cadalec in that the end-user was half a world away and site work had to be efficient and right-first-time. Once the control cabinets were powered up, PICS simulation allowed for fast and accurate debugging. The next phase was the simulation of the agreed FAT (Factory Acceptance Testing); checking that visualisation, reports and alarms were correct according to the Detailed Design Specification. This was greatly facilitated by using PICS as a virtual plant. The following customer-facing FAT went without difficulty and was on schedule. The equipment was then shipped and following installation was then re-commissioned. At this stage simulation plays a very important role; any errors that occur can be confidently attributed to field wiring rather than logic or panel wiring errors. This accelerates debugging and provides for a confident approach. Neale Bassford, technical manager at Cadalec, said, “The software always gets the blame, but thanks to our confidence in the simulation we could set such concerns aside,” adding, “this was probably one of the smoothest commissioning ever.” His assertion was supported when site commissioning was completed not just on schedule, but one week early.Mike Duckles, project engineer at Cadalec added: “We have used PICS for many years and it is a well proven technique that brings benefit to the company, we do not simulate every job with PICS as we have to balance the time of setting up PICS with delivering value to our customers. We always know when to use PICS as it tangibly reduces larger project timelines and significantly reduces project risk.”
Print this page | E-mail this page
This isn't a paywall. It's a Freewall. We don't want to get in the way of what you came here for, so this will only take a few seconds.
Register Now