Synchronizing PLC code with a realistic model to create a reliable debugging framework has always been a challenge for off-line virtual commissioning, but development work carried out by Emulate3D on a MicroLogix 1100 series B emulator shows that this is now achievable, according to the company. Emulate3D Controls Testing (ECT) is used to commission automation system controls off line, off the project critical path. This approach, based on replacing the real automation with a reliable 3D virtual model of it connected to the PLC, allows controls designers to verify the correct logical operation of the system without the usual constraints imposed upon them by working under complicated on-site conditions, with limited time available before handover. Emulate3D Inc. has enhanced this approach by creating a MicroLogix 1100 B soft PLC that can read in control code, link to the model and run faster than real time, allowing testing to be completed faster and more cost-effectively than was previously achievable, the company says. Work continues to develop this further into a broader range of widely used PLCs from several manufacturers, including Rockwell Automation, Siemens and Mitsubishi.