DCS/PLC-based advanced process control is an APC engineering service that designs and implements advanced control logic directly inside your existing DCS or PLC, with no external host computer and no OPC build-out, so plants get a robust, self-contained alternative to model predictive control (MPC, like DMC/RMPCT) at a fraction of the cost.
After a detailed process analysis, PiControl can easily and honestly recommend which control logic will give the best results: DCS/PLC-resident advanced process control or model predictive control (MPC, like DMC/RMPCT). Many times the DCS/PLC-based approach is superior, achieving more monetary benefit and outperforming MPC or any other APC technology.
PiControl technology can be wholly implemented inside any existing DCS/PLC system without a need for an external computer, added peripherals, or OPC configuration. That saves the extra time and effort of configuring a separate computer on both the systems and applications sides.
During project execution, all base-level PID tuning is performed using closed-loop, ultra-short-duration data without open-loop step tests, so the plant stays in normal production while the underlying loops are conditioned for the APC layer built on top of them.
The APC logic is optimized and mathematically calculated using PiControl's PITOPS, then handed to the end user for later maintenance. Once live, every PID and APC tag inside the DCS/PLC is continuously monitored with PiControl's APROMON, so control quality is visible, not assumed.
PiControl Solutions has extensive skills and experience in DCS/PLC-resident advanced process control design and start-up, building the APC logic inside your existing DCS/PLC or on a new PLC attached to it. The design approach is faster, cheaper, and requires less maintenance than model predictive control, and it will not be black-box like MPC (DMC/RMPCT) but can be understood and maintained far more easily.
75% of industrial processes are sequential with a diagonal control matrix, making them well suited to DCS/PLC-based APC without a full-blown MPC or any other APC technology. The feedback corrective action from mathematically optimized DCS tuning parameters provides crisp, stable, tight control action, and PiControl has repeatedly outperformed model predictive controllers at other sites using this approach. The approach also handles nonlinearities, valve or sensor problems, grade transitions, and rapidly changing capacities that trip up rigid control schemes.
PiControl provides a document detailing project implementation guidelines, conditioning base-level PID loops, and developing the APC configuration, plus complete switching and activation logic with a dedicated APC screen to change over between APC and normal DCS operation. Safe start-up procedures, safety clamps, and other guidelines ensure the APC goals are achieved safely and reliably, and PiControl provides advanced process control training to end-user engineers during and after project execution.
The goal of a well-designed DCS/PLC-based APC strategy is to keep the unit operating close to maximum possible profit, safely and reliably. PiControl typically expects a minimum 2-4% improvement in operating efficiency, production, or utility reduction, in some cases up to 10%, along with a 30-50% or greater reduction in oscillation amplitude that enables smoother, faster, more stable running of every control loop it touches.
Energy savings from PiControl's APC implementations typically fall in the 3-15% range depending on the process and current operations, and utility-management strategies can be designed to reduce utility costs by up to 60% while also optimizing energy production such as boiler loads or gas turbines. Product quality matters just as much: many companies report a reduction in standard deviation of product quality of up to 50%, and organizations commonly see a 2% yield improvement by optimizing reactor temperature, feed-to-catalyst ratio, or the separation section.
Grade transitions and disturbances are where DCS/PLC-based APC pays off further. It's common to achieve a 20-50% reduction in grade transition time using the right strategy, so plants can produce grades when they are in demand instead of rejecting difficult transitions. The same strategy helps emission equipment such as furnaces and boilers run closer to their limits without violating them, and it continuously corrects for upstream and downstream disturbances instead of letting them pass straight through to the unit.
All APC logic designed and implemented inside your existing DCS/PLC is optimized and mathematically calculated using PiControl's PITOPS, which is then handed to your team for ongoing maintenance. The same closed-loop identification PITOPS uses to build the APC layer is what conditions the underlying base-level PID loops; engineers who need only that layer can look at PiControl's PID tuning consulting service on its own.
Once the APC is live, PiControl's APROMON continuously performs online control quality monitoring of every PID and APC tag inside the DCS/PLC, so degradation is caught and addressed rather than discovered after the benefit has already eroded.
PiControl's DCS/PLC-based APC approach delivers significant cost savings, fast commissioning, and fast project completion compared to other APC technologies. Data analysis for support and improvement can be conducted remotely and very efficiently, with any resulting changes then made on site by a compact team of local and remote engineers.
Before starting an expensive project using costly consulting services and multivariable or model-predictive software, contact PiControl first. PiControl's approach typically costs less than one-tenth the price of those alternatives while delivering the fullest benefits potential, and PiControl will send design strategies and ideas and assist remotely with easy but powerful process control software tools.
How it compares to MPC, what results to expect, cost, and how to get started.
Ready for advanced process control without an external computer or a black-box MPC bill? Schedule a consultation and a PiControl engineer will assess your process, recommend the right approach, and outline the expected benefits before any work begins.