Process Control System
Version Upgrade of a Field-Proven Control System
Version 8.1 offers an expanded block library providing standard solutions for even more automation tasks. This also facilitates engineering since in many cases there is no need for complex programming of individual blocks. The blocks in the library only have to be parameterized, and they have the advantage that they can always be further developed within the scope of Siemens service and support measures. They also remain fully functional following updates. The MPC-10x10 block that supplements the previous MPC 4x4 block is worthy of special mention. This model-based predictive controller can now control up to ten manipulated variables and controlled variables. It can be used for simple implementation of demanding multi-variable control tasks. Expansion of the variables enables optimal operation of distillation towers, for example, with regard to product yield and energy use.
A range of further improved details, such as the option of saving centralized color schemes for operating screens, or the ability to scale the display size of individual block screens, ensure reduced complexity in application-specific configuring, and stronger focus on essential tasks.
More User-Friendly Operation
During ongoing plant operation, the operating personnel use the control system for several hours a day. Therefore a further increase in the user-friendliness of the system was a priority in the development activities for Version 8.1 of Simatic PCS 7. The concept of Advanced Process Graphics makes a crucial contribution here. Its approach is oriented around the EEMUA Publication 201 and the German VDI/VDE Standard 3699 “Process control using display screens”. It is aimed at implementing display concepts task-specifically and situation-specifically. Work is simplified significantly thanks to the consistent use of subtle colors, simple shapes and unambiguous picture language, as well as pre-processed plant data in the form of hybrid displays, trend curves, and “spider charts”. Instead of the plant operator having to establish relationships between individual values in his head — something that requires attentiveness and is prone to errors — the system presents him with important trends and reliably visualizes the overall relationships in production processes. The Advanced Process Graphics simplify the operators’ work despite the increasing complexity and expansion of the classic operator tasks.
Drastic reductions in screen selection times also ensure increased user-friendliness and heightened attentiveness: picture build-up used to take several seconds, particularly with complex operating screens containing a host of process values displayed in real time. Not only is this dangerous at critical moments, it is also perceived as a burdensome nuisance in day-to-day work. Thanks to improvement measures, even highly detailed and large operating screens with a host of variables can now be built-up significantly faster, contributing a great deal to increased safety and smoother working.
The new version now also fully supports the use of the Simatic HMI Comfort Panels. These local operator units ensure detailed display of process screens, ensure fast picture build-up, and offer diverse interfaces such as Ethernet or USB.
Plant managers benefit quickly from updates without having to worry that production will be interrupted. More on the next page.