Functions Alarms and Events Alarms may be generated in both the workstations and the controllers. The alarm list in the workstation has extensive filter and sorting mechanisms which allow the operator to sort and select which groups of alarms are viewed. Several alarm lists may be configured. Alarms may be placed in classes and each associated with a particular severity.
An EventLog is used to save all alarms and events on a hard drive over a certain period.
Alarms can be inhibited and presented in the list of inhibited alarms.
Historical Data Handling Process variables, Alarms, Operator interactions etc., may be stored as historical data. Such data may be stored as a SattLine Journal or else in an external database via ODBC.
Historical data may be presented as a textual report based on time, a Batch related report, or as historical graphs. Graphics may be incorporated into text reports.
A sophisticated historical data display is available which may be used to view data from one or more journals simultaneously. The time axis may be made absolute or relative by operators.
Batch related information such as recipes, and batch events may also be stored in Journals or in an external database.
Reports The report library can be used to create program controlled reports including graphics, e.g. trend curves.
Batch Handling Using the SattBatch library (compliant with ISA S88.01) gives the user a high level access to batch control. The library can control all batch processes from single paths and products to multi purpose plants. Phases and operations are easily created.
The recipe can describe both a unit recipe and a main recipe for a complete process cell. A graphical recipe editor is used to create the recipes (Revision control for recipes may be implemented). The same display is used to follow the execution of the batch on- line.
Control Loops A wide range of pre-defined modules are available, e.g. PID, filters, ramps, taps and splitters. These modules are graphically connected to each other to create a complete control loop function.
The control loop includes functions for autotuning (automatic setting of control parameters) and gain scheduling with different parameter set-up for different control range. All modules have back-tracking which enables bumpless transfer between auto and manual control.
A function in the PID gives an alarm if oscillations, due to stiction (static friction) in control valves, is detected in the process. To minimize the oscillations a Stiction compensation function can be enabled at the analogue output module.
All modules have a built-in user interface, e.g. the PID module has windows for parameter set-up, variable trend curve display and bar graph representation of setpoint etc.