Runtime procedural logic

Procedural logic runs at accepted simulation boundaries, outside the continuous DAE residual evaluation. It reads the accepted state, runtime parameters and simulation time, and may update retained modes or explicitly mutable targets before the next solve.

The order shown in the editor is the execution order inside each owning block. If one entry reads a mode written by another entry, place the writer first unless a one-step delay is intentional.

Retained modes

A retained mode is a runtime parameter with an initialization expression. Its value survives between accepted steps. Most procedural entries write one or more modes; DAE equations can read them like any other symbolic parameter.

Using procedural blocks from the Library

The Dynamic Model Editor exposes every concrete procedural type under Procedural logic in both RMS and EMT mode. Drag a leaf onto the canvas, or double-click it to insert it at the center of the visible canvas. Double-click the resulting block to edit its complete declaration in Block Properties → Python code.

Signal-processing blocks expose retained results through ordinary algebraic output ports. Event and switching blocks preserve their real interfaces: flip-flops have separate set/reset inputs, three-phase carrier blocks have three inputs and three outputs, and a conditional diagnostic has no artificial signal output. A delayed switch event requires the target device and switch identifiers to be completed in Python code before the model can be applied.

Available types

• Fixed sample
• Sampled value
• Hard saturation
• Time delay
• Moving average
• Gradient limiter
• Conditional diagnostic
• Delayed switch event
• Flip-flop
• Analog flip-flop
• Pickup/dropoff relay
• Reset on rising edge
• Delayed threshold latch
• Startup handover
• Valve state
• Three-phase carrier PWM
• Three-phase carrier sampled modulation

Use Validate model before applying. Validation checks names, references, expressions, missing modes, duplicate writers and order-dependent reads.