Display — Control Systems/Sinks

Display

Control Systems / Sinks

Shows the value reaching it, sample by sample, in the chosen numeric format. It is a readout and nothing else: y is not produced, and u is not altered, rounded or delayed – Format chooses how the number is written down, never what the number is.

Ports

• Input – u, the value to show. Any size [m,n]; the whole matrix is written on one line as [a b; c d]. Exactly one input port, as in Simulink, and the count is not user-editable.
• No outputs – Display is a pure sink and passes nothing on.

Where the value appears

On the block itself, centred in its frame, as Simulink does it – one line per matrix row, updated live as the run proceeds – at most once per Refresh Period (s), so a fast run stays readable – and left showing the final sample when it ends. Nothing is written to the run log. The face is cleared when a new run starts, so a Display never shows a number from the run before. To plot a signal instead of reading it, use Scope; to keep it for later analysis, use Signal Recorder or Record.

Make the block bigger if a wide matrix or a long format does not fit – the readout is drawn at the block's centre and is not clipped, so it will spill past a frame too small for it.

Parameters

• Format – how each number is written, matching MATLAB's formats of the same names:
  • short – fixed point, 4 decimals (the default).
  • long – fixed point, 15 decimals.
  • short_e – scientific, 4 decimals.
  • long_e – scientific, 15 decimals.
  • bank – fixed point, 2 decimals.
• Decimation – show every Nth sample. 1 shows every sample; a value below 1 is treated as 1. The first sample of a run is always shown.
• Refresh Period (s) – the shortest time, in seconds of real time, between one repaint of the face and the next. The default of 1 keeps a long run readable: Decimation counts solver steps, so it speeds up with the solver, whereas this does not. Set it to 0 to repaint on every sample Decimation lets through, which is the right choice for a slow run watched step by step. The first sample of a run is always shown immediately, and so is the last – the final value never waits for a period to expire. This parameter is about reading the number, never about the number: it changes nothing the model computes and nothing any exported core does.
• Sampling Time (s) – zero or less inherits the solver's rate; a positive value runs the block at that period.

Code export

All ten targets: Python, MATLAB, Java, Rust, C, C++, VHDL, Verilog, SystemVerilog and PLC Structured Text. The six software targets print <block path> = [a b; c d] per shown sample, in the same format and gated by the same Decimation count as the face readout – the format is translated to each language's own conversion, so an exported core and the app agree digit for digit. They print rather than paint because a generated core has a console and no block face; the digits are the same, the surface is not. PLC Structured Text has no console, so the function block instead keeps one LREAL per element holding the latest shown value, which is what a display IS on a PLC: a variable an HMI or trace binds to. The three HDL targets report each element into the simulation transcript at the fixed-point word's own precision, so Format does not cross to them – there is no formatted print in a Q16.16 datapath. Decimation is baked into the body at export time in every target; it is structural, not a tunable parameter.

Simulink bridge

Import and export, mapped to simulink/Sinks/Display. "Format" to Format and "Decimation" to Decimation, both pass-through; "Sampling Time (s)" to SampleTime, as on every block. Refresh Period (s) does not cross in either direction and is not reported as lost: it is a preference about how this app repaints a block face, Simulink has no counterpart, and mapping it onto Decimation would change what the model computes to serve a preference about reading it. Floating is always written as off: a wired Display is the only kind this block is, and the floating one is a separate library block (Floating Scope is ICore's counterpart to that idea). Simulink's Format also offers four Stored Integer options – hex, binary, decimal and octal – which have no meaning for a double-precision signal and are therefore not offered here; an imported Display set to one of them reports that the value did not translate and keeps short.

Notes

• Algebraic and stateless as far as the signal is concerned. The Decimation counter is the block's only state, and it counts SOLVER STEPS at the block's own rate, not seconds. Refresh Period (s) is the one thing here measured in seconds, and they are seconds of REAL time, not of simulated time – a run compressing an hour of model time into two seconds still repaints once a second.
• Decimation gates the printing only, and the refresh period gates only the repainting. Code-export verification records this block's input, so a decimated or slowly-refreshed Display is verified exactly like a plain one.