Math channels A math channel is a signal computed from other signals. You build it as a small graph — source nodes, operations, one output — and udpscope then treats the result as an ordinary channel. How to reach it The math button in the toolbar, or g. The pane's + adds a channel; opening one shows the graph editor: nodes as boxes, click a box to select it and edit its parameters beside the canvas, click an output port then an input port to wire them, drag a box to move it. The orange dot marks the output node. Worth knowing • The graph is evaluated as an ordered list, so a node may only read ones above it. A cycle is impossible by construction rather than rejected by a check. • A derived channel is a channel. It appears in the signal panel, can be plotted, measured, exported, and used as a source for another math channel. • The math runs on the stored samples — decimated and averaged — so a cutoff you type in Hz means the rate the filter will actually run at. Change the window across a decimation boundary and the coefficients are rebuilt for the new rate. • A source may only name an acquired channel. The stream's timestamp signal is not one: a graph sourced from it validates and then reads NaN for ever, so the dropdown does not offer it. • The output defaults to the last node, and a node added to a linear graph becomes the output. Choosing an earlier node explicitly is respected. • Every numeric field starts at its own identity value — gain 1, offset 0 — not at the bottom of its range. Example [sine] → [gain x2] gives a channel reading y=[-2, 2]. A 100 Hz low pass on the same source passes 50 Hz at 0.97 and 2 kHz at 0.002; a 1 kHz band pass with Q=2 passes 200 Hz at 0.05, 1 kHz at 0.95 and 4 kHz at 0.05. Each derived channel must hold exactly as many samples as the shared clock has time slots.