Replay
3 minute read
The Replay panel plots a CSV file instead of a live controller — useful for looking at a recording after the fact, comparing two runs, or analysing data captured on a machine you cannot reach. It is hidden by default; switch it on in the View menu.
Loading a file
- Click Choose file and pick a
.csvfile. The name appears next to the button. - Click Load.
A toast reports the result, e.g. Loaded 12 traces, 60000 points. Every column becomes a visible trace, the plot
fits the whole recording, and auto-follow is switched off — there is no trailing edge to follow.
From here everything works as with live data: zoom and pan, cursor readouts, measurements, range export, colours, axis assignment and hiding — see Plotting.
Replay and live data are exclusive
Loading a file disconnects an active controller session, and clicking Connect clears the loaded traces. Desk switches modes for you; nothing has to be disabled first. While in replay mode the Parameters tree stays empty, since there is no controller to read.
Accepted CSV format
The first column is the timestamp in milliseconds; X values are plotted relative to the first row, so the plot starts at 0 s. Every other column is one signal, and the header tells Desk what it is:
| Header form | Produced by | Result |
|---|---|---|
Y1 root/path/signal (ch. 0) |
Desk CSV export | Signal on axis y1, channel 0 |
Y root/path/signal |
older Desk exports | Signal on y1 |
root/path/signal[0] |
controller-side recorders | Signal on y1, channel 0 |
Cells that are not numbers (string enums, blanks) are skipped as gaps in that trace, so a mixed file still loads; a column with no numeric data at all becomes an empty trace.
Auto-sort Y axes
When the file carries no axis information in its headers, an Auto-sort Y axes switch appears. With it on, Desk
spreads the columns over y1–y4 by the order of magnitude of their values, so signals of wildly different scale
do not crush each other on one axis. Files exported from Desk already carry their axes, so the switch is not shown
for them.
Note
Auto-sort looks at magnitudes only — it knows nothing about units. Check the assignment afterwards in the Active panel and move traces where you want them.
Large files
Parsing runs in the browser and yields periodically, so the window stays responsive and shows a loading toast. Traces are sized to the file, so no points are dropped. Very large recordings (hundreds of megabytes) are still limited by the memory available to the browser tab — export a narrower time range or fewer signals if loading fails.