Scope

Scope

Online monitoring samples ten times a second. That is right for a human reading a value and useless for anything short: a pulse one cycle long falls between two samples by construction, and the fault you are chasing is usually exactly that.

The scope is the answer. The panel records up to 8 values every cycle into a ring buffer and stops on a trigger; the editor arms it and draws what came back.

Open it from Online → Scope.

What it records

Signals	8
Samples	256 rows — 2.56 s at a 10 ms cycle
Sampling	every cycle, in the panel, never on the PC
Cost while recording	6 µs per cycle measured on a classic ESP32 at 240 MHz — 0.06 % of a 10 ms period
Cost while disarmed	one comparison — the sampler is not entered at all

The buffer is fixed at 8 × 256 on purpose. A buffer whose size depends on the project is a buffer whose cost nobody can predict, and this one has to be free when it is off.

Using it

1. Pick the signals. The list offers tags and, when the editor and the panel run the same program, the wires between blocks and block members (t1.ET, c1.CV) as well. Up to eight; the counter above the list says how many are left.

2. Set the trigger.

   Mode	Fires when
   now	immediately — fill the buffer once and stop
   rising edge	the source crosses the level upwards
   falling edge	… downwards
   level	the source is at or above the level

   A BOOL source needs no level and is not asked for one.

3. Choose how much history to keep. The pre slider says how much of the ring is kept from before the trigger. This is the point of the whole feature: what happened in the 300 ms before the fault is the part nobody can arm for by hand.

   The number is exact and it is a promise: with 25 % of a 256-row ring the trigger row is row 64, with 64 rows of history behind it — not 63, and never zero because the event happened early. The panel holds the trigger off until that history exists. 4. Arm. The panel records; the editor shows waiting for the trigger, then recording after it, then complete — at which point the rows are pulled automatically and drawn.

The signal list, the trigger and the pre-trigger setting are remembered between sessions. They are stored by name, so they are re-resolved against whatever program is loaded now; a signal that no longer exists is dropped and the page says so. They live in the editor's preferences, not in the project — which signals you happen to be looking at is not a property of the machine.

Reading the picture

• One lane per signal, stacked like a logic analyser. Eight curves on one axis is a picture nobody can read.
• Time is measured from the trigger. Zero is where it fired, everything to the left of it is the history you asked to keep.
• The milliseconds come from the panel's own cycle period, not from a number typed here — a trace labelled with the wrong period is a measurement that lies quietly.
• A BOOL is drawn as a square wave with a filled body. A number gets its own auto-scaled lane, with the range printed under its name; a fixed scale would hide exactly the small movement you opened the scope for.
• Move the mouse over the plot and every lane prints its value at that instant, next to its name. The tooltip adds the row and the time relative to the trigger.
• Wheel zooms, drag pans.

Measuring between two points

Hovering reads one instant; the question an electrician actually asks is how long from this edge to that one.

• Left click plants cursor A, right click plants B. No modifier keys — a person holding a probe in the other hand has one hand for the mouse.
• The span between them is shaded, and the corner reads A -120 ms B +80 ms d 200 ms (5.00 Hz). The frequency is the same measurement asked the other way round, which is what you want when the two cursors sit on consecutive pulses.
• While A is planted, the hover tooltip also gives the time from A and, for numbers, the difference in value — a ramp's slope without doing arithmetic on paper.
• Clear A/B removes them; a new capture clears them by itself, because a cursor belongs to the recording it was placed in.

Getting it out

Export CSV writes one row per sample: the time in milliseconds first (relative to the trigger, exactly as the picture reads), then one column per signal, and a T in the last column on the trigger row. That is the file you send a customer, or open in a spreadsheet next to a measurement from something else.

When it will not arm

The page says	What it means
not online — the scope records IN the panel	there is no connection; this is not a PC-side recorder
the panel runs a different program	the same rule as everywhere: values travel by index, and under a different program they would be values under the wrong names
the Arm button is grey	no signals picked yet, or the editor has no licence — talking to a panel is the paid part

If a recording comes back empty, the trigger never fired — check the source and the level, or use now to see what the signals are doing at all.