The chart shows channel values over time. It is docked at the bottom of the window, just above the status bar, and stays there on every page. Charted channels keep updating while you work on other pages or scroll the channel list.
Accessing
The chart appears as soon as you add a channel to it. It goes away when you remove the last one.
-
Open the Channels page.
-
Open a channel's menu: click ⋮ at the end of the row, right-click the row, or press and hold it on a phone or tablet.
-
Click Show in chart.
Show in chart is offered for numeric channels (such as analog, current, temperature, resistance, frequency, counter and ratiometric) and for digital channels. It is not offered for a disabled channel or for one without a single value, such as a bus.
The chart panel
The top of the panel holds the legend on the left and the chart controls on the right. The plot is below.
Legend
Each charted channel has an entry in the legend with:
-
A colour swatch matching its line.
-
Its alias, or its net name when it has no alias. Hover over the entry to see the net name.
-
The latest value and its unit.
-
A Y1 / Y2 button for its axis.
-
An × button that removes it from the chart.
Controls
-
Live: shown only after you zoom or pan. Click it to go back to the latest values.
-
Depth (s): how many seconds of history the chart shows and keeps.
-
Remove every signal: clears the chart.
-
Hide the chart / Show the chart: folds the panel down to its legend, or opens it again.
Adding and removing signals
-
To add a channel, click Show in chart in its row menu on the Channels page. Each new signal gets its own colour.
-
To remove one channel, click × on its legend entry, or click Remove from chart in its row menu.
-
To remove every channel, click Remove every signal in the chart controls.
Digital channels are plotted as 0 (off) and 1 (on). Ratiometric channels are plotted in percent.
Using two axes (Y1 and Y2)
Every signal starts on the left axis, Y1. When you chart values with very different ranges, for example a voltage and a current, move one of them to the right axis.
-
In the legend, click the Y1 button of the signal you want to move.
-
The button changes to Y2 and the signal is drawn against the right axis.
-
Click Y2 to move it back to the left axis.
The right axis is shown only while at least one signal is on it.
Depth
The depth sets how much history the chart shows. It is 60 seconds by default.
-
In the chart controls, type a new number of seconds in the depth box.
-
Press Enter or click somewhere else.
You can set from 5 to 3600 seconds (one hour). Values older than the depth are dropped.
Update rate
The chart reads its channels at the same interval as the channel list. Change the interval in the bar on the Channels page. The default is 1000 ms.
Zoom and pan
In live mode the chart moves with the clock, with the newest values on the right.
-
Zoom: turn the mouse wheel over the plot. It zooms in time around the pointer. On a touch screen, pinch with two fingers.
-
Pan: drag the plot left or right. On a touch screen, drag with one finger.
-
Zooming or panning stops the chart from moving, so you can look at one moment. New values are still recorded.
-
Back to live: double-click the plot, or click Live in the chart controls.
Resizing and hiding the panel
-
Drag the top edge of the chart panel up or down to make it taller or shorter. The panel always leaves some room for the page above it.
-
Click Hide the chart to fold the panel down to its legend. The chart keeps recording while it is hidden. Click Show the chart to open it again.
On a computer, the chart sits beside the side menu. On a phone, it spans the full width.
What is remembered
The chart is saved in your browser. When you reload the page or come back later in the same browser, it picks up where it left off:
-
The charted channels, their colours and their axes.
-
The depth.
-
The recent values, up to the depth.
-
The panel's height, and whether it is hidden.
Another browser or computer has its own chart, which starts empty.
Tips
-
Put signals with different units on different axes, so both are easy to read.
-
Raise the depth to watch slow changes such as temperature drift. Lower it to see fast changes in more detail.
-
Hide the chart when you need the room, instead of removing the signals. It keeps recording.
-
If a message says the charted values could not be read, check the connection state in the status bar.
-
The latest value in the legend is a quick way to watch a channel from any page.