Any running Chart can be paused by using the system.sfc.pauseChart function. When pausing a chart, any currently executing action steps must finish before the Chart will transition to a paused state. As a result, it may take some time before the Chart fully transitions into the Paused state.
Once the chart is paused, it can then later be resumed. This can be done using the Resume button in the chart control when testing the SFC Monitor Component, or using the system.sfc.resumeChart function.
Canceling a chart works similarly to pausing a chart in that it must first wait for any currently running action steps to finish execution before the chart will cancel. A chart can be canceled from a script by using system.sfc.cancelChart. Normal rules for canceling apply, thus the Chart's On Cancel event will trigger, but not the On Stop event.
Changing the state of a Chart can easily be accomplished without scripting from the SFC Monitor component. From the Client you can simply right-click on a running chart, and click the state you wish the Chart to transition to.
Note that the Chart Lifecycle is still in effect, so only charts in a Paused state may be resumed.