Triggering Plots

Triggering a plot means capturing plot data. Triggering a plot allows you to see data from before you triggered the plot and after you triggered the plot. This is a valuable aid in troubleshooting. For example, if you set up the trigger to contain 25% of the data from before the time the trigger occurred, then the plot will contain data from before the command was issued until some time after it was issued. To specify how much of the plot data is from before the plot was triggered and how much is after the plot trigger, you must use the Trigger Position value.

The default setting is a trigger position of 0%. This means that a triggered plot will not contain data from before the time the plot was triggered. If you set the trigger position to a value other than 0, you will need to manually rearm a plot before it can trigger. Read below for more details.

Note:
Compare triggering a plot to starting a plot with the Start Plot (100) command. The Start Plot command starts plotting immediately and will never contain any past information.
Note:
You can entirely enable or disable the plot trigger by issuing the Enable/Disable Plot Trigger (104) command. A plot cannot be triggered unless the plot trigger is enabled.

Using the Trigger Percentage

The Trigger Percentage specifies how much of the plot data is from before the plot was triggered and how much is after the plot Trigger. The Trigger Percentage ranges from 0% to 100%. If the Trigger Percentage is set to 0%, the triggered plot will not contain any past data. If the Trigger Percentage is set to 100%, the triggered plot will contain only past data. To set the Trigger Percentage, see the Changing the Trigger Settings section below.

If the plot was not re-armed early enough so that the plot has time to capture the data before the trigger occurs, the plot will not include the expected amount of pre-trigger data.

Example:

You have set the Plot Duration to 4 seconds and the Trigger Percentage to 25%. When you trigger a plot, the first 1 second of the plot will contain data from immediately before the trigger occurred, and the last 3 seconds will contain data from immediately after the trigger occurred.

How to Trigger a Plot

Note:
To trigger a plot, the trigger must first be armed. See the Rearming the Trigger section below.
Note:
If a plot is triggered immediately after rearming it, and the trigger percentage is greater than 0%, the plot will not contain any data before the trigger. After rearming, there must be a delay long enough to record the data to fill the plot before the trigger time.

There are two ways of triggering a plot: manually and automatically:

Automatic Trigger

Plots can be automatically triggered by certain conditions. Currently, a plot can be automatically triggered only by motion commands. If automatic triggering is enabled, a plot will trigger every time a motion command is issued to the specified axis.

To set up automatic triggering, see the Changing the Trigger Settings section below.

Note:
The RMC default setting is to automatically trigger plots on motion commands.

Manual Trigger

To manually trigger a plot, issue the Trigger Plot (102) command. You can also issue the Trigger Plot command by choosing Trigger Plot on the Plots menu.

Note:
Even if you manually trigger a plot, the RMC may also automatically trigger plots because it is set to do so by default. To disable automatic triggering, see the Changing the Trigger Settings section below.

Rearming the Trigger

Before triggering a plot, the trigger must first be armed. This tells the RMC to start recording the data in the plot so that when the plot is triggered, it can provide the data. The plot will not trigger if it is not armed. When the RMC starts up, the trigger is armed and therefore prepared to trigger. After triggering a plot, the trigger is no longer armed and must be rearmed before you can trigger a plot again.

The default setting is Automatic rearm. Therefore, you do not need to rearm the plot if you have the default settings.

There two methods of rearming the trigger:

Automatically Rearm

The plot trigger can be set to automatically rearm after it triggers. This is the default RMC plot setting. After a plot triggers, it is ready to be immediately triggered again.

Note:
If you are issuing motion commands in rapid succession, the automatic rearm feature may cause the plots to be cut short when the next plot is triggered. To get long plots, you should change the plot settings to manual rearm. See the Changing the Trigger Settings section below.

Manually Rearm

To manually rearm the trigger, issue the Rearm Plot (103) command. You can also issue the Rearm Plot command from the Plot Manager by choosing Rearm Plot on the Plots menu. To enable manual rearming, see the Changing the Trigger Settings section below.

Rearming a plot will clear all previously captured data for that plot.

Changing the Trigger Settings

The trigger settings can be configured for each individual plot. To change the trigger settings for a plot, follow these steps:

In the Plot Template Editor, on a plot tab, choose Custom.
In the Trigger Settings area, click Edit Trigger Settings.
Make the desired changes and click OK.