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Modifying NOL Settings

The Settings submenu under the Preferences menu allow you to customize the NOL environment. You use these settings to, among other things:

Reporting Errors

NOL can report errors in the Error Queue and/or to a file. By default, NOL displays errors in the Error Queue only and brings the Error Queue to the foreground whenever an error occurs.

You can configure the following aspects of how NOL reports errors:

To configure how NOL reports errors:

This table describes how to set each attribute:

Attribute Setting
Error File
Specify default error log filename.
Route Errors to File
Set to yes to send errors to error file.
Route Errors to Error Queue
Set to no to avoid sending errors to queue.
Show New Error Queue Entries
Set to no to prevent queue from displaying whenever a a new error is received.
Show Error Message Tracebacks
Set to yes to include internal message traces in error messages.

Setting Startup Preferences

NOL lets you control how it initializes and verifies your application when it starts up. You can also specify a custom procedure that NOL calls when it starts up.

To customize how NOL starts up:

  1. Select the Preferences > Settings > Startup menu choice to display the Startup Settings panel:


  2. Configure the settings as desired, and select OK.

  3. Initialize or Reset NOL to see the effects of the new settings.

Determining Whether Animation and Data Input is Initially Enabled

By default, when you start G2, animation is automatically enabled and data input is disabled.

To disable animation on startup:

To enable data input on startup:

The Animation and Enable Data Input menu choices in the Controls menu will appear checked or unchecked, depending on these startup settings.

Running Your Own Procedure When You Start G2

You can perform your own routine when you start G2. To do this, you create a G2 procedure that takes no arguments.

To run your own procedure when you start G2:

NOL calls the specified procedure after it has finished all its other initialization steps, and before it restarts the scheduler.

To run your own procedure after resetting:

NOL calls the specified procedure after you reset all blocks, using the Reset All Blocks... menu choice on the Controls menu.

Configuring the NOL Environment

You can configure various aspects of the NOL environment, including:

To configure the NOL environment:

  1. Select the Preferences > Settings > Environment menu choice to display the Environment Settings panel:


  2. Configure the settings as desired, and click OK.

Most of the environment settings take effect immediately; reset G2 to see the effects of the keybindings.

Propagating Expiration Events

By default, whenever a block's data expires, the block evaluates using the new expired input, which causes downstream blocks to evaluate. In your application, you might prefer not to have expired data cause blocks to evaluate.

To prevent blocks from evaluating when data expires:

Setting the Sweep Interval

 You can set how the interval at which NOL sweeps the entry points in your diagram. By default, the interval is 1 second, which is the the lowest recommended value.

To process entry point data in a diagram, using a different sweep interval:

For more information on sweeping a diagram, see "Understanding How Blocks Evaluate".

Setting the Animation Delay

You can set the delay for animating blocks and paths. The delay specifies the length of time that a block remains highlighted while it is executing. By default, blocks and paths animate for .01 seconds. Specifying a larger number for the animation delay allows you to observe the blocks as the evaluate, however it will also slow down processing.

To set the animation delay:

Setting the Snap Grid Resolution

 NOL can snap objects to an invisible grid whenever you place them on a workspace or move them. This option helps you align blocks on your workspace to keep it looking neat. For information on using the snap grid, see "Using a Snap Grid".

You can set the resolution of the snap grid in pixels.

To set the resolution of the snap grid:

Setting Allow Other Processing Behavior

 By default, NOL can process 10 blocks when it encounters an allow other processing statement in a procedure. You can customize the number of blocks that can process.

To set the number of blocks that can process when allowing other processing:

Configuring the Key Binding for the Find Block Feature

 You can use the F2 key to search for a block if you know some or part of its name, as described in "Searching for a Particular Block". You can configure the function key that NOL uses to invoke the Find Block feature. The key you choose must be a non-alpha-numeric key, such as a function key.

To configure the Find Block... menu choice key binding:

The allowable keybindings include any G2 key binding, such as Control + n, Alt + n, etc., where n is any character or number.

Setting the Maximum Timeout for Dataseeking

Some blocks use data seeking to obtain value. For example, entry points, signal generators, filters, and charts and graphs all use data seeking. By default, the maximum data seeking timeout is 30.0 seconds. You can set the maximum amount of time that NOL will seek a value before timing out.

To set the maximum timeout for data seeking:

Configuring How NOL Saves Snapshots

Snapshots let you save the state of a running application, as described in "Taking a Snapshot".

You can configure NOL to save snapshot files automatically. You can also configure whether NOL saves the contents of the current window or not, or whether it saves the contents of some other window.

To configure how NOL saves snapshot files:

Specifying the Default Snapshot File

 You can specify the default pathname that NOL uses when saving snapshot files.

To specify the default snapshot file:

If you specify just a filename, NOL uses the current working directory of G2 as the default pathname for the file.

Specifying the Window Whose Contents Are Saved

By default, the Snapshot menu choice saves the contents of the local window. You can specify a different window whose contents are to be saved, or you can specify that the snapshot command save only the KB knowledge and not the contents of the window.

To specify the window whose contents are to be saved:

The default value is local.

Specifying the Priority at Which NOL Saves the Snapshot

To specify the priority at which NOL saves a snapshot:

By default, it is 6, the same priority as the NOL scheduler. Give it a higher priority if you want the snapshot to happen quicker. Give it a lower priority if you do not want the snapshot to slow down your application as much.

Reporting Progress While Saving Snapshot Files

By default, NOL reports its progress as follows when it saves a snapshot file, which is especially helpful when automatically saving snapshot files:


To avoid reporting progress when saving snapshot files:

Saving Snapshot Files Automatically
To save snapshot files automatically:

  1. Set Auto Snapshot to yes in the Snapshot Settings panel.

  2. Set Auto Snapshot Period to a time interval.

NOL begins counting down the snapshot period immediately after you click OK or Apply.

For example, if Auto Snapshot is yes and Auto Snapshot Period is 30 minutes, NOL saves a snapshot every half hour.

NOL saves the snapshot to the file specified in Snapshot Pathname, as described in "Specifying the Default Snapshot File". The default snapshot file is "nol-snapshot.kb".

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