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Interacting with a Running Diagram

 You can interact with a running diagram in various ways to observe and test your process, including:

For additional information about interacting with blocks and paths, see Chapter 2, "Using Blocks and Paths".

Displaying the Value on the Path

Every path has a value that is propagated downstream when data input is enabled. The value stored on the path depends on the path type:

Paths of type... Store...
Data
Data-value, which is a number, symbol, or text string.
Inference

Controls paths do not store any data values.

By default, NOL represents the different types of paths, using different colors:

Paths of type... Have this color...
Data paths
Gray
Inference paths

Control paths
Orange

You can customize the default path colors by using the Preferences > Color menu choice, described in "Setting Block and Path Colors".

You determine the value on a path in one of two ways:

Displaying the Path's Table

 You display a path's table when you only need to see the path value temporarily.

To display a path's table:

This figure shows the table for output path of the Noisy Sine block, which sums the output data value of the Sine Wave and White Noise blocks:

.

Note: You cannot enter data into this table; the attributes are read-only.
To hide the path's table:

To move the path's table:

Notice that the path's table contains other information about the path as well:

This path attribute... Indicates...
Quality
Whether the data is ok, expired, or manual
Timestamp
The time at which the block received the data.
Collection-time
The time at which the data arrived into the diagram.
Expiration-time
The time at which the data has expired or will expire.

For more information about these path attributes, see "Using Path Attributes".

Adding a Path Display

You add a path display to your diagram when you want to see the path value at all times.

To add a path display to a diagram:

  1. Clone a path display of the desired type from the Path Displays palette, and place it to the right of the block whose path value you want to display.

  2. Connect the upstream block's output data path to the Path Display.

The current data value is displayed in the path display:


To display the vector value stored on a vector path, use the Vector Path Display on the Path Displays palette.

Displaying a Block's Table

All blocks have an associated table, which displays status information about the block and allows you to enter comments. Some blocks also define an attribute that contains a variable, which keeps a history of the value of the block's output path. For example, all entry points contain attributes for this purpose, for example, dp-out, ip-out, or cp-out and sensor-value. Signal generators contain an attribute named output-value that stores the current sensor value.

To display the table for a block:

The first two attributes provide information about the error status of the block. The Comments attribute contains user-defined notes about a block.

For example, the tables for the Summation block, the Numeric Entry Point, and the Sine Wave look like this:


The table for the entry point contains additional attributes called Dp-out, which contains an embedded variable, and Sensor-value, which is the current value of the external sensor. For Belief Entry points, the embedded variable is Ip-out. For Control Path Entry Points, the embedded variable is Cp-out. For Vector Path Entry Points, the embedded variable is Vpv-out. The table for the signal generator contains an attribute named Output-value, which is the current value of the signal.

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