Is Connected (G Dataflow)

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error	error in contains an error
If no error occurred before the node runs, the node begins execution normally. If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.	If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

• Any channel, other than an endpoint, within a route specification string must be reserved for routing or directly hardwired to one of the endpoint channels.
• Channels used as endpoints must not be reserved for routing channels.
• When connecting a route, the list of channels must obey the exclusion rules both explicitly in the route specification string as well as implicitly by any previous connections. Exclusion violations result in an error.

Route specification strings are the paths connecting two channels and are composed of one or more routes delimited by ampersands (&). For example, in the following line of syntax, there are three defined routes or route groups: routeOrGroup & routeOrGroup & routeOrGroup . . .

where routeOrGroup can be any of the following:

• Route name
• Route group name
• Two endpoint channels to be connected that are delimited by ->, for example channel -> channel. Switch Executive dynamically determines the path between the endpoints. A hardwire alias name can be substituted for the endpoints.
• Fully specified path enclosed in square brackets consisting of one or more endpoint channels delimited by ->, for example [channel -> channel -> channel . . .]

  where channel can be the following:

  • A channel alias name
  • A unique name created by combining the IVI device logical name and IVI channel name separated by a slash (/) delimiter, for example device/iviChan
  

  Note  

  Switch Executive has the option of finding an available path at run time by slightly modifying the syntax. Remove the square brackets and enter the two endpoints of a route delimited by a ->.

The following are samples of route specification strings for a matrix:

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error	error in contains an error
If no error occurred before the node runs, the node begins execution normally. If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.	If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.