Many LabVIEW nodes such as VIs contain error in or error out parameters you can use to manage errors. These parameters typically provide the same, standard functionality. When a node exhibits different parameter functionality, the exceptions are documented in the reference material for that node. Standard behaviour error in and error out described is as follows

Note Some nodes, such as error handling VIs, contain an error in parameter that does not provide standard error in functionality, but that contains an error in cluster that is standard.
error in describes error conditions that occur before this node runs. The default is no error. If an error occurred before this node runs, the node passes the error in value to error out. This node runs normally only if no error occurred before this node runs. If an error occurs while this node runs, it runs normally and sets its own error status in error out. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.
error out contains error information. If error in indicates that an error occurred before this VI ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error.

The error in cluster contains the following cluster elements:

status is TRUE (X) if an error occurred before this node ran or FALSE (checkmark) to indicate a warning or that no error occurred before this node ran. The default is FALSE.
code is the error or warning code. The default is 0. If status is TRUE, code is an error code. If status is FALSE, code is 0 or a warning code.
source specifies the origin of the error or warning and is, in most cases, the name of the node that produced the error or warning. The default is an empty string.

error out contains the following cluster elements:

status is TRUE (X) if an error occurred before this node ran or during the running of this node or FALSE (checkmark) to indicate a warning or that no error occurred before this node ran or during the running of this node.
code is the error or warning code. If status is TRUE, code is an error code. If status is FALSE, code is 0 or a warning code.
source specifies the origin of the error or warning and is, in most cases, the name of the node that produced the error or warning.