The "Root Location" tab allows the user to define the location where the outputs should be stored on the file system. Here the user can also configure whether existing files or directories on the file system are to be overwritten or not.
Output to save must be send to the Output Writer via inputs that can be defined on the "Inputs" tab. If you add a new input of type file or directory, you must define the desired target name and path (of the file or directory). Both of them can be created using placeholders:

Target file/directory: The name the file will be given on the local file system. You can insert different placeholders by clicking the “Insert” button. The provided placeholders are:
[Component name]: Name of the Output Writer component in the workflow.
[Input name]: Name of the input you define at the top of this dialog.
[Timestamp]: Date and time at file creation.
[Timestamp at workflow start]: Date and time at workflow start.
[Workflow name]: Name of the workflow.
[Execution count]: Execution count of the Output Writer.
[Original filename]: The name the file/directory had before it was sent to the Output Writer.
It is possible to combine placeholders within a single name.
Target folder: The folder, where the file or directory should be stored. It is relative to the [root] folder (see below). Currently, only one sub folder below the [root] folder is supported. You can either select a folder, which was already used for other inputs or you can “create” a new one just by defining a new folder name within in the text box. Again, the folder name can contain placeholders.
Root folder: The files and directories received via the inputs will be saved to the [root] folder. You can either select the [root] folder at workflow start or you can define a “static” one within the component’s configuration tab below the inputs table. This folder is used on every workflow execution. Note: Defining a static folder might cause problems, if you execute the workflow on another RCE node (e.g. the defined hard drive doesn’t exist on the other machine).
For inputs of simple data types, you only have to specify the type of the input in the “add input” dialog. If you are using such inputs, you have to specify targets on the “Data Sheet” tab. A target receives the values of one or more simple data inputs and writes them into a text file of user-specified format. Several targets can be specified in one Output Writer. However, each input can only be written into one target.
The Output Writer only writes output into a target file when values for ALL of the selected inputs have arrived. I.e. it is expected that for each iteration exactly one value for each of the inputs arrives.
In the “Add target” dialog you have to specify the following:

Target file: The name the file will be given on the local file system. You can insert different placeholders by clicking the “Insert” button. The provided placeholders are:
[Component name]: Name of the Output Writer component in the workflow.
[Timestamp at workflow start]: Date and time at workflow start.
[Workflow name]: Name of the workflow.
Target folder: The folder where the file should be stored. It is relative to the [root] folder (see below). Currently, only one sub folder below the [root] folder is supported. You can either select a folder, which was already used for other inputs or you can “create” a new one just by defining a new folder name within in the text box. Again, the folder name can contain placeholders.
Inputs involved: Here you can select which inputs should be written into the target file. Only inputs of simple data types are shown here. Inputs that are already selected for another target are not selectable.
File header: Here you can define the header of the output file, which will be written once at the beginning of the target file (only if “Append” is selected in the “file handling” dropdown). You can insert different placeholders by clicking the “Insert” button. The provided placeholders are:
[Linebreak]: A linebreak.
[Timestamp]: Date and time at file creation.
[Execution count]: Execution count of the Output Writer.
Value(s) format: Here you can define the format of the input values for one iteration. You can insert different placeholders by clicking the “Insert” button. The provided placeholders are:
[xy]: The received value for a selected input xy.
[Linebreak]: A linebreak. (Linebreaks will not be inserted automatically between iterations).
[Timestamp]: Date and time when the inputs were received .
[Execution count]: Execution count of the Output Writer.
File handling: Here you can select one of the following options:
Append: The standard option where the inputs of all iterations are written to the same file.
Auto-Rename: For each iteration, a new file will be created for each iteration.
Override: Like Auto-Rename, but the file from the previous iteration will be overwritten, so you have one file that only contains the inputs from the last iteration.