To create a StringIO, click the "Add..." button on the StringIO Table. This will open a new pane with space to enter a System Name and User Name for the new StringIO, and a "Create" button at the bottom.
You must enter a unique System Name. System Names for internal StringIOs have no set pattern. You can call them whatever you want. System-specific StringIOs may have a pattern specific to that system.
The User Name is optional, unless you check "Automatically generate System Name", and if you enter one it has to be unique in your JMRI setup. See the "Names" Help page for more information.
It is also possible to create a number of StringIOs in one go.
Checking the "Add a sequential range" box will enable the "Number of items" field. Set the
number of StringIOs that you wish to add. Clicking [Create] will create a number of
sequentially numbered StringIOs.
If a User Name has been entered, a number will be added to the end of that name (starting
with the second item) to keep each StringIO User Name unique.
Back to the StringIO Table help page.