JMRI: StringIOs

# JMRI: StringIO Documentation

since 5.11.2 A JMRI StringIO object usually connects to some ability of a hardware system to get and put strings.

## The StringIO Table

The StringIO Table lets you see what StringIOs have been defined, what value they currently contain, and to send new values to the layout. You can type a new string value into a StringIO.

#### StringIO Table controls

- Below the StringIO Table you'll find the Add... button to add new StringIOs. The exact format of the hardware address depends on what type of hardware is being addressed. Consult the documentation for StringIOs for your particular connection type. Internal StringIOs, which don't connect to hardware, use a free-form name: Any alphanumeric characters except dollar sign ($) colon (:) and quotes.

## Using StringIOs with LogixNG

A LogixNG can test a StringIO for particular contents, and set the contents of a StringIO to whatever string is needed. See Read string and set string. An example IF statement is at StringIO expression.

### Saving StringIOs to disk

StringIOs are kept in your layout configuration, along with Turnouts, Sensors, Signal Heads, etc. To store this information on disk, allowing you to reload it next time you run JMRI, see Loading and Storing Your Work.