JMRI: ID Tag Documentation
Author: Matthew Harris
Keywords: rfid tag ID tag model railroad JMRI decoderpro panelpro

# JMRI: ID Tags Documentation

## What are ID Tags?

An ID Tag is JMRI's way of representing information about ID Tags that can be attached to, for example, various items of rolling stock.

When an ID Tag is read by a suitable reader (such as a transponder or a connected RFID reader):

- If the ID Tag is detected for the first time, details of this tag will be automatically entered into the ID Tag Table.
- JMRI will also put the value read into a Reporter and set a Sensor to ACTIVE.
- The ID Tag Table entry will also record which Reporter it was last seen by as well as the time it was last seen.

There are other ways of getting information into the JMRI ID Tag Table, including manually (see below) and via MQTT messages and scripts.]

For general information on using ID Tags with RFID Readers, see Getting Started With RFID.

## How to setup ID Tags

### ID Tag Table

The ID Tag Table provides easy access to the contents of all ID Tags that JMRI knows about.

### ID Tag Table Controls

Id Tags may be entered manually as well as automatically as noted above.

At the bottom of the table window there is an "Add..." button for creating your own ID Tags. Next to this button, two check boxes let you activate:

- Save when and where last seen
- Use Fast Clock Time

### Displaying ID Tags on Panels

There are several ways to display the contents of ID Tags on Layout Editor and Panel Editor Panels. See the references for these editors for details, and Getting Started with RFID for an introduction to this topic (also applicable to other types of ID Tags).

An ID Tag can be displayed on a Panel Editor Panel via the use of the Reporter Icon associated with a given reader. To do this:

- On the Panel Editor window for your Panel, find the "Add Reporter" button.
- In the text box next to that button, type the User Name or System Name of the desired Reporter.
- Click the button. The Reporter icon will be placed on the Panel. If it's not visible, that might be because the value is currently blank; use the Reporter Table to change the value to something that will be visible.
- You can drag the icon to where you want it in the usual way.
- The pop-up menu on the Reporter Icon will let you change the formatting.

More information about Reporters can be found in the Reporters help page.

### Saving ID Tags to disk

ID Tags are not stored with the other tables. Whenever an ID Tag is changed, the details of all ID Tags known to the system are automatically written to a file stored in the idtags sub-directory of the user files location. The storage of when and where a given ID Tag was last seen is configurable by checking the box at the bottom of the ID Tag Table window.