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, this is notified via both a Sensor becoming ACTIVE and a Reporter being set to the value of the ID Tag. The ID Tag will also record both by which Reporter it was last seen by, as well as the time it was last seen.

If an unknown ID Tag is detected by a reader, details of this tag will be automatically entered into the ID Tag Table.

At system shutdown, the details of all ID Tags known to the system are written to a file stored in the idtags sub-directory of the user files location. The storage of details when and where a given ID Tag was last seen is configurable by setting the option at the bottom of the ID Tag Table.

Current implementations are for CORE-ID based readers. These are supported in stand-alone mode via the 'Generic Stand-alone' protocol and as an up-to 8-way Concentrator using MERG hardware via the 'MERG Concentrator' protocol.
Note: The MERG starter kit as supplied should be configured using the 'Generic Stand-alone' protocol - only when extending the kit with the additional concentrator components should the 'MERG Concentrator' protocol be used.

## 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

Below the table there's an "Add..." button for creating your own ID Tags; JMRI automatically creates ID Tag objects for tags detected on the layout.

Next to it, two check boxes let you activate:

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

### Displaying ID Tags on Panels

An ID Tag can be displayed on a 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. They have their own storage location as described in the first section.