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JMRI: PanelPro Frequently Asked Questions
- How does
JMRI tie into the rest of my layout?
- JMRI works like a throttle - it sends and listens to
the messages on the "command bus". Nothing more, nothing
less. And that is actually - A LOT - and is the true beauty
of JMRI. In the case of DecoderPro the commands that are
being used and monitored are those related to programming a
loco. In the case of PanelPro the messages/commands that
are being used are those pertinent to block occupancy,
- Each system has its own "command bus" or "computer
interface" - i.e. its own set of commands (think 'command
format') that it uses. This is why you can't use a Digitrax
throttle on an NCE system. Many people refer to the command
bus as a "throttle net" - to distinguish it from the track
bus. And it is important to note that the messages on the
two are not identical in all cases. Some systems are
similar enough to each other in order to make it possible
to use a throttle from one on another ... but this is
relatively rare (very few layouts actually make use of it).
Another solution is CMRI - which has its own command set.
JMRI also is smart enough to "speak CMRI" (as well as the
ability to "speak" Digitrax and NCE and Lenz ... etc.) The
difference being is that CMRI is a command set and hardware
that is focused only on the RR support systems (signals,
turnouts, etc.) and does not have the ability to control or
program trains. And, in point of fact, does not "know"
whether the layout is DC or DCC. Most of the layouts that
have implemented CMRI recently have used the CMRI hardware
and JMRI (PanelPro) for the human interface.
- On DCC layouts the command station is the interface
between the track and the throttle/command bus. You use the
throttle bus to acquire a loco ... and to send control
messages to the command station - which 'forwards' your
throttle changes to the locos ... and to the stationary
decoders ... via either the track -or- command bus (or
- It is possible - some will even say desirable - to
separate your train support (track bus) from your layout
control support. Although it may not be intuitive - you
don't have to use the same system that you use to control
trains to control the turnouts and signals - simply because
messages don't need to cross that boundary. This is why
some have recommended you consider an environment such as
NCE for the trains and CMRI or Digitrax for the layout
- Because Digitrax and CMRI have published their
interfaces there are more products available for layout
control for those two systems than for NCE. Both RR-CirKits
and Team Digital have excellent products out that work for
Digitrax (for instance). As far as I know there are no such
products for NCE. I do not know what is/isn't available for
- PanelPro is still developing at a rapid rate. Many
layouts are already up and running using PanelPro - but the
most recent developments that have just recently been made
available in PanelPro make using it a -lot- easier than it
used to be. Actually, if you are talking just turnouts and
block occupancy then PanelPro has been usable for some
time. Signaling is getting better all the time.
- When you start doing signaling then "everything
changes". Because signaling requires that the block
occupancy and turnout status be used in the decision
process of "what aspect should be displayed on which
signals at this point in time". This requires layout
specific code/logic. I'm assuming that you want a computer
to make these decisions. It is possible to implement a
system where a human being, usually the dispatcher, does
all of the decisions ... the more complex the
layout/signaling system the more errors the dispatcher will
make. And there is also the "workload" issue(s)... but a
computer running PanelPro is usually loafing and has more
than enough power to keep ahead of the needs of the layout.
Implementing layout control (turnouts, block
occupancy, signals, etc.) is not an "easy deal". And, in
my opinion, it is not something you should attempt to
teach yourself - or to do it alone with just the
help/guidance of online lists such as this one. I am not
saying "don't use online" ... I'm saying that if you want
to do this as easily as possible then you should seek out
those who have gone before and enlist their face-to-face
support/guidance. Yes, you can do it your self - no,
that's not the best way to do this and you will find you
make -many- mistakes that will cause considerable delays
and rework. Many layout automation projects have gotten
stalled for just this very reason.
And just so this gets mentioned ... adding
capabilities such as block occupancy detection, computer
controlled turnouts, and signals is not inexpensive and
needs to be budgeted/spec'd out. And you may find that
you will need to re-wire some or even major portions of
your layout in order to support them correctly/at all.
- How do I save my work?
- There are several ways to save
your panel. This is because the program has to store both
configuration (turnouts, sensors, etc) and layout (the
details of your specific panel) information.
Usually, the easiest way is to use just one file to
contain everything. For example, you can store your panel(s)
in a file called "MainPanel.xml" (or something like that),
and set the preferences to load that file. Then, all you have
to do is save that file again whenever you change something.
One caution: Make sure that you still have the panel open
when you save the file! If you close it, then save the file,
it will of course write a version of the file that doesn't
show the panel. And save this file from the "Panels" menu,
using the "Store Panels..." item.
This works because panels are stored with all the
configuration information at that same time (which guarantees
they'll work when reloaded)
- Can I store just the
can store just the "configuration" information in a file,
which you can save without worrying about whether your
panel(s) are open, etc. If you do this, you can also save
your panels to their own, separate files.
To do this:
This puts config info like Turnouts, Sensors etc, but
not panels, in the file. If you also want to save your
currently loaded panels, select "Store Panels and
- Go to one of the table tools (e.g. Route Table) and
pick "Store configuration..." from the "File" menu.
- This will let you select a file name; make sure it is
_NOT_ the same as the panel file name. (e.g. use
"MyConfig.xml" instead of "MyPanel.xml")
- Remember that name and location, then store.
- How can I see my saved
configuration, including Turnouts etc and panels?
- JMRI does not remember the Turnout, Sensor
or Reporter table entries from
a previous JMRI session unless you take specific action to save your
information, and unless you take specific action to instruct JMRI to read
the saved configuration. (This is generally also true of the information
in the other Tables.)
Once you close and reopen a JMRI application, you have
to load your configuration information xml file to see
your Turnouts, Sensors etc. This allows to use JMRI with
different configurations, or go back to an older version
of the configuration when an error was made in your
latest saved version.
To automatically load the file when the program starts:
On subsequent JMRI invocations, all start-up actions are invoked,
including any "start-up" actions you have defined to "Load" a "Panel File".
- Open the Preferences panel.
- Select the Start-up tab.
- From the drop down list at bottom left, select
"Add", then "Open File..."
- In the dialog box that opens, select the file in
which you have stored the configuration/panels.
A new line with this action is added to the list.
- Click "Save" on the Preferences pane to make sure
this is stored.
- Quit the program and restart it to test.
If automatic reloading of the table entries is not desired, it is possible
to manually read a panel file. Under the JMRI "Panels" menu item, select
"Open Panel..." and then locate and select one or more panel files
containing the appropriate information. Select the "Open Panels" button
to read those files into JMRI.
- Where should I put my custom icons and other
- The best place to put your own files is in the
JMRI Preferences directory (all JMRI apps use the same directory).
You should put any locally-modified versions of files here so
they don't get overwritten by a new version of the program.
Any files that the program writes to contain local
information, e.g. roster entries, are also written here.
The location of this varies by computer type:
The easiest way to find the preferences location is to start
a JMRI program, e.g. DecoderPro or PanelPro, select
"Locations..." from the "Help" menu and click on [User Files
- On a Linux machine, look for a
directory in your home directory.
- On a Macintosh, look in the Preferences folder of the
current System Folder if running MacOS 8 or 9, or the
Library/Preferences folder in your user directory on Mac OS
- On Windows, this can be in a number of places depending
on which Windows version you're running and whether you
have multiple users configured; Search for a "JMRI"
directory to find it.
A special treat for Windows users: if you go to the Windows Start
Menu, in the JMRI section, you can select
"Preferences" to have it open that directory for
Make sure you go to the preferences, and not the
original application package. They are kept separate to
simplify updating the program version. You'll know you've
found the right place if you see the preferences files that
store your applications settings:
You can also search for this file to find this directory:
If you have created icons that
you want to be able from the panel editor, put them in a
directory called "resources" in the Preferences directory.
They'll then show up in the "files" part of the selection box
when you press a "Change icon..." button on the panel
For example, if the Preferences directory contains the
files shown below, you'll get the file display shown at the
> ls resources/ decoderpro.gif green.gif
icons red.gif tester.gif > ls resources/icons/ something
tester.gif > ls resources/icons/something/
It's also possible to put your files in the
resources directory within the JMRI distribution
directory that you get when you install the program. This is
not recommended, because files there will likely be
overwritten when you install a future version (a newer
version of a file, perhaps to fix a problem, will overwrite
your copy; the replacement is based on the file's date).
JMRI Configuration Files