Active Text is used to display text strings in response to mnemonics. The purpose of this is to display things that otherwise aren't accounted for on a layout -- or things that we don't have enough information to display. For example, Active Text is used to display things like Power Out and Snow Melter icons.
Additionally, there may be situations where we don't have enough information to display whatever is appropriate. Interlocking with other railroads are good examples of this. In some situations, you may get only a bit that says a railroad has a request for to cross another railroad, but not direction information. In those cases, we can't light an EastboundProceed? or WestboundProceed? signal because we don't know which way the other train is going. So, Active Text is used to indicate that the other railroad has control of the rail.
Usage Information
The format for active text is: StationCallUpLetter:Mnemonic=TextToDisplay
Examples
So, if the station call up letter is "U", an active text string may look something like this:
U:UPG=UP Lined Across BNSF
Which would display the text "UP Lined Across BNSF" on the display whenever a UPG bit is received.
To display symbols or icons, you can use WingDings or similar fonts. An example of this applicaiton is to display a snowflake to indicate snow melter or switch heater operation.
U:SM=T
Note: The letter T in the WingDings font is a snowflake.
Additionally, in TrackBuilder you will want to set the Font of the text field to WingDings (or whatever font you were using). This will make the text field look like a bunch of unreabable icons in TrackBuilder. So, whever an SMK is received from the MCP, or an SMZ is sent from the BCP to the station, a snowflake will be displayed.
Commonly Used Wingdings
In order to prevent us from using 10 different representations for, say, a power out indications, let's build a little list of commonly used WingDing? indicators as suggested standards. The Text Chacter entry is the normal character used to represent the WingDings? icon on the display from the format StationCallUpLetter:Mnemonic=TextToDisplay. Remember to use 0 (zero) for any M0 & P0 indication bits when using active text.