The Warrant List
The Warrant List is a list of all the recorded warrants. For an overview discussion of warrants, see Warrants.
Columns in the Warrant Table
- Warrant - The name of the Warrant.
- Route - The route of the Warrant is listed in a drop down combo box by clicking the table cell.
- Train Name - The Train ID, as stated in the Roster. This cell can be edited and its content is displayed by the Indicator Track Icons when the train occupies their OBlock (the Edit popup of Indicator Track Icons have a checkbox to enable this function).
- DCC Address - The DCC Address of the locomotive or consist. This cell can be edited to correspond to the current motive power of the train.
- Allocate - A button that reserves the route for the warrant. The Indicator Track Icons display green to indicate the route.
- Deallocate - A button that removes the reservation for the warrant.
- Set - A button that allocates and sets the turnouts for the warrant route.
- AutoRun - A button that runs the train over the route according to the throttle commands of the warrant. The recorded speed of the train will be modified according to the occupancy and signal aspects encountered on the route. The Indicator Track Icons display the current position of the of the train with a blue color.
- ManRun - (hidden column) A button that allocates
the warrant and sets the route for a manual operator to run
the train. The script is not run, but the route is
displayed. of the train with a blue color.
(The default setting hides this column. To display it, right click the table header.)
Control/Status - The status of the warrant is
shown. It also has a drop down combo box that can send
commands to a running train.
Note: This column has two functions - Status messages and control buttons.
When running, the warrant will post a status message here; e.g. its current location and speed, error messages, etc.
When clicked the following commands can be sent:
- Halt - Temporarily ramps the train down to a stop and suspends execution of the throttle command script
- Resume - Ramps up the speed of the train to its former setting and restarts the throttle command script
- Move into Next Block - Repeats the test for whether a signal aspect has changed or an occupied block ahead has cleared. If the train has overrun a block where it is expected to be and now appears to be the obstacle preventing movement, this resets its location. (Occasionally a sensor change can be missed due to a short or other hardware malfunction. This reset may allow a stopped train to continue.)
- Stop - Issues an emergency stop to the train and suspends execution of the throttle command script.
- Abort - Abort the script and deallocate the warrant.
- Edit - A button that opens an editing window for the warrant,
- Delete - A button that deletes the warrant.
The Warrant List MenusThe following item are under the Warrants menu.
- Concatenate Warrants - Join two warrants together to become a single warrant. The last block and path of the first warrant must be equal to the first block and path of the second warrant.
- Create New Warrant - After providing system and user names this opens a blank Warrant Editing Window to create a new warrant. The operations of this frame are discussed in Creating and Editing Warrants.
- Train Trackers - Opens window where the identity of trains can be displayed as they move from one occupancy block to another.
- Create NXWarrant - Opens a window to create an eNtry/eXit warrant. this is discussed in About NXWarrants.
- Open Session Log - Opens a window to name a file that records the warrant and train tracking status messages.
Other Warrant List FeaturesThe following items are at the bottom of the window:
The Create NXWarrant button 0pens a window to create an eNtry/eXit warrant.
The Halt all Trains button causes all running warrants to halt their trains.
The Status field contains the last 20 messages from warrants. Click in the field to display them.
Running Automated TrainsThe throttle commands recorded in a warrant can be played back to run the train. When running automated, additional control of the train can done through four choices: Halt, Resume and Abort are commands to halt a running automated train, restart it or stop the train and abort the remaining throttle commands. Move into Next Block is "repair" command should the train overrun a block and become "Lost". This command aligns the warrant to the next block and restarts the train.
Although there are separate operations in the Warrant List table to reserve a Warrant route (Allocate) and set Turnouts and Signals (Set Route) these operations do not have to be done to run an automated train. An AutoRun operation can begin without them. The train will seek allocation and set turnouts as it proceeds on the route. When confronted with an occupied block, the train will stop and wait until the block clears. When the next block is clear but the block beyond the next block is occupied, the train will approach at reduced speed. Similarly, if the Portals have been defined with Signal Heads or Signal Masts protecting the blocks they join, the train will modify the speed according to the appearance or aspect of the signal. An automated train will attempt to secure allocation of the next two Blocks each time it enters a Block. It also checks whether the Block is occupied by an unknown train and will not enter if the Block is occupied.
As a safety feature, whenever a warranted train has permission to enter the next Block, the turnouts are reset. Having permission from Signals means that resetting the turnouts should not interfere with any interlocking logic. In the absence of Signals, occupancy or allocation to another warrant may deny permission. Only clearing the most restrictive of these conditions will give the auto-run train permission to proceed. When such a denial is cleared, the train will proceed automatically. The only thing that overrides having permission to proceed is if the user has set the control to "Halt". The train will not move until the user sets "Resume".
When the Starting block is UnoccupiedIf a warrant is started and the starting block is not occupied, the warrant will wait until the block is occupied. When occupation occurs the warrant will set to the "Halt" and wait for the user to set the "Resume" control. Note it is vital that the correct train occupies the starting block. The address specified in the warrant, is the train that will begin moving.
How Signals Aspects and Block Speeds Modify A Train's SpeedWhen a warrant is running and its train enters a block, it looks ahead to see if any speed changes are coming up. The look ahead distance must be adequate for the train to be able to stop should that be needed. This distance is at least one block and could be several. If a signal or block is encountered within this look ahead distance, and either the aspect of block indicates the speed must be regulated, then the warrant must take action. It needs to inform the engine of the speed changes in a smooth (and hopefully prototypical) fashion and calculate when these speed changes should begin.
A default throttle factor and the layout scale is configured in Preferences under the warrants tab. The ramp up and ramp down parameters, Ramp Step Time and Ramp Step Throttle Increment are also configured there.
Once a speed change is noted by reading a signal aspect or specified block speed ahead, the Warrant must calculate when to begin the speed change (ramp down or ramp up). Both the look ahead distance and the time when to begin the speed change require knowing the track speed. Thus to get train to begin and end its speed changes at the proper points, a factors that relate the throttle settings to the actual track speed is needed. Without such throttle factors a fast running engine may overrun the point where a speed change expects to be completed, or a slow running train may stop too far short of where it is expected..
The throttle factors obviously depend upon the particular engine's power curve. This is a combination of decoder's throttle speed curve and the response of the locomotive motor to the voltage set by the speed curve. It is nearly impossible to set a single throttle factor that will work over the engine's entire speed range in both forward and reverse directions. A complete Speed Profile for every speed step of a decoder can be made with the Roster speed Profiling tool. Alternatively, Speed Profile factors for a selected set of throttle settings for the motive power used in a warrant can be determined by using the NXWarrant Compute Throttle Factor feature. Frequently, calibrating a slow, medium and fast throttle setting for both forward and reverse will be sufficient. See NXWarrants for instructions on how to do this.