jmri.jmrit.blockboss
Class BlockBossLogic

java.lang.Object
  jmri.jmrit.automat.AbstractAutomaton
      jmri.jmrit.automat.Siglet
          jmri.jmrit.blockboss.BlockBossLogic

All Implemented Interfaces:

Runnable

public class BlockBossLogic
extends Siglet

Drives the "simple signal" logic for one signal.

Signals "protect" by telling the engineer about the conditions ahead. The engineer controls the speed of the train based on what the signals show, and the signals in turn react to whether the track ahead is occupied, what signals further down the line show, etc.

There are four situations that this logic can handle:

1. SINGLEBLOCK - A simple block, without a turnout.

   In this case, there is only a single set of sensors and a single next signal to protect.

2. TRAILINGMAIN - This signal is protecting a trailing point turnout, which can only be passed when the turnout is closed. It can also be used for the upper head of a two head signal on the facing end of the turnout.

   In this case, the signal is forced red if the specified turnout is THROWN. When the turnout is CLOSED, there is a single set of sensors and next signal(s) to protect.

3. TRAILINGDIVERGING - This signal is protecting a trailing point turnout, which can only be passed when the turnout is thrown. It can also be used for the lower head of a two head signal on the facing end of the turnout.

   In this case, the signal is forced red if the specified turnout is CLOSED. When the turnout is THROWN, there is a single set of sensors and next signal(s) to protect.

4. FACING - This single head signal protects a facing point turnout, which may therefore have two next signals and two sets of next sensors for the closed and thrown states of the turnout.

   If the turnout is THROWN, one set of sensors and next signal(s) is protected. If the turnout is CLOSED, another set of sensors and next signal(s) is protected.

Note that these four possibilities logically require that certain information be configured consistently; e.g. not specifying a turnout in TRAILINGMAIN doesn't make any sense. That's not enforced explicitly, but violating it can result in confusing behavior.

The protected sensors should cover the track to the next signal. If any of the protected sensors show ACTIVE, the signal will be dropped to red. Normally, the protected sensors cover the occupancy of the track to the next signal. In this case, the signal will show red to prevent trains from entering an occupied stretch of track (often called a "block"). But the actual source of the sensors can be anything useful, for example a microswitch on a local turnout, etc.

There are several varients to how a next signal is protected. In the simplest form, the controlled signal provides a warning to the engineer of what the signal being protected will show when it becomes visible:

• If the next signal is red, the engineer needs to be told to slow down; this signal will be set to yellow.
• If the next signal is green, the engineer can proceed at track speed; this signal will be set to green.

If the next signal is yellow, there are two possible varients that can be configured:

• For the common "three-aspect" signaling system, an engineer doesn't need any warning before a yellow signal. In this case, this signal is set to green when the protected signal is yellow.
• For lines where track speed is very fast or braking distances are very long, it can be useful to give engineers warning that the next signal is yellow (and the one after that is red) so that slowing the train can start early. Usually flashing yellow preceeds the yellow signal, and the system is called "four-aspect" signaling.

In some cases, you want a signal to show exactly what the next signal shows, instead of one speed faster. E.g. if the (protected) next signal is red, this one should be red, instead of yellow. In this case, this signal is called a "distant signal", as it provides a "distant" view of the protected signal's appearance. Note that when in this mode, this signal still protects the interveneing track, etc.

The "hold" unbound parameter can be used to set this logic to show red, regardless of input. That's intended for use with CTC logic, etc.

"Approach lit" signaling sets the signal head to dark (off) unless the specified sensor(s) are ACTIVE. Normally, those sensors are in front of (before) the signal head. The signal heads then only light when a train is approaching. This is used to preserve bulbs and batteries (and sometimes to reduce engineer workload) on prototype railroads, but is uncommon on model railroads; once the layout owner has gone to the trouble and expense of installing signals, he usually wants them lit up.

Two signal heads can be protected. For example, if the next signal has two heads to control travel onto a main track or siding, then both heads should be provided here. The faster signal aspect will control the appearance of this head. For example, if the next signal is showing a green head and a red head, this signal will be green, because the train will be able to proceed at track speed when it reaches that next signal (along the track with the green signal).

Author:

Bob Jacobsen Copyright (C) 2003, 2005

Nested Class Summary

Nested classes/interfaces inherited from class jmri.jmrit.automat.AbstractAutomaton

AbstractAutomaton.MsgFrame

Field Summary

static int	FACING
static int	SINGLEBLOCK
static int	TRAILINGDIVERGING
static int	TRAILINGMAIN

Fields inherited from class jmri.jmrit.automat.Siglet

inputs, outputs

Fields inherited from class jmri.jmrit.automat.AbstractAutomaton

promptOnWait

Constructor Summary

BlockBossLogic()
Create a default object, without contents.

BlockBossLogic(String name)
Create an object to drive a specific signal.

Method Summary

void	defineIO() Define the siglet's input and output.
static Enumeration	entries()
String	getApproachSensor1() Return the system name of the sensor being monitored
boolean	getDistantSignal()
String	getDrivenSignal() The "driven signal" is controlled by this element.
static BlockBossLogic	getExisting(String signal) Return the BlockBossLogic item governing a specific signal.
boolean	getHold() Provide the current value of the "hold" parameter.
boolean	getLimitSpeed1()
boolean	getLimitSpeed2()
int	getMode()
String	getSensor1() Return the system name of the sensor being monitored
String	getSensor2()
String	getSensor3()
String	getSensor4()
static BlockBossLogic	getStoppedObject(String signal) Return the BlockBossLogic item governing a specific signal, having removed it from use.
String	getTurnout() Return the system name of the turnout being monitored
boolean	getUseFlash()
String	getWatchedSensor1() Return the system name of the sensor being monitored
String	getWatchedSensor1Alt() Return the system name of the sensor being monitored
String	getWatchedSensor2() Return the system name of the sensor being monitored
String	getWatchedSensor2Alt() Return the system name of the sensor being monitored
String	getWatchedSignal1() Return the system name of the signal being monitored for first route
String	getWatchedSignal1Alt() Return the system name of the alternate signal being monitored for first route
String	getWatchedSignal2() Return the system name of the signal being monitored for the 2nd route
String	getWatchedSignal2Alt() Return the system name of the secondary signal being monitored for the 2nd route
void	retain() Ensure that this BlockBossLogic object is available for later retrieval
void	setApproachSensor1(String name)
void	setDistantSignal(boolean d)
void	setHold(boolean m)
void	setLimitSpeed1(boolean d)
void	setLimitSpeed2(boolean d)
void	setMode(int mode)
void	setOutput() Recompute new output state and apply it.
void	setSensor1(String name)
void	setSensor2(String name)
void	setSensor3(String name)
void	setSensor4(String name)
void	setTurnout(String name)
void	setWatchedSensor1(String name)
void	setWatchedSensor1Alt(String name)
void	setWatchedSensor2(String name)
void	setWatchedSensor2Alt(String name)
void	setWatchedSignal1(String name, boolean useFlash)
void	setWatchedSignal1Alt(String name)
void	setWatchedSignal2(String name)
void	setWatchedSignal2Alt(String name)

Methods inherited from class jmri.jmrit.automat.Siglet

handle, init, setInputs

Methods inherited from class jmri.jmrit.automat.AbstractAutomaton

getCount, getName, getThrottle, readServiceModeCV, run, setName, setTurnouts, start, stop, wait, waitChange, waitMsec, waitSensorActive, waitSensorActive, waitSensorChange, waitSensorChange, waitSensorInactive, waitSensorInactive, waitSensorState, waitSensorState, waitTurnoutConsistent, writeOpsModeCV, writeServiceModeCV

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SINGLEBLOCK

public static final int SINGLEBLOCK

See Also:

Constant Field Values

TRAILINGMAIN

public static final int TRAILINGMAIN

See Also:

Constant Field Values

TRAILINGDIVERGING

public static final int TRAILINGDIVERGING

See Also:

Constant Field Values

FACING

public static final int FACING

See Also:

Constant Field Values

Constructor Detail

BlockBossLogic

public BlockBossLogic()

Create a default object, without contents.

BlockBossLogic

public BlockBossLogic(String name)

Create an object to drive a specific signal.

Parameters:

name - System or user name of the driven signal.

Method Detail

getDrivenSignal

public String getDrivenSignal()

The "driven signal" is controlled by this element.

Returns:

system name of the driven signal

setSensor1

public void setSensor1(String name)

setSensor2

public void setSensor2(String name)

setSensor3

public void setSensor3(String name)

setSensor4

public void setSensor4(String name)

getSensor1

public String getSensor1()

Return the system name of the sensor being monitored

Returns:

system name; null if no sensor configured

getSensor2

public String getSensor2()

getSensor3

public String getSensor3()

getSensor4

public String getSensor4()

setTurnout

public void setTurnout(String name)

getTurnout

public String getTurnout()

Return the system name of the turnout being monitored

Returns:

system name; null if no turnout configured

setMode

public void setMode(int mode)

getMode

public int getMode()

setWatchedSignal1

public void setWatchedSignal1(String name,
                              boolean useFlash)

getWatchedSignal1

public String getWatchedSignal1()

Return the system name of the signal being monitored for first route

Returns:

system name; null if no primary signal configured

setWatchedSignal1Alt

public void setWatchedSignal1Alt(String name)

getWatchedSignal1Alt

public String getWatchedSignal1Alt()

Return the system name of the alternate signal being monitored for first route

Returns:

system name; null if no signal configured

setWatchedSignal2

public void setWatchedSignal2(String name)

getWatchedSignal2

public String getWatchedSignal2()

Return the system name of the signal being monitored for the 2nd route

Returns:

system name; null if no signal configured

setWatchedSignal2Alt

public void setWatchedSignal2Alt(String name)

getWatchedSignal2Alt

public String getWatchedSignal2Alt()

Return the system name of the secondary signal being monitored for the 2nd route

Returns:

system name; null if no secondary signal configured

setWatchedSensor1

public void setWatchedSensor1(String name)

getWatchedSensor1

public String getWatchedSensor1()

Return the system name of the sensor being monitored

Returns:

system name; null if no sensor configured

setWatchedSensor1Alt

public void setWatchedSensor1Alt(String name)

getWatchedSensor1Alt

public String getWatchedSensor1Alt()

Return the system name of the sensor being monitored

Returns:

system name; null if no sensor configured

setWatchedSensor2

public void setWatchedSensor2(String name)

getWatchedSensor2

public String getWatchedSensor2()

Return the system name of the sensor being monitored

Returns:

system name; null if no sensor configured

setWatchedSensor2Alt

public void setWatchedSensor2Alt(String name)

getWatchedSensor2Alt

public String getWatchedSensor2Alt()

Return the system name of the sensor being monitored

Returns:

system name; null if no sensor configured

setLimitSpeed1

public void setLimitSpeed1(boolean d)

getLimitSpeed1

public boolean getLimitSpeed1()

setLimitSpeed2

public void setLimitSpeed2(boolean d)

getLimitSpeed2

public boolean getLimitSpeed2()

getUseFlash

public boolean getUseFlash()

setDistantSignal

public void setDistantSignal(boolean d)

getDistantSignal

public boolean getDistantSignal()

getHold

public boolean getHold()

Provide the current value of the "hold" parameter. If true, the output is forced to a RED "stop" aspect. This allows CTC and other higher-level functions to control permission to enter this section of track.

setHold

public void setHold(boolean m)

setApproachSensor1

public void setApproachSensor1(String name)

getApproachSensor1

public String getApproachSensor1()

Return the system name of the sensor being monitored

Returns:

system name; null if no sensor configured

defineIO

public void defineIO()

Define the siglet's input and output.

Overrides:

defineIO in class Siglet

setOutput

public void setOutput()

Recompute new output state and apply it.

Overrides:

setOutput in class Siglet

entries

public static Enumeration entries()

retain

public void retain()

Ensure that this BlockBossLogic object is available for later retrieval

getStoppedObject

public static BlockBossLogic getStoppedObject(String signal)

Return the BlockBossLogic item governing a specific signal, having removed it from use.

Parameters:

signal -

Returns:

never null

getExisting

public static BlockBossLogic getExisting(String signal)

Return the BlockBossLogic item governing a specific signal.

Unlike getStoppedObject(String signal) this does not remove the object from being used.

Parameters:

signal - system name

Returns:

never null