Fly Sky FS-IT4S User manual

Digital proportional radio control system
FS-lT4S
WARNING:
This product is only for 15 years
old or above
INSTRUCTION
MANUAL
Digital proportional radio control system
Copyright ©2013-2017
Flysky RC model technology co., ltd FCC ID:N4ZFLYSKYIT4S

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Thank you for purchasing our product, an ideal radio system for beginners or experienced users alike.
Read this manual carefully before operation in order to ensure your safety, and the safety of others or the
safe operation of your system.
If you encounter any problem during use, refer to this manual first. If the problem persists, contact your
local dealer or visit our service and support website for help:
www.flysky-cn.com/service.asp

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FS-lT4S
Digital proportional radio control system
Table of Contents
1. Safety ................................................................................................................................................4
1.1 Safety Symbols ................................................................................................................................................ 4
1.2 Safety Guide....................................................................................................................................................... 4
2 Introduction ......................................................................................................................................6
2.1 System Features................................................................................................................................................ 6
2.3 Transmitter Overview .................................................................................................................................... 7
2.3.1 Transmitter Antenna ............................................................................................................................ 7
2.3.2 Wheel and Trigger ................................................................................................................................. 7
2.3.3 Status Indicator....................................................................................................................................... 8
2.3.4 Trims ........................................................................................................................................................... 8
2.4 Receiver Overview .......................................................................................................................................... 8
2.4.1 Receiver Antenna ................................................................................................................................... 8
2.4.2 Status Indicator .................................................................................................................................... 8
2.4.3 Connectors .............................................................................................................................................. 8
3 Getting Started ................................................................................................................................. 9
3.1 Transmitter Battery Installation................................................................................................................... 9
3.2 Connecting the Receiver and Servos .....................................................................................................10
4. Operation Instructions .................................................................................................................11
4.1 Power On ..........................................................................................................................................................11
4.2 Binding...............................................................................................................................................................11
4.3 Pre-use Check .................................................................................................................................................12
4.4 Adjusting Wheel Position ...........................................................................................................................12
4.5 Trims ..................................................................................................................................................................12
4.6 Power Off .........................................................................................................................................................12
5. Home Screen ..................................................................................................................................13
6 Function Settings.............................................................................................................................14
6.1 Reverse Function............................................................................................................................................14
6.2 End Points Function ......................................................................................................................................14
6.3 Subtrim Function ..........................................................................................................................................15
6.4 Steering Exponential ..................................................................................................................................15
6.5 Steering Speed................................................................................................................................................16
6.6 Steering Mix.....................................................................................................................................................17
6.7 Throttle Neutral..............................................................................................................................................18
6.8 Throttle Exponential......................................................................................................................................18
6.9 Throttle Curve .................................................................................................................................................19
6.10 A.B.S. ................................................................................................................................................................19
6.11 Throttle Speed..............................................................................................................................................21
6.12 Throttle Middle.............................................................................................................................................22
6.13 Throttle Idel Up............................................................................................................................................22
6.14 Engine Cut......................................................................................................................................................23
6.15 Boat Mode .....................................................................................................................................................23
6.16 Brake Mixing..................................................................................................................................................23
6.17 Mixes................................................................................................................................................................24

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6.18 Display Servos ..............................................................................................................................................24
6.19 Race Timer .....................................................................................................................................................25
6.20 Keys Function................................................................................................................................................25
6.21 Models.............................................................................................................................................................26
6.22 S.V.C (Smart Vehicle Control)...................................................................................................................26
7 RX Setup ...........................................................................................................................................28
7.1 Bind with a receiver.......................................................................................................................................28
7.2 RF std.: ADHDS 2A 2-way............................................................................................................................28
7.3 Receiver PPM Output ..................................................................................................................................28
7.4 RX Battery Monitor........................................................................................................................................28
7.5 Low Signal Alarm ..........................................................................................................................................29
7.6 FailSafe...............................................................................................................................................................29
7.7 Display Sensors...............................................................................................................................................30
7.8 Choose Sensors ..............................................................................................................................................31
7.9 Speed and Distance ......................................................................................................................................31
7.10 i-Bus Setup ...................................................................................................................................................32
7.11 Servos frequency ........................................................................................................................................32
7.12 Range Test .....................................................................................................................................................32
7.13 Update Receiver ..........................................................................................................................................32
8 Spectrum Analyzer ..........................................................................................................................33
9 System Settings ...............................................................................................................................34
9.1 Blacklight Timeout: (Time)..........................................................................................................................34
9.2 Backlight: (%)...................................................................................................................................................34
9.3 System Sound..................................................................................................................................................34
9.4 Alarm Sound....................................................................................................................................................34
9.5 Auto Power Off ...............................................................................................................................................34
9.6 Screen Calibration..........................................................................................................................................34
9.7 Units....................................................................................................................................................................35
9.8 USB Function ..................................................................................................................................................35
9.9 Language ..........................................................................................................................................................35
9.10 Themes............................................................................................................................................................35
9.11 Firmware Update .........................................................................................................................................35
9.12 Factory Reset.................................................................................................................................................35
9.13 About iT4S .....................................................................................................................................................35
10 Product Specification ...................................................................................................................36
10.1 Transmitter Specification (FS-iT4S)........................................................................................................36
10.2 Receiver Specification (FS-iA4B) ............................................................................................................36
10.3 Sensor Specification ...................................................................................................................................37
10.3.1 RPM Telemetry Module (Magnetic, FS-CPD01) ......................................................................37
10.3.2 RPM Telemetry Module (Optical, FS-CPD02) .........................................................................37
10.3.3 Temperature Acuquisition Module (FS-CTM01) ....................................................................37
10.3.4 Voltage Acquisition Module (FS-CVT01)...................................................................................37
10.3.5 i-Bus Module (FS-CEV04)................................................................................................................37
Appendix 1 FCC Statement ..............................................................................................................38

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FS-lT4S
Digital proportional radio control system
1. Safety
1.1 Safety Symbols
Pay close attention to the following symbols and their meanings. Failure to follow these warnings could
cause damage, injury or death.
Danger • Not following these instructions may lead to serious injuries or death.
Warning • Not following these instructions may lead to major injuries.
Attention • Not following these instructions may lead to minor injuries.
1.2 Safety Guide
Prohibited Mandatory
• Do not use the product at night or in bad weather like rain or thunderstorm. It
can cause erratic operation or loss of control.
• Do not use the product when visibility is limited.
• Do not use the product on rain or snow days. Any exposure to moisture (water
or snow) may cause erratic operation or loss of control.
• Interference may cause loss of control. To ensure the safety of you and others,
do not operate in the following places:
• Near any site where other radio control activity may occur
• Near power lines or communication broadcasting antennas
• Near people or roads
• On any pond when passenger boats are present
• Do not use this product when you are tired, uncomfortable, or under the
influence of alcohol or drugs. Doing so may cause serious injury to yourself or
others.
• The 2.4GHz radio band is limited to line of sight. Always keep your model in
sight as a large object can block the RF signal and lead to loss of control.
• Never grip the transmitter antenna during operation. It significantly degrades
signal quality and strength and may cause loss of control.
• Do not touch any part of the model that may generate heat during operation, or
immediately after use. The engine, motor or speed control, may be very hot and
can cause serious burns.

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• Misuse of this product may lead to serious injury or death. To ensure the safety
of you and your equipment, read this manual and follow the instructions.
• Make sure the product is properly installed in your model. Failure to do so may
result in serious injury.
• Make sure to disconnect the receiver battery before turning off the transmitter.
Failure to do so may lead to unintended operation and cause an accident.
• Ensure that all motors operate in the correct direction. If not, adjust the
direction first.
• Make sure the model flies within a certain distance. Otherwise, it would cause
loss of control.

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FS-lT4S
Digital proportional radio control system
2 Introduction
The FS-iT4S transmitter and iA4B receiver constitutes a 4-channel 2.4GHz AFHDS 2A digital proportional
computerized R/C system, compatible with model cars and boats. This system may also be used with the
FS-BS4 receiver to take advantage of Smart Vehicle Control, FLYSKY's state of the art gyro stabilization
technology.
2.1 System Features
The AFHDS 2A (Automatic Frequency Hopping Digital System Second Generation) developed and
patented by FLYSKY is specially developed for all radio control models. Offering superior protection
against interference, while maintaining lower power consumption and high reliable receiver sensitivity,
FLYSKY's AFHDS technology is considered to be one of the leaders in the RC market today.
Bidirectional Communication
Capable of sending and receiving data, each transmitter is capable of receiving data
from temperature, votlage and many other types of sensors, servo calibration and i-BUS
Support.
Multi-channel Hopping Frequency
This systems bandwidth ranges from 2.4055GHz to 2.475GHz. This band is divided in
140 channels. Each transmitter hops between 16 channels (32 for Japanese and Korean
versions) in order to reduce interference from other transmitters.
Omni-directional Gain Antenna
The high efficiency Omni-directional high gain antenna cuts down on interference, while
using less power and maintaining a strong reliable connection.
Unique ID Recognition System
Each transmitter and receiver has it's own unique ID. Once the transmitter and receiver
have been paired, they will only communicate with each other, preventing other systems
accidentally connecting to or interfering with the systems operation.
Low Power Consumption
The system is built using highly sensitive low power consumption components,
maintaining high receiver sensitivity, while consuming as little as one tenth the power of a
standard FM system, dramatically extending battery life.

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2.3 Transmitter Overview
Stylus
LCD
TR1
TR4
TR5
Sw1
Antenna
TR2
Wheel
Sw3
Power
TR3
Sw2
2.3.1 Transmitter Antenna
Precautions:
• For best signal quality, make sure that the antenna is at about a 90 degree angle to the model. Do not
point the antenna directly at the receiver.
• Never grip the transmitter antenna during operation. It significantly degrades the RF signal quality
and strength and may cause loss of control.
2.3.2 Wheel and Trigger
The FS-iT4S has two main control inputs, the wheel and trigger.
• Wheel: Steering, used to control the direction of the model.
• Trigger: Used for acceleration, braking and reverse.

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FS-lT4S
Digital proportional radio control system
2.3.3 Status Indicator
The status indicator is used to indicate the power and working status of the transmitter.
• Off: the transmitter is powered off.
• Blue light: the transmitter is on and working.
• Flashing: low battery or low signal alarm.
2.3.4 Trims
There are 5 groups of trim switches affecting surface position. Each time a trim is toggled, the trim will
move one step. You can hold the trim in the desired direction to make quicker trim adjustments. When
the trim position reaches the middle, the transmitter beeps in a higher tone.
2.4 Receiver Overview
Status Indicator
SENS
SERVO
BIND/VCC
CH1 ~ CH4
Antenna
2.4.1 Receiver Antenna
Attention • For best signal quality, ensure that the receiver is mounted away from motors
or metal parts.
2.4.2 Status Indicator
The status indicator is used to indicate the power and working status of the receiver.
• Off: the power is not connected.
• Lit in red: the receiver is on and working.
• Flashing quickly: the receiver is binding.
• Flashing slowly: the bound transmitter is off or signal is lost.
2.4.3 Connectors
The connectors are used to connect the parts of model and the receiver.
• CH1 to CH4: used to connect the servos, power or other parts.
• BIND/VCC: used to connect the bind cable for binding, and the power cable during normal operation.
• SERVO: used to connect i-Bus module and extend channels.
• SENS: used to connect all kinds of sensors.

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3 Getting Started
Before operation, install the battery and connect the system as instructed below.
3.1 Transmitter Battery Installation
Danger • Only use specified battery.
Danger • Do not open, disassemble, or attempt to repair the battery.
Danger • Do not crush/puncture the battery, or short the external contacts.
Danger • Do not expose to excessive heat or liquids.
Danger • Do not drop the battery or expose to strong shocks or vibrations.
Danger • Always store the battery in a cool, dry place.
Danger • Do not use the battery if damaged.
Follow the steps to install the transmitter battery:
1. Open the battery compartment.
2. Insert a fully-charged battery into the compartment. Make sure that the battery makes good contact
with the battery compartment's contacts.
3. Replace the battery compartment cover.

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FS-lT4S
Digital proportional radio control system
3.2 Connecting the Receiver and Servos
Connect the receiver and the servos as indicated below:
CH1
CH3
CH4
B/C
Switch (Optional)
Battery
CH2
CH3
CH2
CH1
CH4
CH4 Servo
CH3 Servo
Steering Servo
Throttle Servo
Receiver
Servos
Battery

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4. Operation Instructions
After setting up, follow the instructions below to operate the system.
4.1 Power On
Follow the steps below to turn on the system:
1. Check the system and make sure that:
• The battery is fully charged and installed properly.
• The receiver is off and correctly installed.
2. Hold the power button until screen lights up.
3. Connect the receiver power supply to the BIND/VCC port on the receiver.
The system is now powerd on. Operate with caution, or serious injury could result.
4.2 Binding
The transmitter and receiver have been pre-bound before delivery. If you are using another transmitter or
receiver, follow the steps below to bind the transmitter and receiver:
1. Turn the transmitter on, press , and swipe from right to left on the screen and then select [RX
Setup].
2. Check the currect [RF std] and receiver type according to the table below. If you need to change the
standard, select [RF std], and [Yes] in the confirmation box, and then the desired standard.
RF Standard Receiver Type
AFHDS GR3F, GR3E, R6B, R9B
AFHDS 2 iR4, iR4B, iR6B
AFHDS 2A 1-way A3, A6
AFHDS 2A 2-way iA4B, iA6, iA6B, iA10, iA10B, BS4
3. Select [Bind with a receiver] and press [Yes] to enter bind mode.
4. Connect the bind cable to the BIND/VCC port of the receiver.
5. Connect the power to any other port. The indicator will start to flash, indicating that the receiver is in
bind mode.
• For [AFHDS 2A 2-way], once binding is complete, the transmitter should exit the bind menu
automaticlly.
• For other protocols, select to exit the bind menu.
6. Remove the bind and power cable from the receiver. Then connect the power cable to the BIND/VCC
port.
7. Check the servos' operation. If anything does not work as expected, restart this procedure from the
beginning.

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FS-lT4S
Digital proportional radio control system
4.3 Pre-use Check
Before operation, perform the following steps to check the system:
1. Check to make sure that all servos and motors are working as expected.
2. Check operating distance: one operator holds the transmitter, and another one moves the model
away from the transmitter. Check the model and mark the distance from where the model starts to
lose control.
Danger • Stop operation if any abnormal activity is observed.
Danger • Make sure the model does not go out of range.
Attention • Sources of interference may affect signal quality.
4.4 Adjusting Wheel Position
The position of the wheel can be adjusted to be more comfortable to use.
1. Hold the transmitters handle firmly.
2. Grab the plastic underneath the wheel. Do not pull the wheel itself as this could lead to long term
wear and damage.
3. Rotate the wheel out and away from you to the desired position.
Attention • The max rotation is about 45° . Attempting to push beyond the max rotation
can cause damage to the transmitter.
4.5 Trims
Trims allow you to change the centre point of the steering, throttle, channel 3 and 4. For example, if a
model that always turns slightly left, the steering trim can be used to correct the problem. When you
press a trim button the system will jump to the trim interface, once 2 seconds have past and no changes
have made the system will revert back to the home screen.
The System has 5 groups of trim switches located behind the steering wheel.
4.6 Power Off
Follow the steps below to turn off the system:
1. Disconnect the receiver power.
2. Hold the transmitter's power button to turn off the transmitter.
Danger • Make sure to disconnect the receiver power before turning off the transmitter.
Failure to do so may lead to damage or serious injury.

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5. Home Screen
The home screen diplays useful information about your model, including sensors and function status etc.
Model Name Transmitter Battery Status
Receiver Battery Status
Break Mixing
Mixes
Race Timer
Sound
Steering Position
Throttle Position
Channel 3
Channel 4
Steering Trim Position
Menu
Receiver Signal
Sensor Feedback
Throttle Curve
A.B.S.
Engine Cut
Throttle Idle
Boat Mode
Throttle Trim Position
Help
The system's navagation is designed to be easy and quick, using both a stylus and fingers.
• To enter the main menu screen, press the
icon. Then use your finger or stylus to swipe left to right
on the screen to change page.
• To enter a function touch its corrasponding icon. Navagate functions by swiping up and down to
navagate lists and press an item on the list to select it.
• To go back to a previous menu press the icon.
• To quickly enter the sensor menu, touch the RX sensor feedback box. For more information see the
"7.8 Choose Sensors" section of this manual (Page 30).

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FS-lT4S
Digital proportional radio control system
6 Function Settings
6.1 Reverse Function
The Reverse function is used to correct a servo or motor's
direction in relation to the systems controls. For example, if a
steering servo is mounted upside down in order to fit inside a
model, when the system's steering wheel is turned, the servo
will move in the oppisite direction. To fix this, all we need to do
is reverse CH1.
To reverse a channel:
Touch the channel in the list. When reversed, the slider will be at
the [REV].
Select the icon to return to the previous menu.
Select the icon to reset the function.
6.2 End Points Function
Endpoints are the limits of the channels' range of movement. There are two endpoints, one is the low
endpoint and one is the high end point.
To set an endpoint:
1. Select the the channel you wish to change.
2. Move the channel in the direction you want to change
to choose the high or low end point. Alternatively touch
"Down side" or "Up side" in the function menu.
• At the top of the current channel, the selected endpoint
and percentage are shown.
• The endpoints location is shown as a bar and needle.
• The red needle indicates the current setting for the
selected side and channel.
• A real time readout of the channels position can be
seen in this menu as a green bar.
3. Move the wheel at the bottom of the screen left to reduce
the value. or right to increase the value.
Select the icon to return to the previous menu.
Select the icon to reset the function.

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6.3 Subtrim Function
Subtrim changes the center point of the channel. For example, if a car's wheels are slightly out of
alignment, the sub trim could be used to fix this.
To set the subtrim function:
1. Select the desired channel from the list. The setup menu for the selected channel displays.
• At the top of the current channel, the selected channel and percentage are shown.
• The center point location is shown as a bar and needle.
• The red needle indicates the current setting for the selected channel.
• A real time readout of the channels position can be seen in this menu as a green bar.
2. Move the wheel at the bottom of the screen left to reduce the value or right to increase the value.
3. Select the icon to return to the previous menu and save.
• To restore default settings of a single channel, select the icon within its subtrim menu.
• To restore the entire function to default, select the icon in the channel selection menu.
Channel List Subtrim setting and channel's current position
6.4 Steering Exponential
This function changes the steering channel's response curve. There are 2 main parameters:
• Rate: Changes the outer limits of the steering, the default is 100%. Rate cannot be more than 100%.
• Exp. (Exponential): Changes the steering curve, which changes the response of the steering wheel. The
exp setting can be positive or negative.
Changes to the rate and exponential can be seen on the graph located
in the center of the screen. The system also gives a real-time readout
of the channel's current position.
Note:
The system gives a real time readout of the transmitter wheel position.
Other functions effects are not displayed on this graph.

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FS-lT4S
Digital proportional radio control system
By changing the steering curve we can make the wheel more or less
sensitive in different areas of its range of movement, for example,
reducing sensitivity at the middle for more control when making fine
adjustments.
This function must be set as active before use.
To activate the function, make sure that the icon is displayed in the
bottom left corner. If not, press the icon to enable.
Exponential 100%
To set the steering exponential/rate:
1. Select the desired parameter, rate or exp.
2. Move the wheel at the bottom of the screen left to reduce the value or right to increase the value.
Select the icon to reset the function.
Select the icon to return to the previous menu.
This function can be toggled using a switch/button, which is assigned in the [Keys function].
Exponential 0% Rate 64%
6.5 Steering Speed
This function changes the speed in which the steering travels. If the car's wheels are turning too fast, it
could lead to loss of control. On the other hand, if they do not change position fast enough, the car will
become sluggish and slow to make turns. This function is also used to simulate a realistic for scale models.
There are two variables:
• Turn speed: Sets how quickly the wheels turn from their starting position, to the position the system's
control indicates.
• Return speed: Sets how quickly the wheels turn back to their center position.

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To set the steering speed:
1. Select a parameter to change, [Turn speed] or [Return speed].
2. Move the wheel at the bottom of the screen left to reduce the value or right to increase the value.
Select the icon to reset the function.
Select the icon to return to the previous menu.
6.6 Steering Mix
This function changes which wheels are involved in steering, front, rear, or 4 wheel steering. It is set to
[Standard] by default, which means front wheel steering. If want to change the steering mode, select
[Crawler mode]. Note that in crawler mode, CH3 cannot be controled independently.
To enable this function, select [Crawler mode] from the functions main menu.
There are 4 types of steering control:
• Font side: Front wheel steering.
• Rear side: Rear wheel steering.
• Same phase: Front and rear steering at the same time, when turning
a direction all the wheels will turn the same direction.
• Rev. phase (Reverse Phase): The front wheels and back wheels are
both involved in the turning process. However, the rear wheels will
always turn the opposite direction to the front wheels.
To set the steering mix:
1. Select the desired mode, [Standard] or [Crawler mode].
• If you select [Standard], it exits the setting and the front wheels
will turn for steering.
• If you select [Crawler mode], refer to step 2.
2. Select the desired method of steering. The system shows a preview
of the steering method on the screen in real-time when moving the
system wheel.
Select the icon to reset the function.
Select the icon to return to the previous menu.
This function can be toggled using a switch/button, which is assigned in
the [Keys function].

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FS-lT4S
Digital proportional radio control system
6.7 Throttle Neutral
This function sets a "dead zone" for their throttle control, which means that the throttle will not function
while still within the dead zone. You can set up the initial amount of throttle that will be applied when the
throttle leaves the dead zone, for driving forward and backward separately.
To set the throttle neutral:
1. Select [Forward], [Dead zone] or [Backward].
2. Move the wheel at the bottom of the screen left to reduce the value or right to increase the value.
Select the icon to reset the function.
Select the icon to return to the previous menu.
6.8 Throttle Exponential
This function has two variables:
• Rate: Reducing the rate shrinks the outer limits of the curve. As the rate drops below 100%, the graph
will update in real-time. The maximum is 100%.
• Exp. (Exponential): Exponential adds curve. It is possible to move to +-100% creating opposite curves.
Select the icon to reset the function.
Select the icon to return to the previous menu.
This function can be toggled using a switch/button, this is assigned in the [Keys function].

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6.9 Throttle Curve
This function is used to add a curve to the throttle response so that the throttle will respond differently
throughout its range of movement.
This function must be activated and can be assigned to a button (See [Keys Function]).
To set the throttle curve:
1. Activate the function. Make sure that the icon is displayed in the bottom left corner. If not, press
the icon to enable.
2. Select an adjustment point, [L], [2], [3], [4] or [H].
3. Move the wheel at the bottom to change the curve. All changes will be shown in real-time on the
graph. If the trigger is moved, the graph will show the current throttle position.
Select the icon to reset the function.
Select the icon to return to the previous menu.
6.10 A.B.S.
A.B.S. stands for auto breaking system. This function is used to stop the wheels from locking which can
lead to loss of control or a skid. A.B.S. manages this by regulating the amount of pressure the breaks use,
which is done by pumping the breaks on and off rather than a constant force.
There are six sub menus for A.B.S. function setting, [Brake return], [Delay], [Cycle length], [Trigger point],
[Duty cycle], and [Steering mix].
In the submenus, pulses are shown as a square wave, the peaks indicating
brake on, and troughs indicating reduction in braking. As the value
changes, the square wave will change to represent the function's current
settings.
The trigger point is represented as a white line on the graph.
Below the graph is a bar that shows the real-time braking position. When
this function is active and the brake is applied, the green bar will oscillate
in real time showing the A.B.S. in action.