Casio 5231 Operation Guide

MA1111-EA

Operation Guide 5231

About This Manual

Depending on the model of your watch, display text x appears either as dark ﬁ gures on a light background, or light ﬁ gures on a dark background. All examples in this manual are shown using dark ﬁ gures on a light background. Button operations are indicated using the letters shown

in the illustration.

Note that the product illustrations in this manual are intended for reference only, and so the actual product may appear somewhat different than depicted by an illustration.

Things to check before using the watch

1. Check the battery power level.

Congratulations upon your selection of this CASIO watch.

ENGLISH

E-1

E-3E-2

Is H or M indicated as the battery power indicator (page E-15)?

Battery power indicator

E-4

2. Check the Home City and the daylight saving time (DST) setting.

Use the procedure under “To conﬁ gure Home City settings” (page E-26) to conﬁ gure your Home City and daylight saving time settings.

Important!

Proper World Time Mode data depends on correct Home City, time, and date settings in the Timekeeping Mode. Make sure you configure these settings correctly.

3. Set the current time.

x To set the time

See “Conﬁ guring Current Time and Date Settings” (page E-31).

The watch is now ready for use.

E-6

E-36 Using the World Time Mode

E-36 To enter the World Time Mode E-36 To view the time in another time zone E-37 To specify standard time or daylight saving time (DST) for a city E-38 To swap your Home Time and World Time Cities

E-39 Using the Stopwatch

E-39 To enter the Stopwatch Mode E-40 To perform an elapsed time operation E-40 To pause at a split time E-40 To measure two ﬁ nishes

E-42 Using the Countdown Timer

E-42 To enter the Countdown Timer Mode E-42 To specify the countdown start time E-44 To perform a countdown timer operation E-44 To stop the alarm

E-8

YES

The watch is charged. For details about charging, see “Charging the Watch” (page E-11).

Go to step 2.

Power is low. Charge the watch by placing it in a location where it is exposed to light. For details, see “Charging the Watch” (page E-11).

Contents

E-2 About This Manual

E-4 Things to check before using the watch

E-11 Charging the Watch

E-20 To recover from the sleep state

E-21 Mode Reference Guide

E-25 Timekeeping

E-26 Conﬁ guring Home City Settings

E-26 To conﬁ gure Home City settings E-29 To change the Daylight Saving Time (summer time) setting

E-31 Conﬁ guring Current Time and Date Settings

E-31 To change the current time and date settings

E-45 Using the Alarm

E-45 To enter the Alarm Mode E-46 To set an alarm time E-47 To test the alarm E-48 To turn an alarm and the Hourly Time Signal on and off E-48 To stop the alarm

E-50 Illumination

E-50 To turn on illumination manually E-51 To change the illumination duration E-54 To turn the auto light switch on and off

E-57 Hand Home Position Adjustment

E-57 To adjust home positions manually

E-60 Moving the Hands for Easy Viewing of the Digital Dials

E-61 To move the hands to view a digital dial E-62 To return the hands to their normal positions

E-5

E-7

E-9

Operation Guide 5231

E-63 Other Settings

E-63 To turn the button operation tone on and off E-65 To turn Power Saving on and off

E-67 Troubleshooting

E-69 Speciﬁ cations

E-10

Warning! Leaving the watch in bright light for charging can cause it to become quite hot. Take care when handling the watch to avoid burn injury. The watch can become particularly hot when exposed to the following conditions for long periods.

On the dashboard of a car parked in direct sunlight Too close to an incandescent lamp x Under direct sunlight x

E-12

Power Levels

You can get an idea of the watch’s power level by observing the battery power indicator in the lower digital dial.

Battery power indicator

Charging the Watch

The face of the watch is a solar panel that generates power from light. The generated power charges a built-in rechargeable battery, which powers watch operations. The watch charges whenever it is exposed to light.

Charging Guide

Important!

Allowing the watch to become very hot can cause the digital displays to black out. The appearance of the LCD should become normal again when the watch returns to a lower temperature. Turn on the watch’s Power Saving function (page E-19) and keep it in an area

normally exposed to bright light when storing it for long periods. This helps to ensure that power does not run down. Storing the watch for long periods in an area where there is no light or wearing it in

such a way that it is blocked from exposure to light can cause power to run down. Expose the watch to bright light whenever possible.

Level

(L and

LOW)

(CHG)

The ﬂ ashing x LOW message at Level 3 (L) tells you that battery power is very low, and that exposure to bright light for charging is required as soon as possible.

Whenever you are not wearing the watch, leave it in a location where it is exposed to light.

Best charging

performance is achieved by exposing the watch to the strongest light available.

Battery Power Indicator

(H)

(M)

5 All functions disabled.

All functions enabled.

Illumination and beeper disabled. Except for Timekeeping Mode, all other modes disabled.

All functions and display indicators disabled except for timekeeping and display of CHG (charge) in the lower digital dial. Hour and minute hands stopped at 12 o’clock.

When wearing the watch, make sure that its face is not blocked from light by the sleeve of your clothing.

The watch may enter a

sleep state (page E-19) if its face is blocked by your sleeve even only partially.

Function Status

E-11

E-13

E-14

At Level 5, all functions are disabled and settings return to their initial factory x defaults. Once the battery reaches Level 2 (M) after falling to Level 5, reconﬁ gure the current time, date, and other settings. Display indicators reappear as soon as the battery is charged from Level 5 to

Level 2 (M). Leaving the watch exposed to direct sunlight or some other very strong light x source can cause the battery power indicator to show a reading temporarily that is higher than the actual battery level. The correct battery level should be indicated after a few minutes. The current time and all other settings return to their initial factory defaults

whenever battery power drops to Level 5 and when you have the battery replaced.

E-16

Charging Times

Exposure Level (Brightness)

Outdoor sunlight (50,000 lux)

Window sunlight (10,000 lux)

Window sunlight on cloudy day (5,000 lux)

Indoor ﬂ uorescent lighting (500 lux)

1 Approximate exposure each day to generate power for normal daily operation. * 2 Approximate exposure time (in hours) required to take power up one level. *

The above exposure times all are for reference only. Actual exposure times depend

on lighting conditions.

E-18

Daily

Operation

Level 5 Level 4 Level 3 Level 2 Level 1

8 min. 3 hours 28 hours 8 hours

30 min. 8 hours

48 min. 13 hours

8 hours 180 hours – – – – – –

Level Change *2

105 hours

170 hours

28 hours

46 hours

Power Recovery Mode

Performing multiple illumination, beeper, and/or high-speed hand movement x operation during a short period may cause all of the battery power indicators (H, M, and L) to start ﬂ ashing in the lower digital dial. This indicates that the watch is in the power recovery mode. Illumination, alarm, countdown timer alarm, and hourly time signal operations will be disabled until battery power recovers. Battery power will recover in about 15 minutes. At this time, the battery power

indicators (H, M, L) will stop ﬂ ashing. This indicates that the functions listed above are enabled again. If all of the battery power indicators (

x H, M, L) are ﬂ ashing and the CHG (charge)

message also is ﬂ ashing, it means the battery level is very low. Expose the watch to bright light as soon as possible. Frequent ﬂ ashing of all of the battery power indicators (

x H, M, L) probably means

that remaining battery power is low. Leave the watch in bright light to allow it to charge.

For details about the operating time and daily operating conditions, see the “Power x Supply” (page E-70) section of the Speciﬁ cations.

Power Saving

When turned on, Power Saving enters a sleep state automatically whenever the watch is left for a certain period in an area where it is dark. The table below shows how watch functions are affected by Power Saving.

For information about enabling and disabling power saving, see “To turn Power

Saving on and off” (page E-65).

There actually are two sleep state levels: “display sleep” and “function sleep”.

Elapsed Time in Dark Digital Dials Operation

60 to 70 minutes (display sleep) Blank

6 or 7 days (function sleep) Blank

Digital dials are off, but all functions are enabled.

Hour and minute hands stop at 12 o’clock. All functions are disabled, but timekeeping is maintained.

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Operation Guide 5231

The watch will not enter a sleep state between 6:00 AM and 9:59 PM. If the watch x is already in a sleep state when 6:00 AM arrives, however, it will remain in the sleep state.

The watch will not enter a sleep state while it is in the Stopwatch Mode or Countdown Timer Mode.

To recover from the sleep state

Move the watch to a well-lit area or press any button.

E-20

Selecting a Mode

The illustration below shows which buttons you need to press to navigate between modes. To return to the Timekeeping Mode from any other mode, hold down x C for at least four seconds.

Timekeeping Mode World Time Mode

C C

E-22

General Functions (All Modes)

The functions and operations described in this section can be used in all of the modes.

Auto Return Features

The watch returns to the Timekeeping Mode automatically if you do not perform any button operation for two or three minutes in the Alarm Mode.

If you leave the watch in a setting mode (with ﬂ ashing digits) for two or three minutes without performing any operation, the watch will exit the setting mode automatically.

Initial Screens

When you enter the World Time or Alarm Mode, the data you were viewing when you last exited the mode appears ﬁ rst.

Scrolling

The B and D buttons are used in the setting mode to scroll through data. In most cases, holding down these buttons during a scroll operation scrolls through the data at high speed.

E-24

Mode Reference Guide

Your watch has “ﬁ ve modes”. The mode you should select depends on what you want to do.

To do this: Enter this mode: See:

View the current date in the Home City x Conﬁ gure Home City and daylight saving time (DST) x settings Conﬁ gure time and date settings x Switch between 12-hour and 24-hour timekeeping x Display an alarm countdown x

View the current time in one of 48 cities (31 time zones) around the globe

Use the stopwatch to measure elapsed time Stopwatch Mode E-39

Use the countdown timer Countdown Timer Mode E-42

Set an alarm time Alarm Mode E-45

Countdown Timer Mode

Timekeeping Mode E-25

World Time Mode E-36

Alarm ModeStopwatch Mode

Timekeeping

Minutes

Hour

Day of week

Seconds

Month Day

Use the Timekeeping Mode to set and view the current time and date.

If you have an alarm time set, the right digital dial will

change to show a countdown of the ﬁ nal 60 minutes until the alarm time is reached. When viewing a digital dial, you can move the analog

hands for an unobstructed view.

x A to toggle the left digital dial between month/

Press day and hour/minutes.

E-21

E-23

E-25

Conﬁ guring Home City Settings

There are two Home City settings: actually selecting the Home City, and selecting either standard time or daylight saving time (DST).

City code

For details about city codes, see the “City Code Table” at the back of this

manual. Whenever you enter a setting mode, the analog hands will automatically move to x positions that allow easier viewing of the digital dials.

E-26

After the setting is the way you want, press 5. A to return to the Timekeeping Mode.

The

x DST indicator appears to indicate that Daylight Saving Time is turned on.

Exiting a setting mode will normally cause the hands to return to regular

timekeeping automatically. However, if you manually move the hands (page E-61) and then enter a setting mode, they will not return to regular timekeeping automatically when you exit the setting mode. In this case, you will need to return the hands to their normal positions manually (page E-62).

Note

After you specify a city code, the watch will use UTC* offsets in the World Time x Mode to calculate the current time for other time zones based on the current time in your Home City.

Coordinated Universal Time, the world-wide scientiﬁ c standard of timekeeping.

The reference point for UTC is Greenwich, England.

E-28

To conﬁ gure Home City settings

In the Timekeeping Mode, hold down 1. A for about two seconds until ADJ appears in the right digital dial. When you release A, the city code and city name will scroll across the right digital dial. This is the setting mode.

The watch will exit the setting mode automatically if

you do not perform any operation for about two or three minutes.

DST indicator

To change the Daylight Saving Time (summer time) setting

DST indicator

Use 2. D (East) and B (West) to scroll through the city codes in the right digital dial until the one you want to use as your Home City is displayed.

Press 3. C so the DST indicator is ﬂ ashing in the left digital dial, which indicates the DST setting mode.

Press 4. D to toggle the DST setting between Daylight Saving Time (ON) and Standard Time (OFF) in the right digital dial.

Note that you cannot switch between standard time and daylight saving time (DST) while UTC is selected as your Home City.

Whenever you enter a setting mode, the analog hands

will automatically move to positions that allow easier viewing of the digital dials. This is the setting mode.

Press 2. C to enter the DST setting mode. Press 3. D to toggle the DST setting between Daylight

Saving Time (ON) and Standard Time (OFF).

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Operation Guide 5231

After the setting is the way you want, press 4. A to return to the Timekeeping Mode.

The

x DST indicator appears to indicate that Daylight Saving Time is turned on.

Exiting a setting mode will normally cause the hands to return to regular x timekeeping automatically. However, if you manually move the hands (page E-61) and then enter a setting mode, they will not return to regular timekeeping automatically when you exit the setting mode. In this case, you will need to return the hands to their normal positions manually (page E-62).

E-30

Press 2. C to move the ﬂ ashing in the sequence shown below to select the other settings.

City Code

Power Saving Minute

Illumination

Duration

DST

Button Operation

Tone On/Off

12/24-Hour Format

Day

Seconds

Month

Hour

Year

The following steps explain how to conﬁ gure timekeeping settings only. x

E-32

Press 4. A to exit the setting mode.

The watch automatically adjusts its analog setting to match the current time

displayed in the left digital dial. Exiting a setting mode will normally cause the hands to return to regular x timekeeping automatically. However, if you manually move the hands (page E-61) and then enter a setting mode, they will not return to regular timekeeping automatically when you exit the setting mode. In this case, you will need to return the hands to their normal positions manually (page E-62).

Note

For information about selecting a Home City and conﬁ guring the DST setting, see

“Conﬁ guring Home City Settings” (page E-26). While 12-hour format is selected for timekeeping, a x PM indicator will appear for times from noon to 11:59 p.m. No indicator appears for times from midnight to 11:59 a.m. With 24-hour format, time is displayed from 0:00 to 23:59, without any

PM indicator.

Conﬁ guring Current Time and Date Settings

You can conﬁ gure current time and date settings.

To change the current time and date settings

City code

When the timekeeping setting you want to change is ﬂ ashing, use 3. D and/or B to change it as described below.

Screen To do this: Do this:

Change the city code

The watch’s built-in full automatic calendar makes allowances for different month x lengths and leap years. Once you set the date, there should be no reason to change it except after you have the watch’s rechargeable battery replaced or after power drops to Level 5 (page E-15). The day of the week changes automatically when the date changes.

Refer to the pages shown below for more information on Timekeeping Mode x settings.

Button operation tone on/off: “To turn the button operation tone on and off”

−

(page E-63) Enabling and disabling power saving: “To turn Power Saving on and off” (page

−

E-65) The illumination duration: “To change the illumination duration” (page E-51)

−

Toggle between Daylight Saving Time (ON) and Standard Time (OFF)

Toggle between 12-hour (12H) and 24-hour (24H) timekeeping

Reset the seconds to 00

Change the hour or minute

Change the year, month, or day

Toggle between button operation tone on (KEY

Toggle the illumination duration between three seconds (LT3) and 1.5 seconds (LT1)

Whenever you enter a setting mode, the analog hands

will automatically move to positions that allow easier viewing of the digital dials.

Use D (East) and B (West).

Press D.

Use D (+) and B (–).

) and off (MUTE)

Press D.

E-31

E-33

E-34

Using the World Time Mode

Currently selected World Time City

Current time in the currently selected World Time City

E-36

The standard time/daylight saving time (DST) setting affects only the currently x selected time zone. Other time zones are not affected.

To swap your Home Time and World Time Cities

In the World Time Mode, use 1. D to select the city you want to use as your new Home City.

To swap, hold down 2. A and B at the same time until the watch beeps.

This will make the World Time City you selected in step 1 ( x NYC (New York)) your new Home City.

x TYO (Tokyo)) will be your new World Time City.

Your previous Home City (

E-38

You can use the World Time Mode to view the current time in one of 31 time zones (48 cities) around the globe. The city that is currently selected in the World Time Mode is called the “World Time City”.

To enter the World Time Mode

Use C to select the World Time Mode as shown on page E-22.

The right digital dial will show

x WT for about one second.

After that, the city code and city name will scroll once across the right digital dial, and then the three-letter corresponding city code will be displayed.

To view the time in another time zone

In the World Time Mode, use D (East) to scroll through city codes.

A and B

To specify standard time or daylight saving time (DST) for a city

DST indicator

Using the World Time Mode to change the DST setting of the city code that is

selected as your Home City also will change the Timekeeping Mode time DST setting. Note that you cannot switch between standard time/daylight saving time (DST)

while UTC is selected as the World Time City.

In the World Time Mode, use 1. D (East) and B (West) to scroll through the city codes in the right digital dial until the one whose Standard Time/Daylight Saving Time setting you want to change is displayed.

Hold down 2. A for about two seconds until the watch beeps.

This toggles the city code you selected in step 1

between Daylight Saving Time (DST indicator displayed in the left digital dial) and standard time (DST indicator not displayed).

Using the Stopwatch

The stopwatch measures elapsed time, split times, and two ﬁ nishes.

Minutes Seconds

1/100 second

To enter the Stopwatch Mode

Use C to select the Stopwatch Mode (STW) as shown on page E-23.

E-35

E-37

E-39

Operation Guide 5231

To perform an elapsed time operation

D D D D A

Start Stop (Restart) (Stop) Reset

To pause at a split time

Start Split

To measure two ﬁ nishes

Start Split

E-40

A A D A

(SPL displayed)

A D A A

(SPL displayed) First runner ﬁ nishes. Display time of ﬁ rst runner.

Split release Stop Reset

Stop

Second runner ﬁ nishes.

Split release

Display time of second runner.

Reset

Using the Countdown Timer

The countdown timer can be set within a range of one minute to 100 minutes. An alarm sounds when the countdown reaches zero.

Countdown time (Minutes, seconds)

E-42

To perform a countdown timer operation

Start Stop (Restart) (Stop) Reset

Before starting a countdown timer operation, check to make sure that a x countdown operation is not in progress (indicated by the seconds counting down). If it is, press D to stop it and then A to reset to the countdown start time. An alarm sounds for 10 seconds when the end of the countdown is reached. This

alarm will sound in all modes. The countdown time is reset to its starting value automatically when the alarm sounds.

To stop the alarm

Press any button.

E-44

To enter the Countdown Timer Mode

Use C to select the Countdown Timer Mode (TMR) as shown on page E-23.

To specify the countdown start time

Enter the Countdown Timer Mode.1.

If a countdown is in progress (indicated by the

seconds counting down in the left digital dial), press D to stop it and then press A to reset to the current countdown start time. If a countdown is paused, press x A to reset to the current countdown start time.

D D D A

Note

The Stopwatch Mode can indicate elapsed time up to 59 minutes, 59.99 seconds. Once started, stopwatch timing continues until you press x D to stop it, even if you exit the Stopwatch Mode to another mode and even if timing reaches the stopwatch limit deﬁ ned above. Exiting the Stopwatch Mode while a split time is frozen on the display clears the

split time and returns to elapsed time measurement.

Hold down 2. A until the minute setting of the current countdown start time starts to ﬂ ash. This is the setting mode.

Whenever you enter a setting mode, the analog hands will automatically move to

positions that allow easier viewing of the digital dials.

Press 3. C to move the ﬂ ashing between the minute and second settings. Use 4. D (+) and B (–) to change the ﬂ ashing item.

x 00'00".

To set the starting value of the countdown time to 100 minutes, set

Press 5. A to exit the setting mode.

Exiting a setting mode will normally cause the hands to return to regular timekeeping automatically. However, if you manually move the hands (page E-61) and then enter a setting mode, they will not return to regular timekeeping automatically when you exit the setting mode. In this case, you will need to return the hands to their normal positions manually (page E-62).

Using the Alarm

Alarm number

Alarm time (Hour : Minutes)

You can set ﬁ ve independent daily alarms. When a daily alarm is turned on, an alarm tone will sound for about 10 seconds each day when the time in the Timekeeping Mode reaches the preset alarm time. This is true even if the watch is not in the Timekeeping Mode. You can also turn on an Hourly Time Signal, which will cause the watch to beep twice every hour on the hour.

To enter the Alarm Mode

Use C to select the Alarm Mode as shown on page E-23.

The right digital dial will show

x ALM for about one

second and then the indictor for the currently selected alarm (AL1 through AL5, or SIG) will appear. When you enter the Alarm Mode, the data you were

viewing when you last exited the mode appears ﬁ rst.

E-41

E-43

E-45

To set an alarm time

Alarm ON/OFF indicator

Hold down 2. A for about two seconds until the alarm time starts to ﬂ ash. This is the setting mode.

Whenever you enter the setting mode, the analog hands will automatically move

to positions that allow easier viewing of the digital dials.

Press 3. C to move the ﬂ ashing between the hour and minute settings.

E-46

To turn an alarm and the Hourly Time Signal on and off

Hourly Time Signal on indicator

To stop the alarm

Press any button.

E-48

In the Alarm Mode, use 1. D to scroll through the alarm indicators (AL1 to AL5, SIG) in the right digital dial until the one whose time you want to set is displayed.

DDDDD

AL1 AL3 AL5AL2 AL4 SIG

In the Alarm Mode, use 1. D to scroll through the alarm indicators (AL1 to AL5, SIG) in the right digital dial until the one you want is displayed.

When the alarm or the Hourly Time Signal you want is 2. selected, press A to toggle it between on and off.

The alarm on indicator (when any alarm is on) and the Hourly Time Signal on indicator (when the Hourly Time Signal is on) are displayed in all modes.

While a setting is ﬂ ashing, use 4. D (+) and B (–) to change it.

When setting the alarm time using the 12-hour format, take care to set the time x correctly as a.m. (no indicator) or p.m. (PM indicator).

Press 5. A to exit the setting mode.

To test the alarm

In the Alarm Mode, hold down D to sound the alarm.

Alarm Countdown

Alarm ON/OFF indicator

When you enter the Timekeeping Mode from another mode while an alarm

countdown is in progress, the day of the week will appear in the right digital dial for two seconds. After that, the countdown will appear. If an alarm countdown for another alarm starts while a previous alarm countdown is

already in progress, it will be displayed after the ongoing countdown reaches zero and its alarm sounds.

When the current time reaches one hour before an alarm time setting, the alarm on/off indicator (in the lower digital dial) will ﬂ ash and a countdown of the ﬁ nal 60 minutes will be displayed in the right digital dial while the watch is in the Timekeeping Mode.

Note

Pressing

x A while an alarm countdown is in progress

will display the day of the week in the right digital dial for about two seconds. After that, the dial will return to the countdown.

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E-49

Operation Guide 5231

Illumination

The face of the watch is illuminated for easy reading in the dark. The watch’s auto light switch turns on illumination automatically when you angle the watch towards your face.

The auto light switch must be turned on (page E-54) for

it to operate.

To turn on illumination manually

Press B in any mode to illuminate the face of the watch.

You can use the procedure below to select either x

1.5 seconds or three seconds as the illumination duration. When you press B, the face will remain illuminated for about 1.5 seconds or three seconds, depending on the current illumination duration setting.

E-50

After all of the settings are the way you want, press 4. A to exit the setting mode.

About the Auto Light Switch

Turning on the auto light switch causes illumination to turn on, whenever you position your wrist as described below in any mode.

Moving the watch to a position that is parallel to the ground and then tilting it towards you more than 40 degrees causes illumination to turn on.

E-52

To turn the auto light switch on and off

Auto light switch on indicator

Illumination Precautions

LED panel that provides illumination loses power after very long use.

Illumination may be hard to see when viewed under direct sunlight. x Illumination turns off automatically whenever an alarm sounds. x Frequent use of illumination runs down the battery. x

E-54

In the Timekeeping Mode, hold down B for about three seconds to toggle the auto light switch on (indicator displayed in the right digital dial) and off (indicator not displayed).

The auto light switch on indicator appears in all

modes while the auto light switch is turned on. The auto light switch turns off automatically whenever x battery power drops to Level 4 (page E-15).

More than 40°

Wear the watch on the outside of your wrist

The above operation turns on illumination regardless of the current auto light switch x setting.

To change the illumination duration

Whenever you enter a setting mode, the analog hands will automatically move to

positions that allow easier viewing of the digital dials.

Use 2. C to cycle through the settings in the right digital dial until the current illumination duration (LT1 or LT3) is shown.

See the sequence in step 2 of the procedure under “To change the current time and date settings” (page E-31) for information about how to scroll through setting mode.

Press 3. D to toggle the illumination duration between three seconds (LT3 displayed) and 1.5 seconds (LT1 displayed).

Warning!

Always make sure you are in a safe place whenever you are reading the face of the watch using the auto light switch. Be especially careful when running or engaged in any other activity that can result in accident or injury. Also take care that sudden illumination by the auto light switch does not startle or distract others around you. When you are wearing the watch, make sure that its auto light switch is

turned off before riding on a bicycle or operating a motorcycle or any other motor vehicle. Sudden and unintended operation of the auto light switch can create a distraction, which can result in a trafﬁ c accident and serious personal injury.

Note

This watch features a “LED”, so the auto light switch operates only when available

light is below a certain level. It does not illuminate the face under bright light.

Auto light switch precautions

Wearing the watch on the inside of your wrist, movement of your arm, or vibration x of your arm can cause frequent activation of the auto light switch and illumination of the face. To avoid running down the battery, turn off the auto light switch whenever engaging in activities that might cause frequent illumination of the face. Note that wearing the watch under your sleeve while the auto light switch is turned

on can cause frequent illumination of the face and can run down the battery.

Illumination may not turn on if the face of the watch is more than 15 degrees above or below parallel. Make sure that the back of your hand is parallel to the ground. Illumination turns off after the preset illumination duration (page

E-51), even if you keep the watch pointed towards your face. Static electricity or magnetic force can interfere with proper x operation of the auto light switch. If illumination does not turn on, try moving the watch back to the starting position (parallel with the ground) and then tilt it back towards your face again. If this does not work, drop your arm all the way down so it hangs at your side, and then bring it back up again.

E-51

E-53

E-55

You may notice a very faint clicking sound coming from the watch when it is x shaken back and forth. This sound is caused by mechanical operation of the auto light switch, and does not indicate a problem with the watch.

E-56

The watch will return to regular timekeeping automatically if you do not perform x any operation for about two or three minutes. Any changes you have made to settings up to that point will be saved. If the hour and minute hands are all at 12 o’clock, which is their home position, jump to step 3.

Use 2. D (+) and B (–) to adjust the hour and minute hand positions.

Holding down either button will cause the hand to move at high speed. Once started, high-speed hand movement will continue even if you release the button. To stop high-speed hand movement, press any button. High-speed hand movement started with the

x D (+) button will stop

automatically after 12 revolutions of the minute hand. If started with the B (–) button, it will stop after one revolution of the minute hand.

Press 3. A to exit home position correction and return to regular timekeeping.

E-58

Hand Home Position Adjustment

Strong magnetism or impact can cause the hands of the watch to be off.

Home position adjustment is not necessary when the analog time and digital time x are the same time in the Timekeeping Mode.

To adjust home positions manually

In the Timekeeping Mode, hold down 1. A and keep it depressed for about ﬁ ve seconds until H.SET appears in the right digital dial.

The hour and minute hands should all move to 12 o’clock, which is their home position. Though

x ADJ will appear in the right digital dial about two seconds after you hold

down A, do not release the button yet. Keep it depressed until H.SET appears. When H.SET appears in the right digital dial, release the A button. This will cause the hour and minute hands to move to 12 o’clock.

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Note

After performing home position adjustment, enter the Timekeeping Mode and check to make sure that the analog hands and the digital dial indicate the same time. If they do not, perform home position adjustment again.

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Operation Guide 5231

Moving the Hands for Easy Viewing of the Digital Dials

You can use the procedure below to move the analog hands in order to better view a digital dial.

Note

The analog hands will not move while battery power is low. x

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To return the hands to their normal positions

Hold down C for about two seconds until HAND appears.

Note

The hands will also return to their normal positions if you do not perform any operation for about one hour. The hands also will move away from the digital dial automatically whenever you x enter a setting mode in the Timekeeping Mode, Timer Mode, or Alarm Mode. Hold down x C for about four seconds to return the hands to their normal positions and switch to the Timekeeping Mode.

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Use 2. C to cycle through settings in the right digital dial until the current button operation tone (MUTE or KEY

See the sequence in step 2 of the procedure under “To change the current x time and date settings” (page E-31) for information about how to scroll between settings.

Press 3. D to toggle the button operation tone on (KEY After all of the settings are the way you want, press 4. A to exit the setting mode.

Note

The mute indicator is displayed in all modes when the button operation tone is

turned off.

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) is displayed.

) and off (MUTE).

To move the hands to view a digital dial

Hold down C for about two seconds until HAND appears. Releasing C will cause the HANDS indicator to ﬂ ash and the hands will move away from the digital dial.

Hold down C.

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Other Settings

The button operation tone sounds any time you press one of the watch’s buttons. You can turn the button operation tone on or off as desired.

Even if you turn off the button operation tone, the alarm, Hourly Time Signal, and

Countdown Timer Mode alarm all operate normally.

To turn the button operation tone on and off

Mute indicator

To turn Power Saving on and off

Power saving on indicator

Use 2. C to cycle through the settings in the right digital dial unit the current power saving setting (PSON or PSOF) is displayed.

See the sequence in step 2 of the procedure under “To change the current time and date settings” (page E-31) for information about how to scroll between settings.

Press 3. D to toggle Power Saving on (PSON) and off (PSOF).

Whenever you enter a setting mode, the analog hands

will automatically move to positions that allow easier viewing of the digital dials.

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Whenever you enter a setting mode, the analog hands

will automatically move to positions that allow easier viewing of the digital dials.

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After all of settings are the way you want, press 4. A to exit the setting mode.

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The analog hands are not indicating the correct time.■

If the HANDS indicator is displayed on the right digital dial, it means that the analog hands have been moved for easier viewing of the digital dials. Hold down C for about four seconds to return to the Timekeeping Mode.

World Time Mode

The time for my World Time City is off in the World Time Mode.■

This could be due to incorrect switching between standard time and daylight saving time. See “To specify standard time or daylight saving time (DST) for a city” (page E-37) for more information.

Charging

The watch does not resume operation after I expose it to light.■

This can happen after the power level drops to Level 5 (page E-15). Continue exposing the watch to light until the battery power indicator shows H or M.

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Troubleshooting

Time Setting

The current time setting is off by hours.■

Your Home City setting may be wrong (page E-26). Check your Home City setting and correct it, if necessary.

The current time setting is off by one hour.■

You may need to change your Home City’s standard time/daylight saving time (DST) setting. Use the procedure under “To change the current time and date settings” (page E-31) to change the standard time/daylight saving time (DST) setting.

The hands are off.■

This could indicate that the watch has been exposed to magnetism or strong impact, which has caused problems with proper hand alignment. Adjust the watch’s hand home position alignment (page E-57).

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Speciﬁ cations

Accuracy at normal temperature: ±15 seconds a month Timekeeping: Hour, minutes, seconds, p.m. (PM), year, month, day, day of the

Time format: 12-hour and 24-hour Calendar system: Full Auto-calendar pre-programmed from the year 2000 to

Other: Home City code (can be assigned one of 48 city codes); Standard Time/

World Time: 48 cities (31 time zones)

Other: Daylight Saving Time/Standard Time

Stopwatch:

Measuring unit: 1/100 second Measuring capacity: 59' 59.99" Measuring modes: Elapsed time, split time, two ﬁ nishes

week, alarm countdown

2099

Daylight Saving Time (summer time)

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Operation Guide 5231

Countdown Timer:

Measuring unit: 1 second Countdown range: 100 minutes Countdown start time setting range: 1 to 100 minutes (1-second increments)

Alarms: 5 Daily alarms; Hourly Time Signal Illumination: LED; Selectable illumination duration Other: Battery power indicator; Power Saving; Button operation tone on/off Power Supply: Solar panel and one rechargeable battery

Approximate battery operating time: 8 months (from full charge to Level 4) under the following conditions:

Watch not exposed to light

Internal timekeeping x Display on 18 hours per day, sleep state 6 hours per day x 1 illumination operation (1.5 seconds) per day x 10 seconds of alarm operation per day x 1 hand movement for easy viewing of the digital dials per day x

Frequent use of illumination runs down the battery.

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City Code Table

L-1

City Code Table

City

Code

L-2

City

PPG Pago Pago –11 HNL Honolulu –10 ANC Anchorage –9

YVR Vancouver LAX Los Angeles

YEA Edmonton DEN Denver MEX Mexico City

CHI Chicago NYC New York –5

SCL Santiago

YHZ Halifax YYT St. Johns –3.5

RIO Rio De Janeiro –3

Fernando De Noronha

FEN

UTC Offset/

GMT Differential

City

Code

–8

–7

–6

–4

–2

ROM Rome

MOW Moscow

City

RAI Praia –1

UTC

LON London MAD Madrid PAR Paris

BER Berlin STO Stockholm

ATH Athens

JRS Jerusalem

JED Jeddah THR Tehran +3.5

UTC Offset/

GMT Differential

0LIS Lisbon

+2CAI Cairo

Code

City

DXB Dubai +4

KBL Kabul +4.5 KHI Karachi +5

DEL Delhi +5.5 KTM Kathmandu +5.75 DAC Dhaka +6 RGN Yangon +6.5 BKK Bangkok +7

SIN Singapore HKG Hong Kong

BJS Beijing

TPE Taipei

SEL Seoul

TYO Tokyo ADL Adelaide +9.5

UTC Offset/

GMT Differential

City

Code

GUM Guam

SYD Sydney NOU Noumea +11 WLG Wellington +12

xBased on data as of December 2010.

x



The rules governing global times

(UTC offset and GMT differential) and

summer time are determined by each

individual country.

UTC Offset/

GMT Differential

+10

L-3

Casio 5231 Operation Guide

Specifications and Main Features

Frequently Asked Questions

User Manual