CASIO WV-M400/M401 User Manual

Important Information

Battery

If you notice signs of low power (unclear display or no backlight), replace the battery at a CASIO dealer or distributor. The battery in your watch is installed by the manufacturer for testing purposes, so its service life may be shorter than a standard battery.

Water Resistance

Watches are classified by rating (from I to V) according to their water resistance. Check your watch's rating using the table below to determine usage rules.

Notes for respective sections:

• I: Watch is not water resistant. Avoid any moisture.
• III: If the watch is exposed to salt water, rinse thoroughly and dry.
• IV: If the watch is exposed to salt water, rinse thoroughly and dry.
• V: The watch can be used for scuba diving (except for depths requiring a helium-oxygen mixture).

ATTENTION!!! For all categories of watches, it is forbidden to:

• Press buttons underwater
• Move hands underwater
• Unscrew the crown underwater

Care of Your Watch

The rubber gasket that protects the watch from water and dust should be replaced every 2-3 years. If moisture enters the watch, have it checked immediately by a CASIO dealer or distributor. Do not expose the watch to extreme high or low temperatures. While the watch is designed for normal use, avoid rough handling and dropping it. Do not fasten the strap too tightly. A finger should fit between your wrist and the strap. To clean the watch and strap, use a dry soft cloth or a soft cloth dampened with a mild neutral detergent solution. Never use volatile agents (e.g., gasoline, solvents, spray cleaners, etc.). When not using your watch, store it in a dry place. Avoid contact with gasoline, cleaning solvents, spray aerosols, adhesives, paint, etc. Chemical reactions caused by these materials will damage gaskets, the case, and the watch's polish. Some models have screen-printed designs on their straps. Be careful when cleaning such straps to avoid damaging the designs.

For watches with resin straps...

You may notice a whitish powdery substance on the strap. This substance is not harmful to your skin or clothing and can be easily removed by wiping with a soft cloth. Exposure of the resin strap to sweat or moisture, or storing it in high humidity conditions, can lead to damage, tearing, or cracking of the strap. To ensure a long service life for the resin strap, wipe it clean of dirt and water with a soft cloth as often as possible.

For watches with fluorescent cases and straps...

Prolonged exposure to direct sunlight can cause the fluorescent color to gradually fade. Ensure there is no moisture on the fluorescent surface and avoid contact with other surfaces. Strong friction of a surface with fluorescent paint against another surface can transfer the fluorescent paint to that surface.

Disclaimer: CASIO COMPUTER CO., LTD. is not responsible for any damage that may occur from the use of this watch, and does not accept any claims from third parties.

General Description of Operating Modes

The figure shows the overall view of the watch in the Current Time Mode. Pressing Button C sequentially cycles through the modes: Current Time Mode → World Time Mode → Countdown Timer Mode → Stopwatch Mode → Alarm Mode → Calibration Mode → Current Time Mode. Press Button B to turn on the backlight in any mode.

World Time

In this mode, you can view the local time of any of the 48 cities in the world (29 time zones). World Time values are automatically set according to the current time.

DST (Daylight Saving Time) ON/OFF

In World Time Mode, select the city code for which you want to enable or disable Daylight Saving Time using Button D. Press and hold Button A to enable or disable Daylight Saving Time (DST).

Viewing Time in Another Time Zone

In World Time Mode, press Button D to select the city for which you want to view the time.

Calibration

This watch automatically corrects its time according to the calibration signal. However, you can also set the time manually. Before using the watch, set your current location's city code.

Setting Current Location City Code

1. In Current Time Mode, press and hold Button A until the city code indicator appears, indicating the start of settings.
2. Use Buttons B and D to change your current location's city code.
3. After setting, press Button A.

Calibration Signal

The watch receives the calibration signal and updates the time accordingly. Signal transmission centers are located in Germany (25 km from Frankfurt), Rugby (England), Fort Collins (USA), and Fukuoka/Fukushima (Japan). The signal is broadcast within a 1500 km radius. The signal may be weak at distances over 500 meters. The transmitted signal also depends on weather conditions, atmospheric pressure, and temperature. The signal may be weakened by the following factors:

• Being near a TV, computer, or household appliances.
• Being in a subway or tunnel.
• Being at an airport, train station, or high-speed road.
• Proximity to radio stations or signal transmitters.
• Electrostatic noise.

Two types of calibration signal reception:

Auto Calibration

When auto calibration is enabled, the watch automatically receives the signal five times a day and corrects the time. For selected cities (Moscow, Hong Kong, Honolulu, Beijing, Anchorage), auto calibration is enabled by default when set as the current location.

Manual Calibration

When manual calibration is enabled, you press a button yourself to receive the signal:

1. Place your watch horizontally.
2. In Current Time Mode, press and hold Button D for 2 seconds until a signal tone and the 'RC' indicator appear, indicating the start of signal reception.
3. Signal reception takes 2 to 7 minutes. Be careful not to move your watch during reception.
4. After signal reception, the watch display will show the last reception data and the 'GET' indicator.

To stop the reception process and return to Current Time Mode, press Button C. If signal reception fails, the watch display will show 'ERR' for 1-2 minutes. The watch will then automatically return to Current Time Mode. You can return to Current Time Mode by pressing Button C.

Auto Calibration Signal

When the auto calibration signal is enabled, the watch automatically receives the signal five times (during the night and early morning). Auto calibration only occurs when the watch is in Current Time Mode. Signal reception takes 2 to 7 minutes. Be careful not to move your watch during reception.

Enabling/Disabling Auto Calibration Signal

1. In Calibration Mode, press Button A to display the auto-signal ON/OFF indicator.
2. Use Button D to switch between 'ON' and 'OFF' for the auto-calibration signal.
3. After setting, press Button A.

Viewing Last Calibration Signal Data

When entering the Signal Reception Mode, the display shows the last reception data. The '-:--' indicator means that recent signal receptions have been unsuccessful. To return to Current Time Mode, press Button C.

Signal Reception Indicator

This indicator shows the signal reception strength (0 – L1 – L2 – L3). Try to position your watch for optimal signal reception whenever possible. It takes about 10 seconds for the watch to establish the signal reception strength shown on the indicator. If the calibration indicator is not displayed, signal reception is not occurring. Perform manual calibration or check your watch's settings.

Countdown Timer Mode

The countdown timer can be set from 1 minute to 24 hours. When the countdown reaches zero, an alarm sounds.

Setting Timer Modes

1. In Timer Mode, when the starting time is displayed, press and hold Button A. The starting time display will flash.
2. Press Button C to cycle through the settings: Hours → Minutes → Auto-repeat Mode → Hours.
3. Use Buttons D and B to enter the starting time values. To set a starting time of 24 hours, enter '0:00'.
4. Use Button D to enable ('ON') or disable ('OFF') the alarm sound.
5. Use Button D to enable or disable auto-repeat.
6. After setting, press Button A.

Using the Timer

Press Button D in Timer Mode to start the countdown. Press Button D again to stop the countdown. You can resume the countdown by pressing Button D. After stopping the countdown, you can press Button A to reset the countdown time to the starting value. When the countdown reaches zero, a 10-second alarm sounds, which can be stopped by pressing any button. The timer will then automatically reset to the starting time.

Stopwatch Mode

The Stopwatch Mode allows you to measure elapsed time, split times, and dual finishes. The maximum measurement range is 23 hours, 59 minutes, 59.99 seconds.

Modes of Measurement:

• a) Measuring Split Times: D (Start) – D (Stop) – D (Restart) – D (Stop) – A (Reset)
• b) Measuring with Split Times: D (Start) – A (Split Time) (The display shows "SPL") – A (Continue) – D (Stop) – A (Reset)
• c) Dual Finish: D (Start) – B (Split. First Finish) – D (Second Finish. Display shows 1st finish time) – A (Cancel Split. Display shows 2nd finish time) – A (Reset)

Alarm Mode

You can set a daily alarm that sounds for 10 seconds at the set time. If the hourly chime is enabled, a short beep sounds at the top of each hour.

Setting the Alarm

1. In Alarm Mode, press and hold Button A. The hour digits will flash, indicating they are selected for setting. The alarm is automatically enabled at this point.
2. Press Button C to cycle through the settings: Hours → Minutes → Hours.
3. Press Button D to increase and Button B to decrease the selected value. Holding down a button allows for faster adjustment. The 12-hour or 24-hour format corresponds to the format you selected when setting the current time.

Alarm Sound Check

In Alarm Mode, press Button D to check the alarm sound.

Enabling/Disabling Alarm Sound

In Alarm Mode, press Button D to cycle through the settings: All On – All Off – Daily Alarm Only – Hourly Chime Only. When the daily alarm is selected, the display shows 'ALM'. When the hourly chime is selected, the display shows 'SIG'.

Power Supply

This watch is equipped with a solar cell and a battery powered by the solar cell. If your watch is kept away from light for extended periods, the rechargeable battery's charge will decrease.

Battery Power Indicator

The battery power indicator is located at the top of the display.

If the indicator is not displayed, the battery is completely discharged. Place your watch in a well-lit area. Be careful not to expose your watch to direct sunlight for extended periods, as this may cause malfunctions. If you frequently use the backlight or alarm sounds, the 'RECOV' indicator may appear on the display, indicating battery recharging.

Charging the Battery

After a full charge, normal watch operation lasts for 9 months under the following conditions: Watch is not exposed to sunlight, 10 minutes of calibration per day, using the backlight for 1.5 seconds per day, using the alarm sound for 10 seconds per day, 18 hours of operation, 6 hours (per day) in sleep mode. Exposing your watch to sunlight daily will ensure continuous battery recharging:

The following table shows the time required to charge the battery:

Power Saving Mode

Sleep mode allows the watch to conserve battery power when kept in darkness. The following table shows the availability of watch functions when in sleep mode:

Enabling/Disabling Power Saving Mode

1. In Current Time Mode, press and hold Button A until the city code indicator flashes.
2. Press Button C 9 times to advance to the Power Saving Mode.
3. Press Button D to enable ('ON') or disable ('OFF') the power saving mode.
4. After setting, press Button A.

When the mode is enabled, the display shows 'PS'. Your watch may also automatically enter sleep mode. To return the watch to normal operation, place it in a well-lit area or press any button.

Current Time Mode

In Current Time Mode, press Button D to switch between the current time display and the dual time display (current time in another city). In this mode, you can view and set the time for your current location city and another city. The times in both cities are synchronized, so any changes to one will affect the other.

Before setting the time, ensure the watch displays the time and city of your current location. Press and hold Button A until the city code indicator appears. Press Button C to cycle through the settings: City Code → DST Mode → 12/24 Hour Format → Seconds → Hours → Minutes → Year → Month → Day → Power Saving Mode. If you select seconds for correction (seconds display flashes), press Button D to reset the seconds to 00. If you press Button D when the seconds are between 30 and 59, the seconds will reset to 00 and 1 will be added to the minutes. If the seconds are between 00 and 29, the minutes will not change. Use Buttons B and D to change the minutes and other values. Press Button D to select the 12/24 hour format. In the 12-hour format, 'P' indicates PM. Press Button D to enable/disable Daylight Saving Time. Each press cycles through: Auto DST ('AT') – DST Off ('OFF') – DST On ('ON') – Auto DST ('AT'). Auto DST is not available for all cities. Press Button D to enable ('ON') or disable ('OFF') the power saving mode. Use Buttons B and D to select your current location's city code. Holding down a button allows for faster adjustment. The day of the week is automatically set according to the date. The date can be set from January 1, 2000, to December 31, 2099. After setting the date and time, press Button A.

Backlight

Press Button B in any mode to turn on the backlight. The backlight uses an electroluminescent (EL) panel, whose brightness decreases with continuous use. When the display is illuminated, the watch emits an audible sound. This is due to the vibration of the backlight elements and is not a malfunction. The backlight is difficult to see if direct sunlight is falling on the watch. Frequent use of the backlight reduces battery life.

Button Sound ON/OFF

Press Button C in any mode to enable/disable button sounds.

Technical Specifications

Accuracy at normal temperature: ±15 seconds per month.

Current Time Mode: Hours, minutes, seconds, AM/PM, year, month, day, day of the week.

Calendar System: Auto calendar from 2000 to 2099.

Other: 12/24 hour format, DST (Daylight Saving Time).

Calibration Signal: Calibration signal (5 times daily), manual calibration, auto calibration, selection of transmission center.

Product Information

Product complies with GOST 26270-98 (cl. 4.35)

Certificate of Conformity No.: РОСС ЈР. АЯ46.Д42228 / РОСС ЈР. АЯ46.Д42071 / РОСС ЈР. АЯ46.Д42230