Casio DBC-30, DBC-30G, DBC-300A, DBC-300GA User Manual

Important Information

Battery

When you first notice signs of insufficient power (e.g., dim display or illegible display), the battery should be replaced by a CASIO dealer or distributor. The battery included in your watch is a factory-installed test battery, so its service life may be shorter than that of a standard battery.

Water Resistance

Watches are classified by water resistance grades (from Grade I to Grade V) according to their water resistance capabilities. Refer to the table below to determine the correct usage for your watch.

Notes:

• Grade I: Not water resistant. Avoid all contact with moisture.
• Grade III: Do not press buttons underwater.
• Grade IV: Buttons can be pressed underwater once, but not repeatedly. If the watch is exposed to saltwater, rinse it thoroughly and dry it.
• Grade V: Suitable for scuba diving (except for depths requiring a helium-oxygen gas mixture).

Some water-resistant watches have leather straps. Do not wear these models while swimming or engaging in any other activity that may expose the strap to water.

Care for Your Watch

• Never attempt to open the case or remove the back cover yourself.
• The rubber gasket that protects the watch from water and dust should be replaced every 2-3 years.
• If moisture gets inside the watch, have it checked immediately by a CASIO dealer or distributor.
• Do not expose the watch to extreme temperatures.
• While the watch is designed for normal use, avoid rough handling and do not drop it.
• Do not fasten the strap too tightly. You should be able to fit a finger between your wrist and the strap.
• Clean the watch and strap using a dry, soft cloth, or a soft cloth dampened with a mild solution of neutral detergent and water. Never use volatile solvents (e.g., benzine, thinners, spray cleaners, etc.).
• When not in use, store your watch in a dry place.
• Avoid exposing the watch to gasoline, cleaning solvents, aerosol sprays, adhesives, paints, etc. Chemical reactions caused by these materials can damage gaskets, the case, and the watch's finish.
• Some models have silk-screened designs on their straps. Be careful when cleaning these straps to avoid damaging the designs.

For watches with plastic straps

You may notice a white powdery substance on the strap. This substance is harmless to your skin or clothing and can be easily removed by wiping with a cloth. Exposure of the plastic strap to perspiration or moisture, or storing it in a humid environment, can cause damage, tearing, or cracking of the strap. To ensure a long service life for the plastic strap, wipe it clean of dirt and moisture with a soft cloth whenever possible.

For watches with fluorescent cases and straps

Prolonged exposure to direct sunlight may cause the fluorescent color to gradually fade. Prolonged contact with moisture may also cause the fluorescent color to gradually fade. If any moisture gets on the watch surface, wipe it off as soon as possible. Prolonged contact with any other wet surface may cause discoloration of the fluorescent color. Ensure the fluorescent surface is dry and avoid contact with other surfaces.

Product Information

Technical Specifications

• Timekeeping Accuracy: ±15 seconds per month under normal temperature conditions.
• Timekeeping Mode: Hours, minutes, seconds, AM/PM indicator (A/P), year, month, day, day of week.
• 12/24-Hour Format: Timekeeping can be switched between 12-hour and 24-hour formats.
• Calendar System: Auto-calendar, programmed from the year 1990 to 2089.

Phonebook Mode

• Name, Telephone Number, Fax Number.
• Memory Capacity: Up to 30 sets of data, each consisting of up to 8 characters for the name and up to 12 digits for the number.
• Other Features: Automatic sorting and sequential data search.

Calculator Mode

• 8 digits (7 digits for negative numbers).
• Calculations: Four basic arithmetic operations, sequential and mixed calculations, calculations with constants for +/-, x/÷, and memory calculations.
• Other Features: Enable/disable confirmation beep.

Alarm Mode

• Multifunction alarm, 5 daily alarms, hourly time signal.

Stopwatch Mode

• Measuring Range: 23 hours, 59 minutes, 59.99 seconds.
• Measurement Accuracy: One hundredth of a second.
• Measurement Modes: Lap times, split times, 1st and 2nd place times.
• Other Features: Backlight function (flashes with alarm and hourly time signals).

Power

• One lithium battery (CR-2016 type).
• Battery Life: Approximately 2 years for CR-2016 battery (based on 20 seconds of alarm usage and 2 seconds of backlight usage per day). The table below shows how backlight usage affects the estimated battery life: 5 times per day: Approx. 21 months; 10 times per day: Approx. 13 months.

Important Note: All data stored in memory will be erased in the following cases: 1. Insufficient battery power. 2. Battery replacement. 3. Repair. It is recommended to keep paper copies of your stored data to prevent loss.

General Description of Operating Modes

Use button "B" to cycle through the different modes. Detailed descriptions of each mode's operation are provided below.

Timekeeping Mode

Illustration of the Timekeeping Mode screen showing day of week, date, year, and time with AM/PM indicator. Buttons labeled 'A', 'B', 'C', 'D' are shown.

Phonebook Mode

Illustration of the Phonebook Mode screen displaying a name and phone number. Buttons labeled 'TEL', 'FAX', 'STEL', 'C', 'B', 'D', 'A' are shown.

Calculator Mode

Illustration of the Calculator Mode screen showing numerical input and operation symbols. Buttons labeled 'CAL', 'C', 'D', 'A', 'B' are shown.

Alarm Mode

Illustration of the Alarm Mode screen showing alarm settings, including month, day, hour, minute, and alarm number.

Stopwatch Mode

Illustration of the Stopwatch Mode screen showing elapsed time (0:00'00") with buttons labeled 'STOP-W', 'A', 'B', 'C', 'D'.

How to Set Current Time and Date

1. In Timekeeping Mode, press and hold button "A" until the seconds digits on the display start flashing. Flashing seconds digits indicate that the value can be changed.
2. Press button "B" or "D" to move the flashing digit to the next position in the sequence shown below. Holding either button allows for faster scrolling.
3. While the seconds digits are flashing (and can be changed), press button "C" to reset them to "00". If you press "C" when the seconds value is between "30" and "59", the minutes value will be incremented by one. If the seconds value is between "00" and "29", the minutes value remains unchanged.
4. While digits in other positions (except seconds) are flashing (and can be changed), you can enter the desired digits using the numeric buttons.
• If you are using the 12-hour format, an "A" (AM) or "P" (PM) indicator will flash along with the hour or minute digits. Press button "PM" to switch between AM and PM.
• The date can be set from January 1, 1990, to December 31, 2089. Entering digits 90-99 for the year sets the corresponding year in the range 1990-1999, while entering 00-89 sets the corresponding year in the range 2000-2089.
5. After setting the current time and date, press button "A" to return to Timekeeping Mode.
6. The day of the week is set automatically according to the date.
7. If you do not press any button for several minutes while digits are flashing, the flashing will stop, and the watch will automatically return to Timekeeping Mode.

Backlight

If the backlight function is enabled, the watch display will flash when an alarm sounds. For more information on alarm sounds, refer to the "Alarm Mode" section. The backlight uses an electro-luminescent light source that may gradually lose its luminescence with prolonged use.

How to Enable and Disable the Backlight Function

In Timekeeping Mode, press and hold button "C" for one or two seconds to enable or disable the backlight function. An illustration shows the backlight indicator on the display and the 'C' button being pressed to enable/disable it. The backlight indicator remains displayed in all modes. Pressing button "D" in any mode will illuminate the display for approximately two seconds, regardless of whether the backlight function is enabled. The watch emits a sound when the backlight is activated. This is normal and does not indicate a malfunction.

Phonebook Operations

Saving Data

The Phonebook Mode allows you to store up to 30 sets of data. Each set includes a name and a phone or fax number. Each name can be up to 8 characters, and each number up to 12 digits. Stored data is automatically sorted alphabetically by name. You can view the stored and sorted data.

Switching Between Phone Numbers and Fax Numbers

Illustration showing how to switch between phone number and fax number screens using the 'C' button. The screen displays 'TEL' for phone numbers and 'FAX' for fax numbers. When you enter Phonebook Mode, the last accessed phone number or fax number is displayed. Pressing 'C' switches between the phone number and fax number associated with the same name. If data for the specified name is not available, a new data entry screen appears. Pressing 'C' after the new data entry screen appears displays the last accessed data.

Memory Usage

In Phonebook Mode (with either the phone number or fax number screen displayed), you can check the amount of memory used by pressing and holding the "=" button.

Viewing Phonebook Data

In Phonebook Mode (with either the phone number or fax number screen displayed), press button "+/-" or "M/-" for sequential forward viewing, or "MC" or "+/-" for sequential backward viewing. Holding either button allows for faster scrolling.

Entering New Data

1. In Phonebook Mode, display the phone number or fax number screen (depending on what you intend to enter).
2. Use button "MC" or "+/-" to display the new data entry screen. If no data is stored in the phonebook, the new data entry screen appears immediately upon entering Phonebook Mode.
3. Press button "A" to display the cursor.
4. Use button "B" or "D" to move the cursor to the character you wish to change.
5. Use the numeric buttons to input the desired characters. Each numeric button can input multiple characters; pressing the button cycles through them. For example, pressing button '1' cycles through 'U', 'V', '1'. Letters are shown above the number buttons. Use the "=" button for a space and the ".PM" button for a period. Use the "M-" button for a hyphen and the "X/MR" button for a colon. Be careful not to confuse the letter "O" with the digit "0". Entering "0" instead of "O" may affect automatic data sorting.
6. After the desired character is in position, press button "B" to move the cursor to the right.
7. Repeat steps 3 and 4 to enter the remaining characters. A name can contain up to 8 characters.
8. When the cursor is in the number field, you can enter the desired digits using the corresponding numeric buttons. The digit entered by each button is shown on the button itself. Use the "=" button for a space and the "M-" button for a hyphen. The cursor automatically moves to the right with each digit entered. A phone or fax number can contain up to 12 digits.
9. To enter another record, press button "MC" or "+/-" to display the new data entry screen, then repeat steps 4-7.
10. After entering the data, press button "A" to return to the original Phonebook Mode screen. The display will show "SORT" until all data is written to memory in alphabetical order. The watch then returns to the Phonebook Mode screen from which you started data entry. You cannot switch between phone number and fax number screens if the cursor is flashing. Press button "A" to return to the original Phonebook Mode screen first.

Illustration of the data entry screen with fields for name (up to 8 characters) and number (up to 12 digits).

Editing Data

1. In Phonebook Mode, display the phone number or fax number screen (depending on what you intend to edit).
2. Use button "MC" or "+/-" to display the record you wish to edit.
3. Press button "A" to display the cursor.
4. Use button "B" or "D" to move the cursor to the character you wish to change.
5. Enter the desired character.
6. Press button "A" to complete the data entry and return to the phone number or fax number screen from which you started.

Deleting Data

1. In Phonebook Mode, display the phone number or fax number screen (depending on what you intend to delete).
2. Use button "MC" or "+/-" to display the record you wish to delete.
3. Press button "A" to display the cursor.
4. Press and hold button "C" until "CLR" (Clear) appears on the display, accompanied by a beep. This indicates the selected record has been deleted.
5. Press button "A" to complete the operation and return to the phone number or fax number screen from which you started.

Alarm Operations

Alarm Sound Modes

You can set up to 5 independent alarms with specified hour, minute, month, and day. If the alarm function is enabled, alarms will sound at the set time for 20 seconds. Press any button (A, C, or D) to stop the alarm. If the hourly time signal is enabled, it will sound at the beginning of each hour.

How to Set Alarm Times

1. In Alarm Mode, press button "MC" or "M-" to select an alarm number.
2. After selecting the alarm number, press button "A". The hour digits will start flashing, indicating they can be changed.
3. Press button "B" or "D" to move the flashing digit to the next position in the sequence shown below.
4. Use the numeric buttons to set the alarm time. The cursor moves automatically to the right with each digit entered. You can also move the cursor using buttons "B" and "D".
5. The alarm time format (12-hour or 24-hour) matches the format set in Timekeeping Mode.
6. If you are using the 12-hour format, an "A" (AM) or "P" (PM) indicator will flash along with the hour or minute digits. Press button "PM" to switch between AM and PM. Be careful not to confuse AM and PM when setting the alarm time.
7. To set an alarm without a specific month (daily alarm), enter "-" in the month field. While the month digits are flashing, press and hold "M-" until "-" appears.
8. To set an alarm without a specific day (daily alarm), enter "--" in the day field. While the day digits are flashing, press and hold "M-" until "--" appears.
9. After setting the alarm time, press button "A" to return to Alarm Mode. The alarm setting is automatically enabled. If no button is pressed for several minutes while digits are flashing, the flashing will stop, and the watch will automatically return to Alarm Mode.

How to Enable and Disable Alarm and Hourly Time Signal Settings

In Alarm Mode, press button "MC" or "+/-" to select the alarm or hourly time signal. With the desired signal selected, press button "C" to enable or disable its setting. An indicator for the enabled alarm or hourly time signal will appear on the display. If any alarm is enabled, the alarm indicator remains displayed in all modes.

How to Check Alarm Sound

In Alarm Mode, press and hold button "C" to sound the alarm.

Stopwatch Operations

The stopwatch mode allows you to measure split times, lap times, and 1st and 2nd place times. The total measurement interval is limited to 23 hours, 59 minutes, and 59.99 seconds, with an accuracy of one hundredth of a second.

Measuring Split Times

Illustration showing the sequence for starting, stopping, and resetting the stopwatch for split times using buttons C and A.

Measuring Lap Times

Illustration showing the sequence for starting, splitting, and resetting the stopwatch for lap times using buttons C and A.

Split Times and 1st/2nd Place Times

Illustration showing the sequence for starting, splitting, stopping, and recording 1st and 2nd place times using buttons C and A.

Calculator Operations

In Calculator Mode, you can use the numeric buttons, arithmetic operation buttons, and other watch buttons to input data and display calculation results. If no button is pressed for 5 or 6 minutes in Calculator Mode, the watch will automatically return to Timekeeping Mode. After completing calculations, press button "B" to return to Timekeeping Mode.

Basic Arithmetic Calculations

An indicator (+, -, x, or ÷) appears on the display when you press the corresponding arithmetic operation button. If the result of a calculation exceeds 8 digits, an "E" (Error) indicator will appear. Press "C" to clear the error message and continue calculations. Press "C" twice to stop calculations and clear all data.

Constant Calculations

Enter the number you wish to use as a constant, then press one of the arithmetic operation buttons twice. The "K" indicator will appear, showing the calculator is ready for constant calculations. For example, to calculate 10 + 7, 7, 7, 7: Enter 7, press "+" twice, then enter 10, press "+", then 7, press "+", etc.

Memory Operations

M-: Subtracts the displayed value from the value stored in memory.
M+: Adds the displayed value to the value stored in memory.
MC: Clears the value stored in memory.
MR: Recalls the value stored in memory.
To perform a memory operation, press button "A" (which displays "S" on the screen), then press one of the memory buttons (M-, M+, MC, or MR). The "M" indicator appears on the display when there is data in memory.