Casio Module 681 User Manual

Important Information

Battery

The battery in your watch is installed at the factory and should be replaced immediately upon the first signs of insufficient power (e.g., backlight not turning on, dim display) by an authorized CASIO dealer or distributor. The factory-installed battery is for testing purposes, and its service life may be shorter than specified in the technical characteristics.

Water Resistance

Watches are classified by water resistance rating (from I to V). Refer to the table below for proper usage and to determine your watch's rating.

Notes on Water Resistance Ratings:

• Rating I: Watches are not protected from water. Avoid all moisture.
• Rating III: Do not press watch buttons underwater.
• Rating IV: If exposed to salt water, rinse thoroughly with fresh water and dry.
• Rating V: Watches can be used for scuba diving (excluding depths requiring helium-oxygen mixtures). Some water-resistant watches feature leather straps. Do not wear these watches during swimming or other activities where the strap may become submerged in water.

Watch Care

• Never attempt to open the case or remove the back cover.
• The rubber gasket that protects the watch from water and dust should be replaced every 2-3 years.
• If water enters the watch, have it checked immediately by an authorized CASIO dealer or distributor.
• Do not expose the watch to extreme temperatures.
• While designed for normal use, avoid rough handling and do not drop the watch.
• Do not fasten the strap too tightly. A finger should fit comfortably between your wrist and the strap.
• To clean the watch and strap, use a dry soft cloth, or a soft cloth dampened with water and a mild neutral detergent. Never use volatile substances such as gasoline, solvents, or spray cleaners.
• When not in use, store the watch in a dry place.
• Avoid contact with gasoline, cleaning solvents, spray aerosols, adhesives, paint, etc. Chemical reactions caused by these materials can damage gaskets, the case, and the watch's polish.
• Some watch models have silk-screened designs on their straps. Be cautious when cleaning such 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 sweat or moisture, or storage in high humidity conditions, may lead to damage, tearing, or cracking. To ensure a long service life for the plastic strap, wipe off dirt and water with a soft cloth at the first opportunity.

For Watches with Fluorescent Cases and Straps

Prolonged exposure to direct sunlight may cause the fluorescent color to gradually fade. Prolonged contact with moisture can also cause the fluorescent color to fade. If any moisture gets onto the watch surface, wipe it off as soon as possible. Prolonged contact with any other wet surface may lead to discoloration of the fluorescent color. Ensure the fluorescent surface is free from moisture and avoid contact with other surfaces. Strong friction of a surface with applied fluorescent paint against another surface may cause the fluorescent paint to transfer to that surface.

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

General Operation

Mode Switching

Figure 1 shows the general view of the watch in the Current Time mode. Button A switches between watch modes. The transition between modes occurs in the following sequence:

Current Time Mode → Calendar Mode

Current Time Mode Display:

Displays Hours, Minutes, Seconds, and an AM/PM indicator (if applicable). Example: 10:58:50.

(Diagram description: Shows a watch face with 10:58:50, PM indicator, and labels for Hour, Minute, Second. Below are module numbers like 350/592/692/695/895, 401/501, 1007/1070/1074)

Calendar Mode Display:

Displays Month and Day. Example: 6:30.

(Diagram description: Shows a watch face with 6:30 and labels for Month, Day)

Setting Time and Date

To set the hour:

1. Press Button B twice to select the hour digits for correction.
2. Press Button A to increment the hour value.

To set the minute:

1. Press Button B to select the minute digits for correction.
2. Press Button A to increment the minute value.

To set the month:

1. Press Button B to select the month for correction.
2. Press Button A to increment the month value.

To set the day:

1. Press Button B to select the day digits for correction.
2. Press Button A to increment the day value.

To finish and save settings:

1. Press Button B.

If no buttons are pressed for 2 minutes in correction mode, the watch will automatically return to the Current Time mode.

The calendar system does not account for leap years (29 days in February). Manual adjustment is required for leap years.

Accuracy Adjustment

To adjust accuracy:

1. Press Button B. The second digits will start flashing.
2. Press Button A at the precise moment of a time signal. The second counter will reset to 00.

Accuracy adjustment can be performed approximately once a month using time signals.

Technical Specifications

• Accuracy at Normal Temperature: +-30 seconds per month.
• Current Time Mode: Hours, Minutes, Seconds, AM/PM indicator ("До полудня" / "После полудня" (P)), Month, Day.
• Calendar System: Automatic calendar, 28 days in February.
• Battery Power:
  • Models 350/1007/1074: One battery (CR-2016). Approximate service life: 5 years.
  • Model 401: One battery (BR-1216 or CR-1216). Approximate service life: 5 years.
  • Models 501/592/692/695/1070: One battery (CR-1216). Approximate service life: 5 years.
  • Model 681: One battery (SR-721SW). Approximate service life: 3 years.
  • Model 895: One battery (CR-1216). Approximate service life: 3 years. For this model, the battery cannot be replaced, so its service life is the same as the watch's service life.

Product Information

• Product Name: Wrist electronic / electro-mechanical quartz watches (Men's/Women's).
• Brand: CASIO
• Manufacturer: CASIO COMPUTER Co., Ltd.
• Manufacturer Address: 6-2, Hon-machi 1-chome, Shibuya-ku, Tokyo 151-8543, Japan
• Importer: OOO "Kasio", 127055, Moscow, ul. Suchevskaya, d.27, str. 1, Russia
• Country of Origin: Japan
• Warranty Period: 1 year
• Address for Authorized Claims: As indicated on the warranty card.
• Product Compliance: Complies with GOST 26270-98 (p.4.35). Certificate of Conformity No. RОСС JP. АЯ 46.Д00003.