Casio 2671 User Manual

MA0302-A

USER’S GUIDE 2581/2671

The following explanation covers the radio-controlled timekeeping function only. For other functions, go to the download page for Module 2578, which is the export model that has the same functions, except for radio-controlled timekeeping.

How a Radio-controlled Watch Works

What is a radio-controlled watch?

Your radio-controlled watch is designed to receive a time calibration signal that contains standard time data and adjust its current time setting accordingly.

Signal received using

Decoding

built-in antenna.

Watch decodes received data and converts it to time data.

Time is adjusted according to time data.

Transmitter

Cesium atomic clock

After the watch receives the Standard Time signal, it performs internal calculations to determine the current time. Because of this, there may be an error of up to one second in the displayed time.

Long-wave time calibration signal

Inside the watch

Watch

Signal data

Time data

Location

Reception is difficult and may even be impossible in the locations described below. Avoid such locations when performing signal reception.

 You should think of your watch operating like a radio or TV when it

is receiving the calibration signal.

Near high-voltage linesAmong or near buildings

Inside a vehicle (automobile, train, plane, etc.)

In a location where there is radio interference (construction site, airport, etc.)

If you are experiencing problems with reception, move away from the types of locations described above to a location with better reception, and try again.

Next to a household appliance or office equipment (TV, speaker, fax, PC, etc.)

Near mountains

Calibration Signal

 The Japanese calibration signal (Call Sign: JJY) is maintained by

the independent Japan Ministry of Posts and Telecommunications Communication Research Laboratory (CRL). It is a long wave signal transmitted 24 hours a day from the Mt. Otakadoya transmitter (40kHz) located in Tamura-gun, Fukushima Prefecture, and from the Mt. Hagane transmitter (60kHz) located on the border between Saga Prefecture and Fukuoka Prefecture.

 The U.S. calibration signal (Call Sign: WWVB) is transmitted by

the National Institute of Standards and technology from Fort Collins, Colorado.

Though the calibration signal is normally transmitted 24 hours a day, transmission may be interrupted occasionally due to maintenance, lightening, etc.

Receiving the Calibration Signal

There are two methods you can use to receive the time calibration signal.

 Auto reception (Reception is performed automatically at 2:00,

4:00, and 6:00 each morning.)

 Manual reception (You initiate reception using a button

operation.)

 The watch is set up for auto reception at the factory, so all you

need to do is to place it in a location that allows good reception each night.

Setting Up to Make Reception Easier

Remove the watch from your wrist and place it somewhere so its top (12 o’clock side, where the antenna is located) is facing approximately in the direction of the signal transmitter. Keep the watch away from metal objects.

Resin band

Metal band

 Orienting the watch so it is sideways to the transmitter makes it

more difficult to receive the signal.

 Do not move the watch while it is receiving the calibration signal.

Reception Range

This watch is designed to receive the standard time calibration signal of Japan (JJY) or of the United States (WWVB). The signal that is received depends on the current Home City setting.

When this Home City is selected: You can receive this signal

Either the Mt. Otakadoya signal (40kHz) or the Mt. Hagane signal (60kHz)

Fort Collins, Colorado signal

1000km

500km

1000km

Mt. Otakadoya (40kHz)

Transmitter Location

1000km

Fort Collins

 Under optimum conditions, the calibration signal should be

receivable up to 3,000 kilometers from the transmitter. Note that the wave is relatively weak at distances greater than 1,000km, so reception may be poor at long distances.

Receive Icon and Indicator

While reception is in progress, the

icon and the receive indicator cycle from “Unstable” through “Stable” as shown below. How far they cycle depends on the signal strength. Keep the watch in a location where reception is stable while reception is in progress.

Unstable Stable

 Even under optimum reception conditions, it takes at least

10 seconds before reception starts.

 Use the receive icon and receive indicator to check

reception status and to determine the best location for signal reception.

 Note that weather, the time of day, surroundings, and other

factors can all affect reception.

Transmitter Locations

Mt. Hagane (60kHz)

 Under optimum conditions, the calibration signal should be

receivable up to 1,000 kilometers from the transmitter. Note that the wave is relatively weak at distances greater than 500km, so reception may be poor at long distances.

 Geographic contours, nearby buildings, the season, and the time of day can make reception impossible even when you are within range of

the transmitter.

 Best reception is possible late at night.

500km

Time Required for Reception

Signal reception takes anywhere from about two to six minutes.  Note that when “A/T” (auto) is specified as the transmitter

selection mode, signal reception can take up to 12 minutes.

* See “Specifying the Transmitter Selection Mode in Japan” for

more information.

Triggering Reception Manually

In the Timekeeping Mode:

Hold down the about two seconds.

 The watch beeps and reception

starts. Ongoing reception is indicated by the icon and the receive indicator. See “Receive Icon and Indicator” for more information.



To interrupt reception

Press the

All other buttons besides B are disabled during signal reception.



When reception is successful

The watch adjusts its current time setting, and then beeps and displays the time and date of the adjustment.

 The icon and the receive indicator remain on the display to

indicate that reception was successful.



When reception fails

The watch does not adjust its current time setting, and displays “ERR” instead.

 The display also return to the normal timekeeping screen

automatically if you do not perform any operation for about one or two minutes.

B button for

B button.

3000km

Receive indicator

Receive icon

USER’S GUIDE 2581/2671

Viewing the Last Reception Date and Time

In the Timekeeping Mode:

Press the

B button.

 This displays the date and time that signal reception was

complete and the current time and date were adjusted.

 The month and day screen and hour and minute screen alternate

at two-second intervals.

 To return to the timekeeping screen, press the B button again.  The display also returns to the normal timekeeping screen

automatically if you do not perform any operation for about one or two minutes.

Important!

 The calibration signals received by this watch include two data

groups: an hour-minute-second group and a year-month-day group.

 The icon will remain on the display only if the hour-minute-

second group and year-month-day group are both received. It will not remain on the display if only the hour-minute-second group is received.

Hour-minute-second group and yearmonth-day group received

Hour-minute-second group only received

 If only the hour-minute-second group is received, the Timekeeping

Mode date at the time of reception is recorded as the last reception date.

Home Time

(24-hour format)

2-second interval

Reception date and time

displayed

not displayed

3. Select the transmitter selection mode you want.

C and

A cycle

(Back)

(Forward)

Use through the settings until the one you want is displayed.

* A/T

With this setting, the watch automatically selects either the Mt. Otakadoya signal (40kHz) or the Mt. Hagane signal (60kHz), whichever is strongest. *

The frequency first used by the watch is the one that was last successful.

* JPN 40

With this setting, the watch always receives the Mt. Otakadoya signal (40kHz).

* JPN 60

With this setting, the watch always receives the Mt. Hagane signal (60kHz).

4. Exit the setting screen.

Press the

B button 10 times.

 This exits the setting screen can causes “ ” to appear

on the display. To return to the timekeeping screen, press the C button once (or the A button six times).

 The display also will return to the normal timekeeping screen

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

Turning Auto Reception On and Off

1. Display the setting screen.

In the Timekeeping Mode:

Use the

A button to

display the “ ” indicator, and then press

the

B button.

 This causes the current setting

(On or OF) to appear on the display.

2. Turn auto reception on or off.

C or

A to toggle

Press the auto reception setting on (On) and off (OF).

Calibration Signal Reception Precautions

 Auto reception can be performed while the watch is in the

Timekeeping Mode or World Time Mode only.

 Operating any button while auto reception is in progress will cause

the watch to beep and then exit the receive operation.

 Make sure you are within the range of the calibration signal

transmitter before performing the receive operation. Remember that geographic contours, nearby buildings, the season, and the time of day can make reception impossible even when you are within range of the transmitter.

 Proper reception may be impossible if there is something blocking

the signal. If reception is unsuccessful, try again.

 This watch is designed to adjust its current time setting in

accordance with the calibration signals transmitted in Japan and the United States only. Note that you will need to make your own adjustments when using this watch outside of Japan or the United States, or in any area that is outside the range of one of the receivable time calibration signal transmitters.

 When the watch is unable to adjust its time signal using the

calibration signal for some reason, timekeeping accuracy is within

±15 seconds per month.  Strong electrostatic charge can cause timekeeping error.  Signal reception is cancelled if an alarm starts to sound while it is

being performed.  The watch’s calendar shows dates up to the year 2039. Attempting

a receive operation after that causes an error.

3. Exit the setting screen.

Press the

B button 11 times.

 This exits the setting screen can causes “ ” to appear

on the display. To return to the timekeeping screen, press the C button once (or the A button six times).

 The display also will return to the normal timekeeping screen

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

Specifying the Transmitter Selection Mode in Japan

When Tokyo (TYO) is selected as the Home City, you can select either of two different transmitters for reception.

 The initial factory default settings of the watch are TYO (Tokyo) for

the Home City, and A/T (auto) for the transmitter selection mode.

1. Display the setting screen.

In the Timekeeping Mode:

Use the

A button to

display the “ ” indicator, and then press

the

B button.

 This causes the current auto

reception setting (On or OF) to appear on the display.

2. Display the transmitter selection mode setting screen.

Press the

B button.

Troubleshooting

Cannot perform manual reception.

Possible Cause:  The watch is not in the Timekeeping

Corrective Measures:  Perform manual reception while a time

The icon is not displayed even though auto reception is turned on.

Possible Cause:  A single receive operation was not

Corrective Measures:  Check to make sure the watch is in a

Mode or World Time Mode.

 The Home City is set to a city other than

TYO (Tokyo), NYC (New York), CHI (Chicago), DEN (Denver), or LAX (Los Angeles).

screen is on the display in the Timekeeping Mode or World Time Mode only.

 Change Home City To TYO (Tokyo), NYC

(New York), CHI (Chicago), DEN (Denver), or LAX (Los Angeles).

successful.

 Both the hour-minute-second group and

year-month-day group were not received.

 The watch is not in the Timekeeping

Mode or World Time Mode when an auto reception time is reached.

 You performed manual reception, which

clears the icon from the display.

location where it can receive the signal.

 Place the watch in a location where

reception conditions are good.

 Make sure that the watch is in the

Timekeeping Mode or World Time Mode during the auto reception times.

 The icon disappears from the display

whenever you change the current time setting manually.

Time setting is incorrect following signal reception.

Possible Cause:  Summer time is turned on or the wrong

Corrective Measures:  Turn off summer time so the DST

 If you cannot receive the calibration signal or if the current time

setting is incorrect after signal reception, check the current setup of the watch. The following are the watch’s factory default settings, which are configured automatically whenever you have the battery of the watch replaced.

Auto Receipt

Transmitter

Home City

Summer Time

Home City is selected.

indicator is not on the display.

 Configure the watch for the correct DST

setting and Home City setting.

Auto Japan transmitter select (40kHz/ 60kHz)

Tok y o

Auto (according to signal data)