Casio 4312/4313 What is a radio-controlledwatch, Calibration Signal, Reception Ranges, Location, Receiving the Calibration Signal, ■To position the watch for optimum reception

Operation Guide 4312/4313

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 is received by

Transmitter Long-wave time built-in antenna. calibration signal

Watch decodes received data and

Signal data converts it to time data.

	Decode
Cesium	Time data	Time is adjusted
Cesium		according to time
atomic clock Watch	Internally	according to time
atomic clock Watch	Internally	data.
		data.

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.

Calibration Signal

•The Japanese calibration signal (Call Sign: JJY) is maintained by the National Institute of Information and Communications Technology (NICT). It is transmitted 24 hours a day from the Mt. Otakadoya transmitter (40 kHz) located in Tamura-gun, Fukushima Prefecture, and from the Mt. Hagane transmitter (60 kHz) 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.

The time data of the Japanese calibration signal (Call Sign: JJY) is maintained by the Japan Standard Time Group of the National Institute of Information and Communications Technology (NICT). Note that transmission of the standard wave may be interrupted occasionally due to maintenance, lightning, etc.

For more information, visit the website of the Japan Standard Time Group of the National Institute of Information and Communications Technology (NICT) at the following URL.

http://jjy.nict.go.jp

•Note that the above URL is subject to change.

Reception Ranges

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.

•For information about selecting a Home City, see “Configuring Home Time Settings”. See “World Time City Code List” for details on city codes.

	Home City	Transmitter

		Either the Mt. Otakadoya signal
		(40 kHz) or the Mt. Hagane signal
	TYO, SEL, HKG	(60 kHz)
	TYO, SEL, HKG	• Use one of these settings for
		• Use one of these settings for
		reception of the Japanese signal in
		Japan or Taiwan.

	YVR, LAX, YEA, DEN,	Fort Collins, Colorado signal
	YVR, LAX, YEA, DEN,	• Use one of these settings for
	MEX, YWG, CHI, MIA,	• Use one of these settings for
	MEX, YWG, CHI, MIA,	reception of the U.S. signal in
	YTO, NYC, YHZ, YYT	reception of the U.S. signal in
	YTO, NYC, YHZ, YYT	North America.
		North America.

•CASIO does not guarantee that the watch will be able to receive a calibration signal correctly each day.

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

•Best reception is possible late at night.

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.

Among or near buildings

Near high-voltage lines

Inside a vehicle	Next to a household appliance or
(automobile, train, plane, etc.)	office equipment (TV, speaker, fax,
	PC, mobile phone, etc.)

In a location where there is	Near mountains
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.

Receiving the Calibration Signal

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

•Auto receive (Reception is performed automatically at midnight, 1:00, 2:00, 3:00, and 4:00 each morning.)

•Manual receive (You initiate reception using a button operation.)

•If reception is not successful for any of the normal auto receive operations shown above, auto receive is performed one more time at 5:00 a.m.

•The watch is set up for auto receive at the factory, so all you need to do is to place it in a location that allows good reception each night.

■To position the watch for optimum reception

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

Time Required for Reception

Signal reception takes anywhere from about two to seven minutes. In cases where receipt is not possible from the transmitter from which the signal was last received, reception may take up to 14 minutes.

■To perform signal reception manually

In the Timekeeping Mode, hold down the Dbutton for about two seconds.

• The watch will beep and reception will start. The receive indicator cycles from “Unstable” through “Stable” as shown below while reception is in progress. How far it cycles depends on the signal strength.

■To interrupt reception

Press the D button.

•All other buttons besides Dare disabled during signal reception.

When reception is successful

The watch terminates reception and adjusts the current time. Next it beeps and then displays the date and time the adjustment was performed.

The receive indicator on the display also indicates successful signal reception. The indicator is cleared from the display each day at midnight.

When reception fails (ERR Indicator)

In the case of an error, the watch will not adjust its current time setting, but display “ERR” instead.

•The display will return to the normal timekeeping screen automatically if you do not perform any operation for about one or two minutes.

Receive Indicator

The receive indicator cycles from	Indicator
“Unstable” through “Stable” as
shown below while reception is in
progress. How far it cycles depends
on the signal strength.
Keep the watch in a location where
reception is stable while reception is
in progress.

Module 4313

Indicator

Module 4312

UnstableStable

Module 4313

•Even under optimum reception conditions, it can take about 10 seconds for reception to stabilize.

•Use the 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.

■To view the last reception date and time

In the Timekeeping Mode, press the Dbutton.

•This displays the date and time when signal reception was last successful, and the current time and date were last adjusted.

•The “” indicator and the last reception date screen alternate at two-second intervals.

•To return to the Timekeeping Mode, press the D button again.

•The display will return to the normal timekeeping screen automatically if you do not perform any operation for about one or two minutes.

Reception Date

Reception Time