the keypad of cpt-711consists of 20 rubber keys and one trigger key. the functions of some special keys are as follows:

    enter enter.

    this key is for command execution or input confirmation.

    bs back space.

    if pressed down longer than one second, a clear code will be sent.

    sp space.

    up cursor up.

    down cursor down.

    alpha the toggle key for alphabet/numeral input.

    when the system is in alpha-mode, a small icon will be shown on the display, and each numeral key can be used to generate one of the three capital letters. for example, numeral 7 can be used to produce a, b or c. pressing the same key twice within one second, will call the letter b. pressing the same key without halting longer than one second, will cause the three letters to be shown in a circulating way. only when stop pressing the key for longer than one second or pressing another key, will the system send the real key code to the application program.

    fn the function key.

    this key can not be activated alone, it must be pressed with one numeral key at the same time. for example, fn + 1 generates function #1, fn + 2 generates function #2, etc (up to 9 functions). also, this key can be combined with the up/down arrow keys to adjust the contrast of the lcd. and when this key is combined with the enter key, it will turn on/off the lcd backlit.

    esc escape.

    usually this key is used to exit current operation.

    power power on/off.

    to prevent a faulty push, it needs about 1.5 sec continuous pressing to turn on/off the power.