the keypad of cpt-720 portable terminal consists of 32 rubber keys and one power switch. the functions of some special keys are as follows:

    bs back space.

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

    shift shift (toggle key)

    when it is in shift mode, an uparrow icon will be shown in the screen. alphabet input will be small letter and f8 can be used to turn on/off the display back-lit. also the f6 and f7 can be used to adjust the display contrast.

    alpha the toggle key for alphabet /numeral input.

    when the system is in alpha-mode, a small icon will be shown on the right most side of the display.

    esc escape.

    usually this key is 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.