User guide

OVERVIEW

Functional Buttons

The table below describes what operations are performed for each of the buttons.

Button

Operation Performed

LIGHT (except GDM-461)

Press and hold for 2 seconds to turn the display backlight on or off.

Hold

Press to enter or exit data hold mode.

BLUE Button

Press to select the alternate function.

Yellow (GDM-461)

Hz% (except GDM-461)

Press the Hz% button (except GDM-461) or the Yellow button(GDM-

461) for frequency and duty cycle measurement.

RANGE

 Press RANGE to enter the manual ranging mode; the Meter beeps.

 Press RANGE to step through the ranges available for the selected

function; the Meter beeps.

 Press and hold RANGE for 2 seconds to return to auto range

mode; the Meter beeps

MAX/MIN(except 461)

Press to select the maximum and minimum value.

REL

 Press to enter REL mode.

 Press again to exit REL mode

 For Model GDM-360/397: Press and hold for over 2 seconds to

enter or exit RS232C or USB mode* (optional).

*Note: For the GDM-461, there is no need to hold the REL

key

for 2 seconds as the RS232C/USB mode is enabled by default after

powering on.