FS9922-DMM4

Rev. 1.4

13/37

10. Keys Definition

RANGE Key

Range key is the Auto/Manual measurement key that acts with trigger. Auto measurement is pre-set as

power-on, and switches to Manual measurement when the key is pressed one time. In Manual measurement

mode, mode will move upward upon each press to the highest mode, then return to the lowest mode as a loop.

If press the key over 2 seconds, the system will switch back to Auto measurement status.

RELΔ/RS232 Key

A. RELΔ Measurement

acts with trigger. Press this key will enter into the relative value measurement mode. The

system will save the display value in the memory as the reference value. When doing the

measurement later, the display value will be the difference value that the entry value deducts the

reference value.

3) The relative value measurement can be carried out under the certain measurement mode, i.e., the

function is available only under the Manual Measurement Mode.

6) Press the key in HOLD status, HOLD function will be cancelled. The system will save the display

value in the memory as the reference value. When doing the measurement later, the display

value is the difference that the entry value deducts the reference value.

7) Press RANGE, SELECT Key or use Mode Switch will cancel RELΔ measurement mode, and go

back to the normal mode (RELΔwill disappear in the LCD).

the measurement mode. Press the key again, the relative measurement function will be

B. RS232 Communication Transmission

status (“RS232” shows in LCD).

cancelled.

3) The auto power off function is cancelled in RS232 status, and the signal of “APO” in LCD

disappears.

HOLD/LIGHT Key

HOLD/LIGHT is the reading hold/backlight control key.

A. Reading HOLD

1) Press the key, the display value will be locked and kept unchanged, “HOLD” shows in LCD. Press

the key again, the locked status will be unlocked, and enter into the normal measurement status.

2) HOLD function will be unlocked and go back to the normal status when RANGE, SELECT, REL

Key or Mode Switch is pressed or used.

B. BACK LIGHT CONTROL

1) The backlight control signal will be started when the HOLD key is pressed longer than 2 seconds;

then, press the key again longer than 2 seconds, the backlight control signal will be shut off. If

the HOLD Key is not pressed longer than 2 seconds after the backlight source is started, the light

source will be shut off automatically in 10 seconds.