Tektronix CMC251, User Manual

Page: 14 / 38

Getting Started
4
CMC251 User Manual
2. OVERRANGE Indicator. Lights when frequencies above the
specified limits are applied to either channel.
3. Display. The display area provides measurement information on
the digital display. Single LEDs indicate the units and conditions
of the display.
4. kHz s Indicato r Lights when a frequency mode is selected and
the PRESCALE button is in its out position, indicating that the
reading is in kilohertz. When the period or pulse mode is
selected, the LED lights to indicate the reading is in
microseconds.
5. MHz Indicator. Lights when a frequency mode is selected and the
PRESCALE button is pressed in, indicating that the reading is in
megahertz.
6. GATE Indicator. Lights while the frequency counter is making a
measurement. The LED extinguishes when updating the display.
7. Gate Resolution Indicators. These LEDs light to indicate the
present gate resolution settings (X1, X10, X100, or X1000).
8. POWER Switch. Powers the instrument on and off.
9. GATE Button. Determines the display’s degree of resolution by
setting the gate time (the amount of time the counter uses to
derive its displayed value). The selected resolution is indicated by
the lighted LED. Each press of the button changes the degree of
resolution to the next level.
10. FUNC Button. Determines the operating mode of the CMC251
Frequency Counter.
11. HOLD Button. Stops or locks the display when pressed in.
Toggling the button to its out position allows the measurement to
continue. When using the TOTAL mode, pressing the HOLD
button freezes the display but event counting continues.
12. RESET Button. Sets the display to all zeros; new measurements
will be displayed after the button is released.