Hameg HM8123 User Manual page 21

1 Pressing this button will freeze the display.
2 Setting the trigger level with the numerical keys, the
entered value will be accepted with the unit millivolts
(mV).
ARMED / MHz (pushbutton)
28
Button with two functions:
1 Pressing this button will select the ARMED mode.
2 Setting the gate time with the numerical keys
entered value will be accepted with the unit millise-
conds (ms).
OFFSET / Hz/ns (pushbutton)
29
Pressing this button will activate the OFFSET function.
GATED / kHz/us (pushbutton)
30
Pressing this button will activate the GATED mode.
Function pushbuttons
31
These buttons have two functions:
1 The measurements function are called by operating
these buttons. The corresponding button will light up.
2 Setting the trigger level or the gate time, the desired
value can be entered with this buttons and the unit
buttons (mV , V
27 25
chap. Gate time and Triggering. None of these button
lits.
A B C
G H
Fig. 2.3: Function keys and their meaning
FREQ A Frequency channel A
A
FREQ B Frequency channel B
B
FREQ C Frequency measurement channel C
C
PER A Period channel A
D
34 36
Fig. 2.2: Rear panel of the HM8123
to
A M
and ms , s ). Also refer to
28 28
D E F
I K L M
33
35 38 37
Width A
E
A : B
F
Duty A
G
TI AB
H
TI avg AB Time interval A-B averaged
I
Phase AB Phase difference A-B
K
, the RPM A
31 L
TOTAL A
M
TRIG/ARM INPUT (BNC connector)
32
External gate control input
Rear Panel
Interface
32
USB/RS-232 interface (HO820);
Option: IEEE-488 GPIB (HO880)
A (BNC connector)
34
Trigger signal channel A output (e.g. for display on a
scope). Signal level 0 to +5 V (TTL level)
B (BNC connector)
35
Trigger signal channel B output (e.g. for display on a
scope). Signal level 0 to + 5 V (TTL level)
GATE (BNC connector)
36
Gate view output. This output will be high as long as
the gate is open during a measurement.
10 MHz Ref. (BNC connector)
37
External reference input (10 MHz)
RESET (BNC connector)
38
External reset signal input (TTL level). The function is
identical to that of the RESET pushbutton
Mains input connector
39
Controls and display
Pulse width channel A
Frequency ratio of channels A : B
Duty cycle channel A
Time interval A-B
(only square-wave signals)
Rpm measurement channel A
Event counting channel A
25
39
.
21