Rear Inputs/Outputs; Measuring Functions - Fluke PM6690 Service Manual

Selected Function Action
FREQ A
FREQ B
FREQ C
FREQ RATIO A/B
FREQ RATIO C/B
PER SINGLE A
PER SINGLE B
PER AVERAGE A
PER AVERAGE B
PULSE POS A
PULSE NEG A
TIME INT A to B
Select NEG
SLOPE B
Select AUTO
RISE TIME A
trigger
FALL TIME A
PHASE A rel B
PHASE B rel A
PHASE A rel A
DUTY POS A
DUTY NEG A
VOLT MAX A
VOLT MIN A
Table 2-8
Measuring functions check
1) Value depends on the symmetry of the signal.
2) Exact value depends on input signal.
3) If an RF option is installed.
level = 0.5V
Trig
coupling
DC
The standard deviation (
Std
2-6 Performance Check, Rear Inputs/Outputs
Display
10 MHz 2)
10 MHz 2)
- - - - - - - - - - - - - - 3)
1.0000000
0.0000000 3)
100 ns 2)
100 ns 2)
100 ns 2)
100 ns 2)
50.000 ns 1)
50.000 ns 1)
0 ± 1 ns
50.000 ns 1)
30.000 ns 2)
30.000 ns 2)
180° or -180° 1)
180° or -180° 1)
0°
0.500000 1)
0.500000 1)
+0.75 V 2)
-0.75 V 2)
) should be <100 ps.
P/F

Rear Inputs/Outputs

10 MHz OUT
– Connect an oscilloscope to the 10 MHz output on the
rear of the counter. Use a coaxial cable and 50 W termi-
nation.
– The output voltage should be sinusoidal and above 1
V (2.8 V
RMS
EXT REF FREQ INPUT
– Recall the DEFAULT settings.
– Connect a stable 10 MHz signal (e.g REF OUT from an-
other counter) to input A.
– Connect a 10 MHz, 100 mV
the LF synthesizer to EXT REF IN.
– Select Ext Ref. by keying in the following sequence:
SETTINGS
– The display should show 10 MHz.
– Change the external reference frequency to 5 and
1 MHz.
– The counting should continue, and the display should
still show 10 MHz.
EXT ARM INPUT
– Proceed from the test above.
– Select
MAN
– Settings for the pulse generator:
single shot pulse, manual trigger,
amplitude TTL = 0 - 2 V
duration = 10 ns.
– Connect the pulse generator to Ext Arm Input.
– Activate start arming by keying in the following se-
quence:
SETTINGS
– The counter does not measure.
– Apply one single pulse to Ext Arm Input.
– The counter measures once and shows 10 MHz on the
display.

Measuring Functions

– Connect a 10 MHz sine wave signal with approx.
amplitude into 50 W via a power splitter to Input
1 V
RMS
A and Input B, e.g. from 10 MHz Out on the rear panel.
– Recall the DEFAULT settings.
Select the following settings for the timer/counter via
A and INPUT B
W impedance for A and B.
–
50
– ual trigger.
MAN
).
p-p
, (0.28 V
RMS
® ®
Timebase Ref Ext
ual trigger.
, and
PP
® ®
Start Chan E
:
) signal from
P-P
INPUT