Fluke 9100 User Handbook Manual page 114

Final Width = 215mm
4.4.3.5 Phase-Locking Facilities
Access:
Pressing the '∆Φ' key (bottom row) presents a screen with alternative roles
shown against the two top right screen keys:
Phase Lock Role:
(Refer also to the illustration of the rear panel in Section 2, sub-section 2.7.)
Pressing the right-side '∆Φ' screen key permits the unit's output to be phase-
locked to a received external synchronizing signal of the same frequency
(' PHASE LOCK IN ' on the rear panel). The phase of the 9100 output, relative
to the synchronization point, can be altered over a range of ±180°.
After the '∆Φ' key is pressed, the screen reverts to the main AC Voltage
display, but with the addition of a '∆φ' field, used to alter the phase-shift of
the output relative to the received external reference.
The cursors can be transferred to the ∆φ field in Digit Edit to edit the value.
Direct Edit can also be used as described in Section 3.
Reference Output Role:
Pressing the 'REF OUTPUT' screen key produces a synchronizing TTL
signal at ' PHASE LOCK OUT ' on the rear panel, in the same phase as the
' ' input. This can be transmitted as a reference signal for
PHASE LOCK IN
phase-locking the outputs of up to five other 9100 units.
Combined Use
The 9100 can be used in both roles simultaneously: producing a reference
output signal in phase with the '
PHASE LOCK IN
reference, while generating its own synchronized output signals. However, a 'fan-out' system is preferred, with one 'Master' unit
providing the reference for up to five other 'Slaves'.
The Phase-Locking Facility Applies to All Waveforms
Phase-locking is not dependent on the type of waveform, but on underlying timing, and so applies to all output waveforms illustrated
in the figure opposite.
Type of Reference Signal Input
When being phase-locked to an external signal, the synchronization point is the negative-going edge of the synchronizing signal
(negative-going zero-crossing in the case of a sinewave reference signal). To this is added the ∆φ phase-shift value registered on
the screen, determining the phase of the positive-going crossover of the output AC Voltage relative to the synchronization point.
This inversion means that with a request for 0° shift, the output signal appears to lag by 180° on the synchronizing signal phase.
Relative Phase-Shift Magnitude and Direction
The zero phase-shift point is taken as the synchronization point illustrated opposite. On the screen, at values other than zero, the
direction of phase shift ∆φ is indicated by a '+' sign if the output is advanced on the reference input, and a '-' sign if the output is
delayed. ∆φ is resolved in steps of 0.01° as shown on the screen, at any value in the range -180° to +180°.
4.4-6 Section 4: Using the Model 9100: AC Voltage Function
V
.
.
TODAYS DATE
V
V
.
.
TODAYS DATE
V
' input from a master
∆Φ
Peak 1.41421 V
Mean 0.90032 V
REF
OUTPUT
V
kHz
TIME
∆Φ ∆%
WAVE
FORM
Peak 1.41421 V
x
Mean 0.90032 V
÷
V
kHz
Z E R O
∆φ =
°
.
TIME
∆Φ ∆%
WAVE
FORM