Fluke 6135A/PMU, Руководство оператора

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6135A/PMU
Operators Manual
8-8
UUT (cont.)
Problem Probable Cause Action
When a test is run, an
error message appears
“Clock Failure – time not
reliable” (For UUTs that
use GPS antenna input).
For UUTs that are that
have an internal GPS
receiver, there is a
problem with the GPS
signal from the front panel
of the 6135A/PMU System
Timing Unit.
Complete these steps in order:
1. Make sure the GPS Antenna cable to the UUT
is connected to the GPS Antenna Out on the
front panel of the 6135A/PMU System Timing
Unit. See Figure 8-1.
2. Check the UUT for possible indications (LEDs)
that may indicate that the internal GPS is
locked to a the GPS system.
3. On the rear panel of the 6135A/PMU System
Timing Unit, disconnect the “GPS Antenna In”
and connect it directly to the “GPS In” on the
UUT. Wait for the GPS Receiver to lock on to
four satellites.
a. If the UUT successfully locks on to four
satellites, then reconnect the antenna to the
“GPS Antenna In” on the rear panel of the
6135A/PMU System Timing Unit (see
Figure 8-1). Reset the entire system and
wait to see if the GPS Receiver locks on to
satellites in the normal configuration. If 60
minutes passes and the GPS Receiver has
not locked on to four satellites, contact
Fluke Calibration.
b. If the UUT does not lock on to four satellites
with the antenna directly connected, check
the antenna position. See the Microsemi
GPS Receiver and Antenna Installation
Manual for troubleshooting procedures.
When a test is run, an
error message appears
“Clock Failure – time not
reliable” (For UUTs that
use IRIB-B input).
For UUTs that are
connected to an IRIG
input, there is a problem
with the IRIG signal from
the front panel output of
the 6135A/PMU System
Timing Unit.
Complete these steps in order:
1. Make sure the IRIG-B cable to the UUT is
connected to the IRIG-B OUT on the front panel
of the 6135A/PMU System Timing Unit. See
Figure 8-1.
2. Check that the IRIG Present LED on the
6135A/PMU System Timing Unit front panel is
illuminated.
3. Check the UUT for possible indications (LEDs)
that may indicate that the IRIG-B signal is
present.
Measurement Latency
Test reports a large error
or No Valid Data
Available.
The Ethernet Capture
card in the Server PC has
failed to synchronize
correctly to the 1 pps
signal from the GPS
Receiver or has failed to
capture any Ethernet
measurement data from
the UUT.
1. Check that the GPS Receiver reports that it is
Locked.
2. Check the 1 pps cable from the GPS
Receiver to the Ethernet Capture card in the
Server PC.
W
Caution
Use only the correct supplied (blue)
cable because the cable contains an
attenuator and any other cable will
damage the Ethernet Capture card
.
3. Check the Network Tap in the rear of the
System Cabinet. Check that connections are
as shown in Figure 8-1. The Network Tap
may need to be power cycled by temporary
removing the power supply plug from the rear
of the Network Tap.