Agilent Technologies 8935 Series, Руководство пользователя

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Chapter 3 87
Troubleshooting
Service Screen
3. Rotate the knob and select
SERVICE
.
The SERVICE screen appears. For field descriptions, see “Field Names
and Descriptions” on page 87 .
Field Names and Descriptions
Voltmeter Connection
This field selects the desired circuit node for voltage measurements. To
change the voltmeter connection, use the knob to select the
Voltmeter
Connection
field. A
Choices
menu will appear. Move the cursor to the
desired circuit node in the list and push the cursor control knob. The
reading is displayed in the
Voltage
measurement field at the top- left
of the display.
Because the nodes being measured must be in the range of 0 to ±5 volts,
the measurement of some points are scaled to that measurement range.
For example; the +12 Volt reference (
MEAS_12V_REF)
should measure
about +5volts. The
−
12 Volt reference (
MEAS_NEG_12V_REF)
should
measure about
−
5 volts. Many of the voltage measurements are only
valid after a number of instrument settings are changed.
When run, the diagnostic routines make the necessary circuit changes
and measurements automatically, comparing the measurements to
known limits for each node.
Counter Connection
This field selects the desired circuit node to connect to the Test Set’s
internal frequency counter. The reading is displayed in the
Frequency
measurement field at the top right of the display.
To change the counter connection, use the knob to select the
Counter
Connection
field. A
Choices
menu will appear. Select the desired
circuit node.
Gate Time
This field is used to adjust the Test Set’s internal frequency counter’s
gate time. A shorter gate time may enable you to see frequency
fluctuations that might not be seen using a longer gate time.
To change the gate time, use the knob to select the Gate Time field.
When you select the field a flashing >> cursor is displayed. Rotate the
cursor control knob until the desired gate time (10 to 1000 ms in 10 ms
increments) is displayed, then press the cursor control knob.