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Model 8902A
Operation
NOTE
Pre-Display
is no1
tiirned
of
if
the Audio RMS Detector
(OS)
is
on
when P O is
selected. In (his case, FM Dtwmphasis will be tiirned
ofl
birt Pre-display
w i l l
be Icfl
on. Prtvhplay is rcqiiircd by
thc A iidio RMS hardware.
0
T2 and
T3
(Trigger Immediate and Trigger With Settling). Trigger codes should always appear
at the end of a program string, and the triggered measurement results must be read before
any additional program codes are sent to ensure an accurate measurement. When either
o f
the trigger codes T2 o r T3 is received by the Measuring Receiver, a measurement cycle is
immediately initiated.
Programming Examples
Code String Example
Function codes may be sent to the instrument in a continuous string as
shown below. The code string shown will program the instrument to determine the positive peak
de-emphasized (75
ps)
FM deviation of an input signal at 104.5 MHz. The measurement is triggered
with T3, Trigger with Settling.
OUTPUT714;" AU 104.5 MZ M2 D1 P1 P4
I
Automatic Operation
Frequency (Manual Tuning)
Units
FM
Peak+ Detector
1
FM De-emphasis and Pre-display
75 ps FM De-emphasis
Trigger w/Settling
Example Measurement Program
The following example provides you with a sample of how the
previous information might be used to program the HP 8902A to make a particular measurement.
This example demonstrates measuring AM in the 50 Hz to 15 KHz bandwidth of a 100 MHz carrier
using Trigger Hold and Trigger with Settling.
10 OUTPUT 714; "IP"
20 OUTPUT 714; "M1 100 MZ H1 L2 T1"
Instrument Preset to configure instrument
to a known state.
Send code to configure instrument for measurement.
30
OUTPUT 714; "T3"
40 ENTER 714;A
50 PRINT A
60 END
Trigger settled measurement.
Read data into variable A.
Print variable A
Reference Tables
Table 3-1 1, "Measuring Receiver Function to Code Summary"
This table lists the instrument-
specific fLinction code for each Measuring Receiver function described in the Detailed Operating
Inslriictions of this manual.
Table 3-12, "Code to Measuring Receiver Function Summary"
This table has the same information
as Table 3- I I, "Measuring Receiver Function to Code" but is organized alpha-numerically by code.
3-17
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