HP 11757B User manual

Printed in USA March 2000
Notice
Hewlett-Packard to Agilent Technologies Transition
This documentation supports a product that previously shipped under the Hewlett-
Packard company brand name. The brand name has now been changed to Agilent
Technologies. The two products are functionally identical, only our name has changed. The
document still includes references to Hewlett-Packard products, some of which have been
transitioned to Agilent Technologies.

Making Measurements
with the HP 11757B
Multipath Fading Simulator
SERIAL NUMBERS
Attached to the rear panel of the instrumentis a
serial number plate. The serial number is in the form:
0000A00000. The rst four digits and the letter are
the serial number prex. The last ve digits are the
sux. The prex is the same for identical instruments; it
changes only when a conguration change is made to the
instrument. The sux, however, is assigned sequentially
and is dierent for each instrument.
This manual applies to instruments with serial numbers
prexed 3108A and ab ove.
ABCDE
HP Part No. 11757-90050
c
 HEWLETT-PACKARD COMPANY 1992
5301 Stevens Creek Blvd., Santa Clara, California 95052
Printed in USA

2Chapter1
Contacting Agilent
By internet, phone, or fax, get assistance with all your test and measurement needs.
Table 1-1 Contacting Agilent
Online assistance: www.agilent.com/find/assist
United States
(tel) 1 800 452 4844 Latin America (tel) [phone]
(fax) [phone]
Canada
(tel) 1 877 894 4414
(fax) [phone]
Europe
(tel) ([phone]
(fax) ([phone]
New Zealand
(tel) 0 800 738 378
(fax) ([phone]
Japan
(tel) ([phone]
(fax) ([phone]
Australia
(tel) 1 800 629 485
(fax) ([phone]
Asia Call Center Numbers
Country Phone Number Fax Number
Singapore 1-800-375-8100 (65) 836-0252
Malaysia 1-800-828-848 1-800-801664
Philippines (632) 8426802
1-800-16510170 (PLDT
Subscriber Only)
(632) 8426809
1-800-16510288 (PLDT
Subscriber Only)
Thailand [phone] (outside Bangkok)
[phone] (within Bangkok) (66) 1-661-3714
Hong Kong 800-930-871 (852) 2506 9233
Taiwan 0800-047-866 (886) 2 25456723
People’s Republic
of China 800-810-0189 (preferred) 10800-650-0021 10800-650-0121
India 1-600-11-2929 000-800-650-1101

1
Digital Radio Testing
This guide contains detailed instructions for performing
digital radio tests with the HP 11757B Multipath Fading
Simulator. The tests detailed in this chapter include:
Static M-Curve Measurement
Dynamic M-Curve Measurement
Dynamic S-Curve Measurement
Hysteresis M-Curve Measurement
Recovery Time Test
Bit Error Rate Test
Note
If you have an option 001 HP 11757B Multipath Fading
Simulator, this guide do es not apply to your instrument.
Use the Operating and Programming Reference.
BERT
The tests detailed in this guide use a Bit Error Rate
Test Sets (BERT) to supply and receive data, and count
errors. There are other alternatives. Some digital radio
systems have their own internal error checking scheme
with an error pulse output. This will allow elimination
of the BERT. Another possibilit y is simply using the
Alarm Output of the radio, and simplifying tests to
lo ck/out-of-lock transition measurements.
1-1

Digital Radio Testing HP 11757B
Connecting the HP
11757B to a BERT
The HP 11757B can work with many dierenttypes
of Bit Error Rate Test Sets (BERT). However, not all
BERT operate the same way and it is imp ortant for you
to understand how to correctly interface dierenttypes
of BERTs to the HP 11757B.
Triggering
The 4
RADIO SETUP
5 key can b e used to adjust the
triggering of the ERROR PULSE INPUT and ALARM
INPUT connectors to coincide with the BERTyou
are using. The ERROR PULSE INPUT line can be
terminated in ECL/75, TTL/75, or TTL/ 10k. In
addition, an ERROR PULSE INPUT variable threshold
can b e selected instead of ECL or TTL thresholds.
ERROR PULSE INPUT variable threshold is only
available in serial prexes 3235A and above. The HP
11757B will always trigger on the rising edge of signals
applied to the ERROR PULSE INPUT connector.
The ALARM INPUT connector is always terminated
in TTL/10k. However, the edge (p ositiv e or negative
going) that the Fader triggers on can b e chosen byyou.
Select the one that works with your BERT.
Error Pulse Signals during Out-of-Lock Situations
It is very imp ortant to understand what kind of
\ERROR PULSE" signal your BERT puts out when
the radio is out-of-lo ck. Ideally, when the radio is
out-of-lo ck, the BERT will put out a very fast stream
of pulses indicating a very high Bit Error Rate (BER).
If this is the case with your BERT, all you need do for
BER Criteria measurements is connect the \ERROR
PULSE" of your BERT to the ERROR PULSE INPUT
connector on the front panel of the Fader.
On the other hand, some BERTs turn o their \ERROR
PULSE" signal when an out-of-lo ck state is detected.
If this is the case with your BERT, you not only need
1-2

HP 11757B Digital Radio Testing
to connect the \ERROR PULSE" of the BERT to the
ERROR PULSE INPUT of the Fader, you must also
connect an Alarm line from either your radio or your
BERT to the ALARM INPUT line of the Fader. This
is because when no errors are present on the ERROR
PULSE INPUT line, the Fader cannot tell the dierence
between an out-of-lo ck situation and one were the bit
error rate is truly zero. The Fader needs the ALARM
INPUT line to determine which of these situations is
o ccurring.
1-3

Digital Radio Testing HP 11757B
Static M-Curve
Measurement
Equipment Setup
1. The basic setup for all measurements involves
interrupting the IF path of the digital radio with a
fading simulator. If a Bit Error Rate Tester (BERT)
is used, connect the appropriate data channels. In
the gure b elow, the DS3 data out from the BERT
is connected to the DS3 input of the transmitter,
and the BASEBAND output of the receiv
er to the
DS3 data input of the BERT. DS3 is used only as an
example; if your radio requires another data format,
use a BERT that pro duces it. The ERROR OUTPUT
of the BERT is connected to the ERROR PULSE
INPUT of the Fader. This input can b e set to matc
h
the imp edance of the BERT.
Note
Some digital radios have their own error outputs and
internal data checking schemes that limit the need for
a BERT. See the manual for your radio if you wish
to connect the ERROR PULSE INPUT of the Fader
directly to the radio. There may be a connection that
must be made b etween two p orts of the radio system for
this to work.
2. The RF output of the transmitter is connected to the
RF input of the receiver. Appropriate attenuation is
used to protect the RF input of the receiver. Check
the manual of the receiver and the transmitter to
insure safe levels for the receiver input.
3. The Alarm Output on the receiver can b e connected
to the Alarm Input on the Fader. This connection is
only needed for recovery tests, and tests where no
BERTisavailable and you want to use the ALARM
INPUT to indicate failure.
1-4

HP 11757B Digital Radio Testing
Figure 1-1. Static M-Curve Measurement Test Setup
4. Connect the Fader, BERT and Digital Radio as
shown in gure 1-1.
5. Press 4
MEAS TYPE
5 . Use the 4
85
key until the display
shows STATIC , then press 4
ENTER
5 .
Radio Setup
1. Press 4
RADIO SETUP
5 .
2. The rst item displayed reads 0 BIT RATE . Press
4
ENTER
5 to see what the bit rate is set to. The
preset value is 44.7 MHz (DS3). If you want to set
another bit rate use the arrow or data keys and press
4
ENTER
5 .
3. The display then reads 1 ERROR TERM . Press
4
ENTER
5 to nd the present setting. Use the 4
85
key
to toggle to the termination appropriate for y
our
BERT, then press 4
ENTER
5 .
4. The display then reads 1.1 ERROR THR . Press
4
ENTER
5 to see what the variable error threshold is
set to. If you want to set a dierent threshold use
the arrow or data keys. Cho ose a threshold setting
(combined with the ERROR TERM setting) that
is appropriate for your BERT, then press 4
ENTER
5 .
1-5

Digital Radio Testing HP 11757B
Error pulse input variable threshold is only available
in serial prexes 3235A and above.
5. The display next reads 2 ALARM POL .You will not
need to set this unless you are planning to use the
ALARM INPUT for this test. Press the 4
85
key to
advance to the next feature.
6. The display should read 3 SCALE FACT . The
PRESET scale factor is 1.0, and this should only be
changed if your BERT's error output is sending out
error pulses at a rate other than it is detecting them.
For instance, if the error output of your BERTis
sending one pulse for every four errors, set the scale
factor to four. To set the SCALE FACTOR press
4
ENTER
5 when 3 SCALE FACT is displayed, then use
the 4
85
arrowkey to display the factor your want,
then press 4
ENTER
5 again.
7. The display should now read 4AGC ON/OFF .AGC
(Automatic Gain Control) maintains the p ower level
of the sp ectrum sent through the Fader. You may
want the power level to remain constanteven though
a notchissweeping through the band. If you are
interrupting the digital radio after its own internal
ALC or AGC circuitry,you mayhave to use the
Fader's internal AGC circuitry to prevent non-fade
eects from distorting measurement results. Press
4
ENTER
5 , then use the 4
85
key to displayAGC ON if
AGC OFF is displayed. Press 4
ENTER
5 to exit.
8. The display should now read 5AGC FREQ . If the
AGC is ON, you should ensure that you have the
proper AGC center frequency set. Press 4
ENTER
5
and the display will change \ AGC FRQ 070.0 "or
whatever frequency mayhave b een set previously.
Use the arrow or data keys to set the desired
frequency, then press 4
ENTER
5 .
9. The display should now read \ 6AGC BW ". This
allows you to set the bandwidth to distribute the
1-6

HP 11757B Digital Radio Testing
AGC p ower over. Press 4
ENTER
5 to see what value
this is set to. Use the arrow or data entry keys to
set a value. Use a value close to the radio's channel
bandwidth, then press 4
ENTER
5 .
10. The display should now read \ 7WAIT TIME ". This
allows you to set the wait time after every notch
movement. This wait allows your radio some settling
time b efore a Bit Error Rate measurement is made
by the Fader. Press 4
ENTER
5 to see what value this is
set to. Use the arrow or data entry keys to set a new
value if desired, then press 4
ENTER
5 .
11. The display should now read \ 8 MAX SLEW ". This
allows you to set the notch's maximum slew rate
during measurements. Press 4
ENTER
5 to see what
value this is set to. Use the arrow or data entry keys
to set a new value if desired, then press 4
ENTER
5 .
12. The display should now read \ 9 SYMBL TIME ".
This allows you to set the symbol time of your radio.
You will not need to set this unless y
ou are planning
to p erform a CCIR DFM calculation. The radio
setup is now complete. CCIR DFM is only available
in serial prexes 3215A and ab ove.
Measurement Setup
1. Press 4
MEAS SETUP
5 . This will access a series of
parameters to enter to set the Fader up for a
measurement.
2. The rst item displayed under 4
MEAS SETUP
5 is \ 0
DATA PTS ". This sp ecies the numb er of linearly
spaced frequencies to calculate and measure in the
band you have selected. Press 4
ENTER
5 to access, then
use the arrow or data keys to enter a value, then
press 4
ENTER
5 to get the next parameter. 11 is a go o d
value to enter to keep the measurement time down.
3. The second and third items will b e \ 1 STRTFRQ "
and \ 2 STOP FRQ ". These access the start and stop
1-7

Digital Radio Testing HP 11757B
frequencies for the notch. Press 4
ENTER
5 to access
STRT FR, then use the arrow or data keys to set a
value in MHz (use 45 for this example), then press
4
ENTER
5 . The display should show 2 STOP FRQ .
Press 4
ENTER
5 and set a value using data or arrow
keys (95 for this example), then press 4
ENTER
5 .
4. The next two items displayed are \ 3STARTRATE "
and \ 4 STOP RATE ". These parameters are used
for S-Curve measurements and will b e ignored when
making M-Curve measurements. Press 4
95
until the
display reads \ 5 ERROR BITS ".
5. ERROR BITS determines the numb er of errors that
are counted b efore a nal bit error rate calculation is
made. You mayenter powers of 2 from 2 to 15 (4 ,
8, . . . , 32768). Press 4
ENTER
5 to access and use the
4
85
arrow key to get 2
11
, which equals 2048. Press
4
ENTER
5 .
6. The next displayed item is \ 6 PHASE ". Press
4
ENTER
5 and use the 4
85
arrow key to toggle b etween
the three options: MIN, NON-MIN and BOTH .
When b oth is displayed, press 4
ENTER
5 .
7. The Fader will then display\ 7 CRITERIA ",
which indicates the decision criteria for drawing an
M-Curve. Press 4
ENTER
5 and use the 4
85
arrow key
to toggle through the options: ALARM, 1E-3, 3E-4,
1E-4, 3E-5, 1E-5 and 1E-6. Unless you have opted to
use the ALARM INPUT to make the measurement,
select one of the other criteria and press 4
ENTER
5 .
8. The display will then read \ 8 SPEED ". This applies
only to Dynamic M-Curve, and will b e ignored for
Static M-Curve measurements. Press 4
95
to moveto
the next feature.
9. The display will now read \ 9 DEVIATION ". This
applies only to Dynamic M-Curve, and will be
1-8

HP 11757B Digital Radio Testing
ignored for Static M-Curve measurements. Press 4
95
to move to the next feature.
10. The display should then read \ 10 EDGE ZOOM ".
This feature increases measurement resolution near
the edges of the measurement, but will only b e
activated if you have sp ecied at least 15 data p oints
(we specied just 11 earlier in this example). Use
the 4
95
key to move to the next feature.
11. The display will now read \ 11 MK SEARCH ".
This algorithm will initiate worst case searches
during the measurement. For a full description see
MK SEARCH in the Lo cal and Remote Reference
Manual. Since this feature can increase measurement
time press 4
ENTER
5 to ensure that it is set to OFF,
then press 4
ENTER
5 again.
12. The display will now read \ 12 DFM TYPE ". This
allows selection of the type of DFM calculation
performed. For a full description see MEAS in the
Local Reference. The measurement setup is now
complete. DFM TYPE is only available in serial
prexes 3215A and ab ove.
Measurement
You are now ready to make the actual measurement.
Press 4
MEAS
5 . The display will indicate that the
measurement is in progress. When the measurement
has nished, the display will return to normal. If you
press the 4
PRESET/LOCAL
5 key on the Fader front panel
during the measurement, the measurement will b e
interrupted and stop.
Printing Results
1. After the measurement has b een completed, you can
print the results. First, set the printer destination.
Press 4
SHIFT
54
MEAS
5 (PRINTER), then use the 4
85
arrow key to select between 1 DEST and 2 PRINT .
Press 4
ENTER
5 on 1 DEST to set the destination.
Use 4
85
to select b etween EXTERN and INTERN .
1-9

Digital Radio Testing HP 11757B
Press 4
ENTER
5 on INTERN to set the printout for the
internal thermal printer.
Note
Once the destination has b een set, you do not need to
reset it b efore every printing. NONE is the PRESET
setting.
2. Next, print the parameters. Press 4
SHIFT
54
MEAS
5 , then
toggle the 4
85
key to get 2 PRINT . Press 4
ENTER
5 . Use
the 4
85
key to display PRVIEW , the press 4
ENTER
5 .
The printer will print the parameters you used to
make the measurement.
3. Next, print the data (graphic results). Press 4
SHIFT
5
4
MEAS
5 , then toggle the 4
85
key to get 2 PRINT . Press
4
ENTER
5 . Use the 4
85
key to display DATA , then press
4
ENTER
5 . The printer will now print the results.
1-10

HP 11757B Digital Radio Testing
Dynamic M-Curve
Measurement
Equipment Setup
1. The basic setup for all measurements involves
interrupting the IF path of the digital radio with a
fading simulator. If a Bit Error Rate Tester (BERT)
is used, connect the appropriate data channels. In the
gure below, the DS3 data out from the BERTis
connected to the DS3 input of the transmitter, and
the BASEBAND output of the receiv
er to the DS3
data input of the BERT. The ERROR OUTPUT
of the BERT is connected to the ERROR PULSE
INPUT of the Fader. This input can b e set to matc
h
the imp edance of the BERT.
Note
Some digital radios have their own error outputs and
internal data checking schemes that limit the need for
a BERT. See the manual for your radio if you wish
to connect the ERROR PULSE INPUT of the Fader
directly to the radio. There may b e a connection that
must be made b etween two p orts of the radio system for
this to work.
2. The RF output of the transmitter is connected to the
RF input of the receiver. Appropriate attenuation is
used to protect the RF input of the receiver. Check
the manual of the receiver and the transmitter to
insure safe levels for the receiver input.
3. The Alarm Output on the receiver can b e connected
to the Alarm Input on the Fader. This connection is
only needed for recovery tests, and tests where no
BERTisavailable and you want to use the ALARM
INPUT to indicate failure.
1-11

Digital Radio Testing HP 11757B
Figure 1-2. Dynamic M-Curve Measurement Test Setup
4. Connect the Fader, BERT and Digital Radio as
shown in gure 1-2.
5. Press 4
MEAS TYPE
5 . Use the 4
85
key until the display
shows DYNM M , then press 4
ENTER
5 .
Radio Setup
1. Press 4
RADIO SETUP
5 .
2. The rst item displayed reads 0 BIT RATE . Press
4
ENTER
5 to see what the bit rate is set to. The
preset value is 44.7 MHz (DS3). If you want to set
another bit rate use the arrow or data keys and press
4
ENTER
5 .
3. The display then reads 1 ERROR TERM . Press
4
ENTER
5 to nd the present setting. Use the 4
85
key
to toggle to the termination appropriate for y
our
BERT, then press 4
ENTER
5 .
4. The display then reads 1.1 ERROR THR . Press
4
ENTER
5 to see what the variable error threshold is
set to. If you want to set a dierent threshold use
the arrow or data keys. Choose a threshold setting
(combined with the ERROR TERM setting) that
is appropriate for your BERT, then press 4
ENTER
5 .
1-12

HP 11757B Digital Radio Testing
Error pulse input variable threshold is only available
in serial prexes 3235A and ab ove.
5. The display next reads 2 ALARM POL .You will not
need to set this unless you are planning to use the
ALARM INPUT for this test. Press the 4
95
key to
advance to the next feature.
6. The display should read 3 SCALE FACT . The
PRESET scale factor is 1, and this should only b e
changed if your BERT's error output is sending out
error pulses at a rate other than it is detecting them.
For instance, if the error output of your BERTis
sending one pulse for every four errors, set the scale
factor to four. To set the scale factor press 4
ENTER
5
when 3 SCALE FACT is displayed, then use the 4
85
arrowkey to display the factor your want, then press
4
ENTER
5 again.
7. The display should now read 4AGC ON/OFF .AGC
(Automatic Gain Control) maintains the p ower level
of the sp ectrum sent through the Fader. You may
want the p ower level to remain constanteven though
a notchissweeping through the band. If you are
interrupting the digital radio after its own internal
ALC or AGC circuitry,you mayhave to use the
Fader's internal AGC circuitry to prevent non-fade
eects from distorting measurement results. Press
4
ENTER
5 , then use the 4
85
key to displayAGC ON if
AGC OFF is displayed. Press 4
ENTER
5 to exit.
8. The display should now read 5AGC FREQ . If the
AGC is ON, you should ensure that you have the
proper AGC center frequency set. Press 4
ENTER
5
and the display will change \ AGC FRQ 070.0 "or
whatever frequency mayhave b een set previously.
Use the arrow or data keys to set the desired
frequency, then press 4
ENTER
5 .
9. The display should now read \ 6AGC BW ". This
allows you to set the bandwidth to distribute the
1-13

Digital Radio Testing HP 11757B
AGC p ower over. Press 4
ENTER
5 to see what value
this is set to. Use the arrow or data entry keys to
set a value. Use a value close to the radio's channel
bandwidth, then press 4
ENTER
5 .
10. The display should now read \ 7WAIT TIME ". This
allows you to set the wait time after every notch
movement. This wait allows your radio some settling
time b efore a Bit Error Rate measurement is made
by the Fader. Press 4
ENTER
5 to see what value this is
set to. Use the arrow or data entry keys to set a new
value if desired, then press 4
ENTER
5 .
11. The display should now read \ 8 MAX SLEW ". This
allows you to set the notch's maximum slew rate
during measurements. Press 4
ENTER
5 to see what
value this is set to. Use the arrow or data en
try keys
to set a new value if desired, then press 4
ENTER
5 .
12. The display should now read \ 9 SYMBL TIME ".
This allows you to set the symbol time of your radio.
You will not need to set this unless y
ou are planning
to p erform a CCIR DFM calculation. The radio
setup is now complete. CCIR DFM is only available
in serial prexes 3215A and above.
Measurement Setup
1. Press 4
MEAS SETUP
5 . This will access a series of
parameters to enter to set the Fader up for a
measurement.
2. The rst item displayed under 4
MEAS SETUP
5 is \ 0
DATA PTS ". This sp ecies the numb er of linearly
spaced frequencies to calculate and measure in the
band you have selected. Press 4
ENTER
5 to access, then
use the arrow or data keys to enter a value, then
press 4
ENTER
5 to get the next parameter. 11 is a go o d
value to enter to keep the measurement time down.
3. The second and third items will b e \ 1 STRTFRQ "
and \ 2 STOP FRQ ". These access the start and stop
1-14

HP 11757B Digital Radio Testing
frequencies for the notch. Press 4
ENTER
5 to access
STRTFRQ, then use the arrow or data keys to set a
value in MHz (use 50 for this example), then press
4
ENTER
5 . The display should show 2 STOP FRQ .
Press 4
ENTER
5 and set a value using data or arrow
keys (95 for this example), then press 4
ENTER
5 .
4. The next two items displayed are \ 3STARTRATE "
and \ 4 STOP RATE ". These parameters are used
for S-Curve measurements and will b e ignored when
making M-Curve measurements. Press 4
95
until the
display reads \ 5 ERROR BITS ".
5. ERROR BITS determines the number of errors that
are counted b efore a nal bit error rate calculation is
made. You mayenter p owers of 2 from 2 to 15 (4 ,
8, . . . , 32768). Press 4
ENTER
5 to access and use the
4
85
arrow key to get 2
11
, which equals 2048. Press
4
ENTER
5 .
6. The next displayed item is \ PHASE ". Press 4
ENTER
5
and use the 4
85
arrow key to select between the three
options: MIN, NON-MIN and BOTH . When b oth is
displayed, press 4
ENTER
5 .
7. The Fader will then display\ CRITERIA ", which
indicates the decision criteria for drawing an
M-Curve. Press 4
ENTER
5 and use the 4
85
arrow key
to toggle through the options: ALARM, 1E-3, 3E-4,
1E-4, 3E-5, 1E-5 and 1E-6. Unless you have opted to
use the ALARM INPUT to make the measurement,
select one of the other criteria and press 4
ENTER
5 .
8. The display will then read \ 8 SPEED ". This
parameter determines the peak frequency p er second
at which the notch oscillations will take place for
Dynamic M-Curve measurements. Press 4
ENTER
5 to
access. Sp eed is entered in megahertz per second.
The PRESET is 300 MHz p er second. Use the 4
95
arrowkey to toggle b etween the allowable values: 10,
1-15

Digital Radio Testing HP 11757B
30, 100, 300, 600 and 1200 MHz per second. Cho ose
avalue and press 4
ENTER
5 . Refer to gure 1-3.
9. The display will now read \ 9 DEVIATION ". This
refers to the maximum deviation of frequency the
notch will take as it makes a measurement. See
gure b elow. Use the arrow or data keys to select a
value ( 6 1, 6 2, 6 4, 6 6, 6 10 and 6 20 MHz). Do not
set a value that will cause the starting or stopping
frequency for your measurement to exceed allowable
bounds. For instance, if you set the start frequency
at 45 MHz, and set the deviation at 6 20 MHz, an
error message will result (45 0 20 = 25, and 25
MHz is below the minimum frequency for Fader).
There is a guardband of 6 4 MHz that should b e
used to prevent errors. The formula for calculating
acceptable deviation values is:
START FREQ 0 ( j DEVIATION j +4 MHz)  40
MHz
STOP FREQ +( j DEVIATION j +4 MHz)  100
MHz
Use the arrow keys to set 6 5 MHz, then press
4
ENTER
5 .
1-16

HP 11757B Digital Radio Testing
Figure 1-3. Speed and Deviation
10. The display should then read \ 10 EDGE ZOOM ".
This feature increases measurement resolution near
the edges of the measurement, but should only b e
activated if you have sp ecied at least 15 data p oin
ts
(we specied just 11 earlier in this example). Use
the 4
95
key to move to the next feature.
11. The display will now read \ 11 MK SEARCH ".
This algorithm will initiate worst case searches
during the measurement. For a full description see
MK SEARCH in the Lo cal and Remote Reference
Manual. Since this feature can increase measurement
time press 4
ENTER
5 to ensure that it is set to OFF,
then press 4
ENTER
5 again.
12. The display will now read \ 12 DFM TYPE ". This
allows selection of the type of DFM calculation
performed. For a full description see MEAS in the
Local Reference. The measurement setup is now
complete. DFM TYPE is only available in serial
prexes 3215A and ab ove.
1-17