Tektronix 11A34 Owner's manual

TEK
User3 Reference Part No. 070-5921-00
-,_
Supplement Product Group 47
llA34
Four Channel
Amplifier
Serial Number- -
Please check for CHANGE INFORMATION in the rear of this manual.
-
First Printing FEE 1987
RevisedOCTi987

-
.
<
. . .--..e -m.-.. .
TEK .INTER-OFFICE COMlvllJNlCATlON.-
.
Sohn Martin 94-540
TO 3:.'t Juno 25, 1991
FWW
Frank Gray, SO-PAT
M3KC.T
GIDEP permit request
In response to the request to grant permission to the
Government Industry Exchange Pro ram
Tektronix operator, service and P
(GPDEP) to reproduce
nstruction manuals,
Tektronix, Inc. hereby grant6 such permission for distribution
of such documents to any GTDEP user that is a full participant
in the Metrology Data Interchange Data Base of GIDEP provided
that all copies of the original work include the entire
copyright notice and ownership statement exactly a-&it appears
in the original, together with the Legend "Reproduded with
pemieeion,a
This permission has been approved by the Intellectual
aeon% 1[
Committee of Tektronix
ded
and a copy of this memo may
to GIDEP to provide'the requested permission.
g:&dy
Group Pat&t Coun&al

INSTRUMENT SERIAL NUMBERS
Each instrument has a serial number on a panel insert, tag, or stamped on the chassis. The firat number or
letter designates the country of manufacture. The last five digits of the serial number are assigned sequen-
tially and are unique to each instrument. Those manufactured in the United States have six unique digits.
The country of manufacture is identified as follows:
B000000
100000
200000
3aoooo
700000
Tektronix, Inc.. Beaverton. Oregon, USA
Tektronix Guernsey. Ltd., Channel Islands
Tektronix United Kingdom, Ltd., London
Sony~ektmnix, Japan
Tektronix Holland, NV, Heerenveen, The Netherlands
CopyrightQ Tektronix, Inc.. 1987. All tights resewed. Tektronix products are covered by US. and foreign
patents, issued and pending. TEKTRONIX, INC. SCOPEMOBILE and are registered trademarks.
Printed in U.S.A.

llA34 Features and Functions
Feattues
.
Dual trace
Up to 300 MHz bandwidth (in 114M)
Calibrated sensitivities from 1 mV to 10 V/division
5lX2 or 1 MR input impedance
High-resolution, calibrated DC offset (0.25 division/increment, coarse; 0.025
division/inoement, fine)
Fast ovwdrive recovery
FUllCtiOllS Signals applied to the CH I, CH 2, CH 3 and M 4 input co~ectors can be
displayed or removed from the display by pressing the display on/off buttons
adjacent to the input connectors.
All other llA?A functions are conkoUed through the host mainframe. Such
ontrolled func!ion5 are:
9 Sensitivity, Coarse and Fine, over a range of 1 mV to 10 V/division.
l verticaloffset
l Coupling: AC, DC, or Off.
l Impedance (input termination): 5On or 1 MC&
l Bandwidth Limit: 100 MHz or 20 MHz
l Display Polarity: normal or inverted
l Trigger Polarity: normal or inverted.
l Combination of Display Channels: see Operating Information section of
mainframe User’s Reference manual.
lCombination of Trigger Channels: same as Display Channels; zee Operating
InfontWion section of mainframe User’s Reference manual.

Contents
Part l-General Information
Technical Manuals ....................................................................................................... l-l
Contents ofthis Supplement ................................................................................. 1-l
1 IA34 Service Manual ............................................................................................ l-2
Plug-in to Mainframe
Compatibility ........................................................................ l-2
hitiel tmp&ion
.......................................................................
*.
.................................
l-2
Operating Temperature .............................................................................................. 1-3
Installing and Removing the llA34 .......................................
+. ................................. l-3
Irlstrument options .....................................................................................................
14
Packaging for Shipment .............................................................................................. l-5
Part 2-Operatig the llA34 in 11301 and 11302 Mainframes
Display On/off .... _*. ................................................................................................... 2-l
S&ding Coupling. HF Limit, and Impedance ....................................................... 2-l
Other Functions ..............................................
. ............................................................. 2-2
Position and Offset ...................................................................................................... 2-2
HFLimit ........................................................................................................................ 2-3
DC Ciit Loading ..................................................................
. .................................. 2-3
Adding Waveforms ..................................................................
.
..................................
24
overdrive Recovery .................................................................................................... 2-4
5OfI Overload
.................................................
*. ............................................................ 2-7
Active Probe.
............................................................................................................... 2-7
Probe II3 ........................................................................................................................ 2-7
FronH’anel Error Messages ....................................................................................... 2-8
GPIB and -232-C Commands and Syntax .......................................................... ..2- 9
Part 3-0perating the llA34 in 11401 and 11402 Maiaframes
Display On/Off
..
.._ .............. . ......................................................................................
.3-l
Other Functions ............................................................................................................ 3-l
Vertical Offset ............................................................................................................... 3-2
BW Limit .............. *.....-....- ^ .
...... .
..
. ... .
.........................
..- ....................................
3-2
DCCircuit Loading
,._
.......................................... *..................................................... 3-2
Ad&g and Subtracting Wavefoti .................................................. +.
...................
.3-4
overdrive Recovery
................
.
..
................. .. .
.
... ..... .
..........................................
3+5
5On Overload ....................................................................................... ..*. .................... 3-a
Active Probes
................................................................................................................
3-8
Robe rD ...................... _*. .._ ............ ...”
.
. .
.
. . . ............................................................ 3-8
Front-Panel !&or Messages .................................................................
.
..................
.3-10
GlTB and lGGJ32-C Commands and Syntax.......................................................... 3-11
Part P-Specification
Performance Conditions ............................................................................................. 4-1
Electrical Characteristic3
.............
.
......................................................................... .4-l
Environmental Qlsracteristics .............................................................................. 4-7
Physical Characteristics.......................................................................................... 4-a
Recommended Probes
....................................
..fl........................................................ 4-8
11 AZ4 User’s Reference Supplement
RM JUL 1987 llA34 i

L
Appendix A-Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-l
Appendix B-hstrument Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1
Illustrations
l-l
2-I
2-2
2-3
3-1
3-2
3-3
34
4-1
Installing a plug-in unit in a mainframe oscilloxope ,a..< tt.tt.t.t..t.t..tttl,..,.,,,., I-4
I.
Location of AC coupling capacitors in plug-in amplifiers . . . . . . 2-3
Overdrive recovery using long (top) and short (bottom) cables
terminated in SOR. Traces ore offset two divisions and the
photograph is a double exposure .,,....,...,,....................................................... 2-5
c
Overdrive recovery using long (top) and short Coottorn) cables
uriterminated. Traces are offset ,hvo divisions and the photograph
is a double exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..~................. 2-6 I
Location of AC coupling capacitors in plug-in amplifiers . . . . . . . . . . . . . 3-3
Overdrive recovery using short (top) and long (bottom) cables
terminated in 50~2. Traces are offset two divisions and the
illustration is acomposite of two waveforms
e
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Overdrive recovery using short (top) and long (bottom) cables
-I
unterminated. Traces are offset two divisions and the illustration
is a composite of two waveforms .t....t.t....tt........,..,,.,.,,.~........,.,,...... + t...tt.l..t.... 3-7
Sequence of decisions used to select a new waveform in response
toprobe ID button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Dimensions of llA34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Tables
2-l Functions AndWhere They Are Described .................................................. .2-2
3-l Functions AndWhere They Are Described .................................................. .3-l
4-l Rlectrical Characteristics .................................................................................. .4-l
4-2 Environmental Characteristics ......................................................................... 4-7
4-3 Physical Characteristics.....................................................................................
4-8
ii llA34 REV OCT 1987
llA34 Lker’s Reference Supplement

Illustrations
l-l
2-1
2-2
2-3
3-l
3-2
3-3
34
4-1
5-1
Tables
Installing a plug-in unit in a mainframe osdllosope . . . . . . . . . . . . . . . . . *._ .+.... t . . . . 14
tocation of AC coupling capacitors in plug-in amplifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Overdrive recovery wing long (top) and short (bottom) cables
terminated in Mfi Traces are offset two divisions and the
phomFaph is a double exposure ..__.._.._...........................................l.............. 2-5
Overdrive recovery using long (top) and short (bottom) cables
unterminated. Traces are offset two divisions and the photograph
is a double exposure . . . . .._...._ _ ._.. _ . . . . . . _ . . ..._._.._.._.._._................................~............. 26
Location of AC coupling capacitors in plug-in amplifieft ._......................... 3-3
Overdrive recovery using short (top) and long (bottom) cables
terminated in 5OR. Traces are offset two divisions and the
illustration is acomposite of two waveforms . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Overdrive recovery using short (top) and long (bottom) cables
unterminated. Traces are offset two divisions and the illustration
is acomposite of two waveforms . . . . . . . . . . . . . . . ..._.................................................. 3-7
Sequence of decisions used m select a new waveform in responw
mprobe ID button..... . . . . . . . . _ .._...._.,....._.................. _ . . . . . . . . . . . . . . . . . I . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Dimensions of llA34 . .._...._._. _ _............_.._._...........................................,.... I ,....... 4-9
Input disconnect time and threshold waveform ,............._.._....................... 5-14
2-1
3-1
4-l
4-2
4-3
5-l
Functions And Where They Are Dezrikd ................... .
............................... 2-2
Functions And Where They Are Described ................................................... 3-l
Electrical Chafacteristics ................................................................................... 4-l
Environmental Characterisrics ......................................... . ............................... 4-7
physical characteristics .................................................................................. ...4-a
Test Equipment Required ................................................................................. 5-1
11X34 User’s Reference Supplement
nA34 iii

Part 1
General Information
Technical Manuals
‘his Supplement to the mainframe User’s Reference manuals and the Incoming
Inspection Procedure manual are standard accessories to the IlAX
For a list of
dated manuals, see Appendix B.
Contents of this Supplement
This Supplement contains the following five park
Part I-GENERAL INFORhJATION, de&W mainframe to plug-in unit
compatibility, explains how to install and remove the llA34 from a
mainframe,outinesany options available for the llA34, and gives details
about packaging for shipment.
Most llA34 functions, and their use, are d&bed in the Operating Information
section of the mainframe User’s Reference manuals. These functions are common
to all amplifier plug-in units. Examples of common functions are offset,
sensitivity, input impedance (where selectable), coupling. and bandwidth
limit. Only functionsuniquetothe11A34-11301/11302or11A34-11401/11402
combinations are explained in the following parts.
Part Z-OPERATING THE llA34 IN 11301 AND 113X MAINFRAMES,
explains how to operate those: llA34 functions not covered in the 11302 User’s
Reference manual.
Part3-OPERATINGTHEllA34IN11401AND114MMAINFRAMES,
explainshow tooperatethose llA34func!ionsnot covered in the 11401 and
11402 User’s Reference manual.
Part 4-SPECIFlCATION, gives detailed specifications of all llA%
mainframe oscilloscope combinations.
11 A34 User’s Reference Supplement
REVccri987
llA34 l-l

1 lA34 Service Manual
The 1 lA34 Semi% manual isfor use ty qua&d m&e personnel
only. Toamidpmsonalinjuy, do notperform myserkceother
‘than that contnined in the Operators manual unless you are
qulifialto aoso.~tOthe~torsSafety~ummarynlld
&mice Safely Summa y befDre performing anyservtw.
The 1 1M4 service manual contains the f0110wing information:
Se&on 14ENER4L INFORMATION.
Section 2-THEORY OF OPERATION.
Section S-MAINTENANCE AND lX4GNOSTIcS.
Section 4-PERFORMANCE VF+XXATION AND ADJLEIMENT.
SacdonS-INSTR-
OM’IONS.
Section &REPLACEABLE EJBZTRKAL PARTS.
Section 7-SCHEMATIC DIAGRAMS AND CIRCUIT WARD
ILLUSTRATIONS.
!Seciion &REPLACEABLE MECHANICAL PARTS.
Plug-in to Mainframe Compatibility
The11A34isd~ignedforuseinthe11301,11302,11401,11402,andfuturell~
series plug-in mainframes. 1
lA+ bandwidth varies depending on the host
mainframe. Details about bandwidth are included in Part& Specification, of
this Supplement, and in the Tektronix Corporate Catalog. Refer to the
Tekbonix Corporate C&lag for complete compatibility information.
Initial Inspection
This instrument was inspected mechanically and elecwically More shipment.
It should be free of mars or scratches and should meet all elech-ical
specifications. First, inspect the 1lAX for physcial damage incurred in transit.
Secondly, to verify that the instrument is functioning properly, perform the
Incoming Inspeclion Procedure, shipped with the instrument. This brief
procedure verifies nrose instrument functions and checks the internaY autc-
calibration references. If you find inwwnent damage OF deficiency, contact your
local Tektronix Field office or representative.
I-2 llA34
REVOCT 1987
Part 143neral Information

Operating Temperature
ThellA34eanbeoperatedwheretheambientairtem~hrreisbetweenO”
and twc and can be stored in ambient temperature3 from 4P to t7sT. After
storage at temperatures outside the operating limits, Aow the chassis to reach
opratixtg temperature hits More applying power.
Installing and Removing the llA34
To awid instrument dmmgc set the mainframe ON/STANDBY
switch to STANDBY b&einstaUingorremving the llA.34.
rffhEgw.m indbrator fight remzim ON, when the STANDBY
posiiiot~ is selected, themitch bps been intentaay d*rbkd.
Toremove or reimfdl plug-in unii$, use the mainframe
PRlNC.lPALPOWRSWlTCH~rar~~ toshutOfFthe
pwr. Thk wdl pwoent damage to dth.9 the plug-in or the
IMit4frmnc.
To onceap’n enable the ON/STANDBYm’tch, r&the
imAt to qua&d Seroice~Rml.
When in5taUed inany 11401/11402 plug-in comparbnent, or in the i1301/11302
left or center plug-in compartment, the 1 IA34 will provide a conventional
display.
When in5iaUed in thecenter or right phig-incompartment of the 11301/11302,
the 11.43-i will ako provide theX (horizontal) part of an X-Y display, or
provide a tigger signal for the mainhame time base.
Toinskdl thellA34inanytlWOseriesosdlloscopemainframe,set the
mainframe ON/STANDBY stitch to STANDBY. Align the grww in the tap
and bottom of the llA34 with the guides in the mainframe plug-in
compartment, then b3-t the 111334 into themainframe until its front panel is
f&h with the front panel of the mainframe.
To remve the llA?A from a meimbme, Set the maikame ON-=ANDBY
switch to STANDBY. Then pull the release latch be fig. 1-I) to disengage
the unit from the IT Cnfmme, and pull the 11.434 stmight out of the plugin
compknent
IL434 U&s p.eference Supplement

Installing and Removing the llA3
Figure 1-I. Installing a plug-h unit in a mainframe oscilloscope.
Instrument Options
Option 23 indude four P6134 probe%

Packaging for Shipment
lf this inshwment is to be shipped by commer&l transportation, we recommend
that it be packaged in the original manner. The ori@ carton and packaging
material can be saved and reused for this pu’p~se+
NOTE
Puckiagennd ship plug-in units rind muinfrmncs sepnmtely.
If the llA34 is to be shippad to a Tekaonix Service Center for service or repair,
al-hch a tag to the insirumen~ On the tag. include the following information:
l Name and address of the instrument owner;
. Name of a person at your firm who can ba contacted about the instrument;
l Complete instntrnent type and serial nun-&r, and
l A da=cription of the service quired.
If theori@nal package isnot available or is not fit for use, package the IL434
as follows:
1.
2.
3.
4.
5.
Obtain a corrugated cardboard carton with inside dimensions at least six
inches greater than the iwtmnent dimensions. Use a carton with a test
strength of at least 2M) pounds.
Fully wrap the ltA34 with snti-s!atic sheeting, or its equivalent, to
protect the finish.
Cushion the llA24 on all sides by tightly pa&ng dunnage or urethane
foam between the carton and the instrument. Allow thrfx inches of
packing on each side.
Seal the carton with shipping taupe or with industrial staples.
Mark the address of the Tektmnix service Center and your rehw address
on the carton in one or more prominent places.
llAZ4 U&s Reference Supplement

lf301 ad 11302 Mainframes
Display On/Off
The llA34 has only four front-panel contmols-the display on/off buttons.
Pressing a display on/off button will cause its chamwL and signal, to be
displayed or removed from the display (the function “toggles”). When a
channel is displayed, its label ((311, Cl-I 2, CK 3, or CH 4) will be lighted.
Selecting Coupling, HF Limit, and Impedance
To select the desired setting for Coupling, FIF Limit, 0~ Impedance, proceed as
follows:
la.
lb.
2.
3.
If no trace is displayed, pre55 any plug-in display on/off button to create a
h-ace.
If several traces are diiplayed, select a channel by touching the desired
trace description at the top of the at.
Press any VERTICAL button--OFFSET, SEE, or PG. This button-pre%
will cause the Control Menu to be displayed.
Touch the desired function’s label. Successive touches will change its
state.
llA34 User’s ReferenceSupplement nA34 2-1

Other Functions
Ohs ~~?4functi011~amcontrolledwithin the 11301 or11302mainframe,and
their operation is described in detail in Section 2, Operating Information, of the
11301 andl1302User’sReferencemanual. Table2-1 showswhereto hd
informationabout operatingthe llA34.
TABLESI
Functions And Where They Are Desa-ibed
Function
of-k&
size W/div)
Displaytil,Kh2
Sh3,kaI4
Desaibed Under Heading
Waveform Acquisition: Vertical Menu;
or for X-Y Display: Horizontal Menu.
Waveform Acquisition: VerticaI Menu.
Polarity
Wavef~nn Acquisition: Waveform Menu.
Trigger Selection Trigger Source Major Menu and Polarity
Position and Offset
The 11301 and 11302 osci~oscopes assign position control to the Left Control
knob by pressing the VERTICAL MS button. The Vertical Position control
moves the trace as a user convenience. For example, when displaying multiple
channels it may be desirable to set ground references for each trace on separate
graticule lines Position is a screen-related function; its units are divisions.
The offset function, accessed by pressing the VERTICAL OFFSET button,
subtracts a predsion voltage from the ‘input signal. Changing offset mattes the
trace just as does the position control. However, if the deflection factor is
subsequently changed, the effect is different
Changing the sensitivily will increase pr dwrease the size of the display
around some - level kg., two divisions above graticule center) set by the
Position control. When using a sensitivity that makes the displayed waveform
larger ti-m the screen, theOffset control is wed to bringthe waveform area of
interest to the screen location established by the Position control.
The Position control has a range of plus and minus four divisions from graticule
center, but the Offzut con!rol has a range defmed in volts. Of&t can be as much
as loo0 divisions at 1 mV/division. The Offset control range is one volt for all
sensitivities from 1 mV to 995 mV/division, but ina-eaees to 10 volts for
sensitivities from 100 mV to 995 mV/division. For ~~@+&es from 1 volt to 10
volt5/diMon, Offset control range in-se5 to IOD volts.
2-2
lIA34 Part2--OperathgthellA34in113o1and 11302Mailhames

Position and Offset
The llM4 attempts to maintain the user-selected offset volwge even though
theoffset rangechangesduetoachangeinsensitivity. Anoffsetvoltageof less
than one volt will be maintained as the sensitivity is changed over the entire
range of 1 mV/diWon to 10 V/division. A skcted offset of greater than one
volt is beyond the offset range for the most sensitive settings and will be reset to
one volt when the sensitivity is increased to any value between 995 mV and
1 mV/divisioh
HF Limit
Two four-pole (24 dB/octave) bandwidth Limit (lowpass) filters are available
for each llM4 channel. The purpose of the filters is to reduce the amplitude
of unwanted noise of inteference occurring at freqwncies above the frequency of
the signal of interest. The user has a choice of cut-off (-3 dB) frequencies,
either 20 MHz or 100 MHz, independently for each charmel. The bigger,
auxiliary trigger, and display signal bandwidths for a channel are always the
came The aludliary bigger is the signal Sent to the right plug-in compartment.
DC Circuit Loading
AC coupling capacitors are conneckd differently in the tlA52 and llA7l than
in the ltA32 and llA.34. Figure 2-l shows this difference.
Figure 2-l. Location of AC couptig capacitors in plug-in amplifiers.
1lAN user’s Reference Supplement
llA34 2-3

Intha llA52and llAn,therouplingcapadtorisolatffboththeinput
termi~tion end the amplifier from external dc voltages. However, the
muplingcapadtorinthellA32and llA3pdoesnot.
Adding Waveforms
E$xeaddingwau+~,chxkthatea%&annel’s
dkplsy is independently on screen.
The 11301 and 11302 allow the addition of any two channels. That is, one
channel may be added to a channel from another plug-in unit A simple
re3tiiction applies. Each channel must bs in its liiear operating range. This is
assured if each channel separately is within the WW-I area before addition.
Those ptions of a trace which are off screen will not be valid when brought
back on m using another channel3 input signal or Offset control. This
geneml ~~tric!ion applies to any duakhanne1 osdlloxope.
Overdrive Recovery
Ovardriveoccurs whenany llA34channel isdrivenoutof itslmearmngeof
approximately ‘15 divisions.
The 11A34 hes extraordinarily good overdrive recovery, and this feature may
be wed to greatly extend measurement resolution. For example, suppose a signal
changesfrom-1.7Vto+O.8Vin1ns.ThellAS4couldbeusedtodetermineif
the signal stabilized immediately at +0.8 V or if perhaps had some small

1
aberration following the tzansition. By setting the llA34 offset to 4.8 V and
I
the sensitivity to 1 mV/division, aberrations of just 0.1% of the ori@nal
hansition will be 25 divisions in amplitude (0.1% of 25 V is 25 mV or 25
divisions at 1 mV/division).
Anyamplifierwiu ultimately reach anequilibti~vabt~ irft~rirn
hkhough 3s accuracy will determine how far that equ
the came3 value). The IlAWsability to settlequickly to within9
fraction of its equilibrium value is exceptional. The time it takes
settle to within a stated fraction of the equilibrium value is its overdrive
rec0”ely time.
Measuring the overdrive recovery time of an llA34 takes ~rne care and can
lead to some surprising results. An interesting experiment is to use a very flat
puke generator, such as the Tektronix FG 506, to puke the llA34. Connect the
generator’s fast-r&output to the llA3l input througha short (one foot or less)
coaxial cable and sel& 5m input impedance. Adjust the pulse amplitude to 1
volt Set the 1lAZ-l sensitivity to 1 mV/division. Each division now represents
0.1% of the input signal. Trigger the osdlloscope and observe the recovery of
the llA34 using 50 ns/division sweep rate. Now iraeaee the cable length by
about three feet (for example, use a 424nch length of RG58 cable, Tektronix
part 012435701) and observe the new waveform. See Figure Z-2.
Figure 2-Z Ovesdrive recovery using long (top) and short (bottom) cables
terminated in 5on Traces are offset two divisions and the photograph is a
double exuosrue.
1 IA.?4 User’s Reference Supplement
ll.434
2-5

Overdrive Recovery
The waveform cbmge is due to skin effect loss in the longer cable. What is
surprisingis~tt~sklneffectlosspersis~forover2M)nseventhoughthe
total cable delay is only 5 ns. At 4W 11s the loss is still 0.02%.
This experiment shows tba importance of using a short cable to test overdrive
RC0Vel-y.
A second surprise is that skin effezt loss disappears almost completely (after
two cable delays) when one end is unterminated.
To observe this, use the short cable again, and selwt 1 hK? input impedance on
the llA34. Insert a 7X attenuator between the cable and the pulse generator to
improve the reverse termination and to provide the same amplitude signal as
before. Observe the -I-LX and change obles again. Even at 0.1% per
division the skin effect loss is hard to detect without the forward termination.
The reason for this is that the skin effect loss is an increase in the efktive
series resistance of the cable.
voltage drop. see Qure 23. Without current, the cable develops no series
Figure 23. Overdrive recovery using long (top) and short (bottom) cables
unterminated Traces are offset two divisions and the photograph is a double
exposure.
2-6
llA34

When the input impedance is set to 5CQ and the input voltage substantially
aceeds5 Vrms, the llA34 wiII sense the overload, disconnect the 5oR input
termination, and comezt the 1 MQ termination. ‘Ihe Impedance menu will show
1 MQ and the mainframe will disptay the message: “Input charmel N overload
on LEIT/CENTER/RIGm plugin,” where N = 1,2,3, or 4.
To reset the input impedance to 5ZQ first correct the overload condition, then
sekt 5CKl from the Impedance menu.
Active Probes
Using an active probe, such as the P6231, eliminates two options: A C Coupling
and 1 Mn input impedance. Coupling options available when using such a
probe are Off and Dc; the only Impedance available isx62.
Probe ID
The Probe ID part of the Utility Menu is tie means of selecting how the 11301
or 11302 responds to an ID button-push of recommended probes.
AIL or some
combination of the following operations may be set to start in response to probe
ID buttons. To display the Utility Menu, p- the front-panel UTILIlY button.
For details, see the Probe ID part of the Waveform Acquisition subsection in the
11301 and 11302 User’s Reference manual.
Prexingtheprobe ID buttoncaninitiateoneormoreof the following
opemtions
1. Present a new display, or if that cbarmel Is already displayed, %elecY
the existig trace pressing the ID button of a probe connected to an
undisplayed left or center compartment channel will cause that channel to
lx displayed, unkss doing ~0 would exceed the maximum number or traces.
Unlike the 1 IA?4 display on/off button, prrssing the probe ID button a
s-xond time will not remove the display. Probe ID button-presses for
displayed channels will do two things: a) sekt the trace(s) using this
channel, and b) momentarily brighten aII traces using this channel.
2. f oad setigs can be sequentially recalled Pressing the probe ID button
can cause a squentil rccalI of stored settings. The stored settings feature
mu% be enabled using the Probe ID Utility menu. Settings must be stored
asexplained underSTORE/RECALL Ma@ Menu in the 11301 and 11302
User’s Reference manual.
llA34 us&s Reference Suppkment 1w4 2-7

Probe ID
3.
4.
5.
e can”AutweY’ to accommodate the input signal introduced
geprobc TheAutosetfeaturewbeenabledordisabledusingthe
Probe ID Utility menu. Autos-et is the automatic setup of vertical
deflection factor, triggering and sweep speed to produce a meaningful
display, e.g., two to five divisions of vertical deflection and two to five
repetitions of the input signal. For more information, refer to Autoset in
the 11301 and 11302 User’s Referqrce manual.
The mainframe can automatically measure the selected trace. Automatic
measweme.r@ of the selected uace can ba initiated by pressing a probe ID
,button. The Automatic Meas-ana feature can be enabled or disabled
using the Probe ID utility menu. such xne asuremen~ are peak-topeak,
maximum, middle, and minimum voltages; frequency, period, pulse width,
and duty cycle. For full information about automatic measurements, see
Measure in the 11301 and 11302 User’s Reference manual.
An interrupt to the GPIB and M-232-C can be generated. Pressing a probe
ID button will cause the mainframe to produce an SRQ to the GLIB and Iis
232-C For more information, refer to the GlTE/RS3ZC part of the 11301
and 11302 User’s Reference manual.
Front-Panel Error Messages
Message:
Cause:
Message:
Cause:
Internal DAC overflow on channel N of LEFT, CENTER, or RIGHT
plug-in unit, where N = 1,2,3, or 4.
Some plug-in unit detected that a requested setting overflowed an
iHerml DAC. Such overflow usually indicates defective
hardware. Jn this situation, the plug-in unit sets the DAC to the
limit nearer the rquestecl setting.
BadLevef2probe t&e&urn
on chmd N of LEFT, mR, or
RIGHT plug-in unit, where N = 1,2,3 or4.
Some plug-in unit detected that a Level 2 TEKPROBE had failed
or ken improperly cormacted.
2-S
llA34 Part Z-Operating the llA34in 11301 and 11302 Mainframes