Tektronix 7A42 User manual

PRODUCT GROUP 42
070-4285-00
OPERATORS
MANUAL
Logic Triggered
Vertica Amp ifier
P ease check for change information
at the rear of this manua.
First Printing APRIL 1983
Revised JUL 1984
Tektronix
COMMITTED TO EXCELLENCE
TEK
7A42

7M2 Operators
TABLE OF CONTENTS
Page
OPERATORS SAFETY SUMMARY ............................................................................. vi
DESCRIPTION ............................................................................................................. viii
1
GENE AL INFO MATION
COLOR USED IN THIS MANUAL ....................................................... 1-1
TECHNICAL MANUALS ....................................................................... 1-1
OPERATORS MANUAL .................................................................. 1-1
SERVICE MANUAL ......................................................................... 1-1
INSTALLATION ........................................................................................... 1-2
INITIAL INSPECTION ........................................................................... 1-2
OPERATING TEMPERATURE ............................................................ 1-3
INSTALLING THE 7A42 IN THE MAINFRAME ................................. 1-3
MAINFRAME COMPATIBILITY .......................................................... 1-4
PACKAGING FOR SHIPMENT ............................................................ 1-5
SPECIFICATION .............................................................................................. 1-6
STANDARD ACCESSORIES ...................................................................... 1-24
OPTIONAL ACCESSORIES ........................................................................ 1-24
PROBES ................................................................................................... 1-24
2
OPE ATING INST UCTIONS
OPERATION ........................................................................................... 2-1
SIMPLIFIED BLOCK DIAGRAM OF 7A42 ..................................................... 2-1
BOOLEAN ALGEBRA FOR 7A42 USE .......................................................... 2-3
CONTROLS, CONNECTORS, AND INDICATORS ..................................... 2-9
GET-ACQUAINTED EXERCISES ............................................................... 2-13
EXERCISE 1 — PRELIMINARY SET UP AND INITIALIZATION ....... 2-13
PRELIMINARY SET UP .................................................................... 2-13
INITIALIZATION ............................................................................... 2-14
EXERCISE 2 — OBTAINING A TRIGGERED DISPLAY ...................... 2-16
EXERCISE 3 — LOGIC TRIGGERING .................................................. 2-36
DETAILED OPERATING INFORMATION ................................................. 2-48
SELF-TEST .............................................................................................. 2-48
FRONT-PANEL INITIALIZATION ........................................................ 2-52
BATTERY BACKUP ............................................................................... 2-52
OPERATOR MESSAGES ...................................................................... 2-54
SIGNAL CONNECTIONS ...................................................................... 2-56
RECOMMENDED PROBES ............................................................. 2-57
PROBE COMPENSATION .......................................................... 2-57
COAXIAL CABLES ........................................................................... 2-57
CRT READOUT ...................................................................................... 2-57
POSITION ............................................................................................... 2-59
GAIN ......................................................................................................... 2-59

7A42 Operators
TABLE OF CONTENTS (CONT)
OPERATING INSTRUCTIONS (CONT) Page
STATUS INDICATORS (CH1, CH2, CH3, CH4) ................................ 2-59
DISPLAY ............................................................................................ 2-59
ECL/TTL ............................................................................................ 2-59
GND ................................................................................................... 2-59
50Ω/1MΩ ............................................................................................ 2-59
ALT/CHOP .............................................................................................. 2-60
TRIGGER FUNCTION ............................................................................ 2-60
A TRIGGER FUNCTION AND B TRIGGER FUNCTION ............. 2-60
A THEN B NESTED TRIGGERING ................................................. 2-60
TRIG VIEW .............................................................................................. 2-61
TRIGGER FILTER ................................................................................... 2-61
EXT CLOCK SYNC ................................................................................. 2-61
SLOPE SELECT .................................................................... 2-61
EXT CLOCK INPUT .......................................................................... 2-62
RESET INPUT ........................................................................................ 2-62
TRIGGER OUT ...................................................................................... 2-62
PROG CHAN/TRIG ............................................................................... 2-64
PROGRAM CHANNEL MODE ........................................................ 2-64
CH1, CH2, CH3, CH4 ................................................................... 2-65
DISPLAY ...................................................................................... 2-65
TTL/ECL ...................................................................................... 2-65
VOLTS/DIV ................................................................................... 2-65
GND ............................................................................................. 2-65
1MΩ/50Ω ...................................................................................... 2-65
THRESH ........................................................................................ 2-65
PROBE OFFSET .......................................................................... 2-66
LEVEL ............................................................................................ 2-66
PROGRAM TRIGGER MODE .......................................................... 2-67
CH1, CH2, CH3 AND CH4 .......................................................... 2-67
AND ............................................................................................... 2-67
OR ................................................................................................. 2-67
CLEAR .......................................................................................... 2-67
NOT ............................................................................................... 2-67
EDGE ............................................................................................ 2-67
3
APPLICATIONS
APPLICATION 1 — DISPLAYING FOUR CHANNELS OF DATA
WITH THE 7A42 ......................................................................................... 3-1
MEASUREMENT TECHNIQUE ............................................................ 3-1
VIEWING THE MASTER CLOCK LINE ........................................ 3-2
APPLICATION 2 — SOLVING ABNORMAL PULSE PROBLEMS
WITH THE 7A42 ......................................................................................... 3-4
MEASUREMENT TECHNIQUE ............................................................ 3-4
jj REV JUL 1984

7A42 Operators
TABLE OF CONTENTS (CONT)
APPLICATIONS (CONT) Page
APPLICATION 3 — ADDING EDGE SENSITIVITY TO YOUR
TRIGGER FUNCTION ................................................................................ 3-6
MEASUREMENT TECHNIQUE ............................................................ 3-6
APPLICATION 4 — DETECTING AND DISPLAYING BUS
CONTENTION ............................................................................................. 3-9
MEASUREMENT TECHNIQUE ............................................................ 3-9
APPLICATION 5 — ENHANCED NESTED TRIGGERING USING
THE 7D15 225 MHz UNIVERSAL COUNTER/TIMER ....................... 3-11
EVENTS COUNTING ........................................................................ 3-11
COUNTING CLOCK CYCLES BETWEEN EVENTS ...................... 3-12
MEASURING TIME FROM FUNCTION A TO FUNCTION B .... 3-12
APPLICATION 6 — OFFSET PROBING TECHNIQUES FOR
HIGH SPEED LOGIC SYSTEMS .......................................................... 3-14
PROBING ECL CIRCUITS ............................................................... 3-15
7A42 PROBE OFFSET FEATURE ................................................... 3-16
APPLICATION 7 — USING THE 7A42 WITH THE 7854 ...................... 3-17
APPLICATION 8 — USING THE 7A42 WITH THE 7104 ...................... 3-18
4
INST UMENT OPTIONS
INDEX
CHANGE INFO MATION
ELATED DOCUMENTATION
For information on re ated 7A42 documentation referto Genera Information, Section
1 of this manua under Technica Manua s and Standard Accessories.

7A42 Operators
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LIST OF ILLUST ATIONS
Figure
No. Page
1-1 7A42 re ease atch ...................................................................................... 1-3
1- 2 7A42 dimensiona drawing ..................................................................... 1-23
2- 1 Simpified b ock diagram of the 7A42 ...................................................... 2-2
2-2 Definition of the Booean AND, OR, NOT and XOR (EXCLUSIVE-OR)
ogic functions ............................................................................................. 2-3
2-3 Examp es of products of Channe 1 through 4 ....................................... 2-5
2-4 Function /and g OR'ed together ............................................................... 2-6
2-5 Examp e of EDGE Quaified TRIGGER FUNCTION .............................. 2-7
2-6 Exampe of A THEN B Nested Triggering ................................................ 2-8
2-7 7A42 contros, connectors, and indicators .......................................... 2-10
2-8 Se f-test in progress ................................................................................ 2-48
2-9 Se f-test finished ...................................................................................... 2-48
2-10 7A42 front-pane drawing showing pushbuttons and indicators
that are i uminated during the se f-test sequence ............................. 2-49
2-11 Typica sef-test faiure dispay .............................................................. 2-50
2-12 7A42 front-pane contro ights when initiaized ................................. 2-54
2-13 Channe readout dispay ......................................................................... 2-58
2-14 Channe readout disp ay with 10X probes attached to inputs
of CH1, CH2, CH3, and CH4 ................................................................. 2-58
2-15 Timing diagram showing the reationship of the TRIGGER OUT
waveform to the input signas ............................................................... 2-63
2-16 Timing diagram depicting the TRIGGER OUT waveform, as a
resut of the TRIGGER FUNCTION reacting to the input signa s ... 2-63
2- 17 Examp e of A THEN B, eve and EDGE sensitive TRIGGER FUNCTION,
showing the Norma and A THEN B Gate waveform aternatives ... 2-64
3- 1 Triggering on the decima “ 10" event ........................................................3-2
3-2 Dispay of four channes with TRIG VIEW trace ......................................3-3
3-3 Four channe disp ay with an externa c ock signa dispayed on the
TRIG VIEW trace .........................................................................................3-3
3-4 Triggering on a ow-ampitude puse ........................................................3-5
3-5 Timing diagram of a typica microprocessor read cyc e ....................... 3-6
3-6 Set up to monitor invaid data transitions .................................................3-8
3-7 The 7A42 captures a positive transition of data during the time data >
shou d be stab e .........................................................................................3-8
3-8 Bus contention measurement set up .................................................. 3-10 -
3-9 Standard 500-ohm probe forms vo tage divider with termination
resistor ..................................................................................................... 3-14
3-10 Simpified diagram of the P6230 Variabe Bias/Offset probe ........... 3-15 ;
3-11 Two ECL eve waveforms, A without bias offset, B with a -2 vot
bias offset ............................................................................................... 3-16
iv

7A42 Operators
LIST OF TABLES
Table
No. Page
1-1 Shipping Carton Test Strength ................................................................... 1-5
1-2 E ectrica Characteristics ............................................................................ 1-6
1-3 Environmenta Characteristics .............................................................. 1-21
1- 4 Physica Characteristics ......................................................................... 1-22
2- 1 7A42 Sef-Test Fai ure Messages ........................................................... 2-51
2-2 7A42 Front-Pane Contro Settings When Initiaized .......................... 2-53
2-3 7A42 Operator Message Summary ....................................................... 2-55
2-4 Channe Vots/Division Ranges ............................................................ 2-65

7A42 Operators
OPE ATO S SAFETY SUMMA Y
The genera safety information in this part of the summary is for both operating
and sevicing personne . Specific warnings and cautions wi be found throughout
the manua where they appy, but may not appear in this summary.
TE MS
IN THIS MANUAL
CAUTION statements identify conditions or practices that coud resut in damage
to the equipment or other property.
WARNING statements identify conditions or practices that coud resu t in persona
injury or oss of ife.
AS MA KED ON EQUIPMENT
CAUTION indicates a persona injury hazard not immediatey accessibe as one
reads the marking, or a hazard to property incuding the equipment itsef.
DANGER indicates a persona injury hazard immediatey accessibe as one reads
the marking.
SYMBOLS
IN THIS MANUAL
Static-Sensitive Devices
This symbo indicates where app icabe cautionary or other information
is to be found.
AS MA KED ON EQUIPMENT
DANGER — High votage.
Protective ground (earth) termina.
ATTENTION — refer to manua.

7A42 Operators
WA NINGS
POWE SOU CE
This product is intended to operate in a mainframe connected to a power source
that wi not appy more than 250 vots rms between the supp y conductors or
between either supp y conductor and ground. A protective ground connection by
way of the grounding conductor in the mainframe power cord is essentia for safe
operation.
G OUNDING THE P ODUCT
This product is grounded through the grounding connector of the mainframe
power cord. To avoid e ectrica shock, p ug the mainframe power cord into a
proper y wired receptac e before connecting to the product input or output
terminas. A protective-ground connection by way of the grounding conductor in
the mainframe power cord is essentia for safe operation.
DANGE A ISING F OM LOSS OF G OUND
Upon oss of the protective-ground connection, a accessibe conductive parts
(inc uding knobs and contros that may appear to be insuating), can render an
e ectrica shock.
DO NOT OPE ATE IN EXPLOSIVE ATMOSPHE ES
To avoid exp osion, do not operate this product in an atmosphere of exposive
gasses.
DO NOT OPE ATE PLUG-IN UNIT WITHOUT COVE S
To avoid persona injury, do not operate this product without covers or panes
insta ed. Do not appy power to the p ug-in via a pug-in extender.
vii

7M2 Operators
DESC IPTION
The 7A42 Logic Triggered Vertica Ampifier is a four channe, wide bandwidth,
p ug-in unit, compatibe with Tektronix 7000-series Osci oscopes. It was
specifica y designed to dispay and make measurements on digita ogic signas in
the TTL, ECL and CMOS ogic famiies. Whi e the dispay output from the 7A42 is
ana og, the trigger output is digita and is comprised of a user se ectab e Booean
function of the four input channes. A fifth TRIGGER VIEW trace depicts either the
trigger function output or the externa c ock input.
viii

SECTION ONE
GENERAL INFORMATION
Shown above is the Tektronix 7A42, 7A13, and 7B92A
insta ed in a Tektronix 7904A Osci oscope.
The 7904A is a genera purpose, rea -time 7000-series
mainframe, featuring a 300 MHz system bandwidth with
the 7A42.