Fluke 93, 95, 96 Service Manual

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Page 1

FLUKE AND PHILIPS THE GLOBAL ALLIANCE IN TEST & MEASUREMENT

Fluke 93/95/97

Philips PM93/95/97

SCOPEMETER

Service Manual

Ruker 915970

Philipe: 4622 872 05349

920121

Warning: These servicing instructions are for

use

by qualified personnel

oniy. To reduce the risk

of eiecthc shocks do not perform any servicing other

than that specified in the operating

instructions uniess

you are fully qualified to do so.

FLUKE

Page 2

IMPORTANT

correspondence concerning thie

instrument please give the model

number and serial number

as located on

the

type number plate on Ihe Instrument

All moditicallons up

to production data

january 1992

are Incorpe rated In this

manual.

For your reference:

Model number: PMxx

Fluke

Code number : 9444

yyy yyyyy

9444

yyy yyyyy

Serial

number: DM nn

mmmm DM nn

mmmm

Note: The

design of this instrument

is subject to continuous development

and improvement. Consequently,

this instrument may incorporate

minor changes In detail from

the infom}ation contained

in this manual.

No part of this publication may be reproduced by any means

or In any form without written

permission of the copyright owner.

Printed in

The r^eiheriande

Page 3

CONJTENTS

TABLE

CONTENTS Page

1. SAFETY INSTRUCTIONS

1-1

1.1 INTRODUCTION M

1.2 SAFETY PRECAUTIONS

1-1

1.3 CAUTION AND WARNING STATEMENfTS

1-1

1.4 SYMBOLS

1-1

1.5 IMPAIRED SAFETY M

1.6 GENERAL SAFETY INFORMATION M

2. CHARACTERISTICS

2-1

2.A PERFORMANCE CHARACTERISTICS

2-1

2.B SAFETY CHARACTERISTICS

2-1

2.1 DISPLAY

2-1

2.2 SIGNAL ACQUISITION

2-1

2.3 CHANNELS A&B

2-2

2.4 TIMEBASE

2-4

2.5 TRIGGER

2-5

2.6 SIGNAL MEMORY (MODELS 95 AND 97 ONLY)

2-6

2.7 TRACE DISPLAY

2-6

2-8 SETUP MEMORY (MODEL 95 ONLY)

2-6

2.9

SETUP

MEMORY (MODEL 97 ONLY)

2-7

2.10 CALCULATION FACILITIES (MODEL 95 ONLY)

2-8

2.11 CALCULATION

FACILITIES

(MODEL 97 ONLY)

2-8

2.12 CURSORS (MODELS 95 AND 97 ONLY)

2-9

2.13 MULTIMETER

2-9

2.14 AUTO SETTING 2-14

2.15 GENERATOR (MODEL 93 AND

95)

2-16

2.16 GENERATOR (MODEL 97 ONLY)

2-16

Page 4

CONTENTS

2.17

POWER

ADAPTOR BATTERY

CHARGER

2-17

2.18 POWER

SUPPLY

2-17

2.19 MECHANICAL

2-18

2.20 ENVIRONMENTAL

2-19

2.21 INTERFACE (MODEL

97 ONLY)

2-21

2.22

SAFETY

2-22

2.23

ACCESSORIES

2-23

2.24 SERVICE AND MAINTENANCE

2-23

CIRCUIT DISCRIPTIONS

3-1

3-1 INTRODUCTION TO

CIRCUIT DiSCRIPTION 3-1

3.1.1 GENERAL

3-1

3.1.2 LOCATION OF

ELECTRICAL PARTS 3-1

3.2 FUNCTIONAL

BLOCK DISCRIPTION

3-2

3.2.1 INTRODUCTION

3-2

3.2.2

DATA ACQUISITION 3-4

3.3.3 MICROPROCESSOR

3-7

3.3.4 DIGITAL

ASIC (D-ASIC) CIRCUITRY 3-9

3.3.5 LCD CIRCUl'mY

3-12

3.4

ANALOG CIRCUITS (A2)

3-14

3.4.1 INTRODUCTION

3-14

3.4.2 OVERVIEW ANALOG

CIRCUITS 3-14

3.4.3 ATTENUATOR

SECTIONS, CHANNELA

AND

B 3-14

3.4.4 EXTERNAL

(BANANA) INPUT/OUTPOT

CIRCUITRY 3-18

3.4.5 ANALOG

ASIC (A-ASIC) AND ADC CIRCUITRY

3-20

3.4.6 ANALOG CONTROL

CIRCUIT 3-24

3.4.7 GENERATOR

CIRCUIT 3-30

3.4.8

BATTERY CHARGER

3-32

3.4.9 POWER SUPPLY

3-34

PERFORMANCE VERFICATION

PROCEDURE

4-1

4.1 GENERAL

INFORMATION 4-1

4.2 STANDARD PERFORMANCE

VERFICATION PROCEDURE 4-2

4.3 STANDARD

PERFORMANCE VERFICATION PROCEDURE

SUMMARY

4-16

4.4 AODmONAL PERFORMANCE

VERFICATION PROCEDURE 4-17

Page 5

CONTENTS

CALIBRATION

ADJUSTMENT

PROCEDURE 5-1

5.1 GENERAL INFORMATION

5-1

5.2 RECOMMENDED

CALIBRATION ADJUSTMENT

EQUIPMENT 5-1

5.3 ENTERING

THE CALIBRATION PROCEDURE

5-2

5.4 OPERATING THE

CAUBRATION PROCEDURE

5-3

5.5

CONTRAST CALIBRATION

ADJUSTMENT PROCEDURE 5-4

5.6

SCOPE CALIBRATION ADJUSTMENT

PROCEDURE 5-4

5.6.1 HARDWARE

SCOPE CAUBRATION

ADJUSTMENTS

5-4

5.6.2 CLOSED

CASE SCOPE CALIBRATION

ADJUSTMENTS 5-8

5.7 METER CAUBRATION

ADJUSTMENT

PROCEDURE

5-15

5.8

CALIBRATION ADJUSTMENT

PROCEDURE

SUMMARY 5-24

DISASSEMBLING THE

SCOPEMETER

6-1

6.1

GENERAL INFORMATION

6-1

6.2. DISASSEMBLY

PROCEDURE

6-1

6.2.1 REMOVING

THE BATTERY

PACK

6-2

6.2.2 OPENING

THE SCOPEMETER

6-2

6.2.3

REMOVING

THE ANALOG A2 PCB. TO ENABLE

HARDWARE

SCOPE CAUBRATION

ADJUSTMENTS 6-4

6.2.4

REMOVING THE

DIGITAL A1 PCB 6-4

CORRECTIVE MAINTENANCE

7-1

7,1 DIAGNOSTIC

TESTING AND TROUBLESHOOTING

7-1

7.1.1 INTRODUCTION

7-1

7.1.2 TROUBLESHOOTING

TECHNIQUES

7-1

7.1.3 DISPLAY AND

ERROR MESSAGES

7-2

7.1.4 MAIN TESTS

7-5

7.1.5 TROUBLESHOOTING

7-7

7.1.6 DIGITAL

At PCB TROUBLESHOOTING

7-7

7.1.7 ANALOG

A2 PCB TROUBLESHOOTING

7-28

72 REPLACEMB^TS

7-40

7.2.1 STANDARD

PARTS

7-40

7.2.2 SPECIAL PARTS

7-40

7.2.3 TRANSISTORS

AND INTEGRATED CIRCUITS

7-40

7.2.4

STATIC-SENSITIVE

COMPONENTS

7-40

7.2.5

REPLACEMENT

OF PARTS

7-42

7.3

SOLDERING TECHNIQUES

7.5I

7-3-1 GENERAL

SOLDERING TECHNIQUES

7-51

7.3.2 SOLDERING

MICRO-MINIATURE

SEMICONDUCTORS 7-51

Page 6

CONTENTS

SPECIAL TOOLS 7-52

7.4.1

EXTENDER FLAT CABLE 7-52

7.5

RECALIBRATION AFTER REPAIR 7-52

7.6

INSTRUMENT REPACKING 7-52

MAINTENANCE OF THE PRIMARY

CIRCUIT (PM8907/...)

8-1

9. REPLACEABLE PARTS LIST 9-1

9.1 INTRODUCTION 9-1

9.2 HOW TO

OBTAIN PARTS

9-2

10. CIRCUIT DIAGRAMS 10-1

Page 7

-2

SAFETY INSTRUCTIONS

1.5 IMPAIRED SAFETY

Whenever

H Is

likely

that safety has been Impaired, the Instrument must be turned off and

disconnected

from all external voltage sources, and the batteries must be removed. The matter

should then be referred to qualified technicians. Safety Is likely to be impaired if, for example,

the

instrument fails to perform the intended measurements or shows visible damage.

1 .6 GENERAL SAFETY INFORMATION

WARNING: Removing the instrument covers or removing parts,

except those to which

access can be gained by hand, is likely to expose live parts and

accessible

terminals which can be dang^ous to life.

The instrument must be disconnected frorr> all voltage sources and batteries must

removed before

rt is opened.

Capacitors inside the instrument can hold their charge even if

the

instrument

has been separated

from all voltage sources and batteries are removed. Components which are important

for

the safety

of the Instrument may only be replaced by components obtained through your local FLUKE/PH I LI PS

organization. These components are Indcated by an asterisk

(*)

In the parts list sechon (chapters).

Page 8

CHARACTERISTICS

2-1

CHARACTERISTICS

A. Performance

Characteristics

PHILIPS and FLUKE guarantee the properties

expressed in numerical values with stated

tolerance. Specified non-tolerance numerical values

indicate those that coutd be nomir^lly

expected

from the mean of a range of identical instruments.

•

For definitions

of terms, reference is made to lEC Publicatjon 351-1

•

The accuracy of all measurements

Is within i: {(Si of reading) ±(one least-significant

digit)}

from 18C to

28C.

Add 0.1 X (specified accuracy

)/C for

16C or

28C

ambient.

B. Safety Characteristics

The Instrument has

been designed and tested in accordance with

I EC Publication 348, Safety

Requirements for Electronic

Measuring Apparatus, and has

been

supplied

in a safe condition. This

manual contains Information

and

warnings

that must be followed by the user to ensure safe

operation

and to keep the instrument in

safe

condition.

2.1 DISPLAY

CHARACTERISTICS

SPECIRCATtONS ADDITIONAL

INFORMATION

Type

LCD

Useful Screen Area

64 mm x 64 mm 1 div equals

pixels.

1 div equals 8.75

mm.

Resolution

240 x 240 pixels

•

Contrast Ratio

Adjustable via LCD

Menu.

•

Backlight (Model

only)

Electro Luminescence

2.2 SIGNAL ACQUISITION

•

Sampling

Type

@ 1 ps/div...60s/dlv

@10 ns/div...500 ns/di

Real Time

Quasi Random

•

Maximum Sample Rate 25 MS/s

Sampling Rate depends on tims/div

setting.

Maximum Vertical

(voltage) Resolution

6 bits Over 10

divisions.

Maximum Horizontal

(time)

Resolution

25 Samples/div Per Channel-

Record Length

With capture

20 div 512 Samples

Per Channel.

With capture

1 0 div 256 Samples Per

Channel.

Page 9

2-2

CHARACTERiSTiCS

CHARACTERISTICS

SPECIFICATIONS

Acquisition Time

(for 20.4 dlv)

60s/dlv...1 ys/Olv

500 ns/div...10

ns/div

Sources

•

Acquisition Modes

20-5 X tlme/div

-i-

140 ms

20.5 X time/div + 120 ms

Channel A Channel

mV Input

1 Channel Only

2 Channels

ADDITIONAL INFORMATION

Excluding delay

time.

Delay time

Is the selected trigger

delay.

Excluding delay time.

In Quasi-Random Mode,

the

acquisition time depends

triggers.

CHAN A, CHAN B

Chopped Mods from

60sydiv...50 ps/div.

Alternating Mode from

ps/drv...10 ns/div.

2.3 CHANNELS A

& B

Signal Inputs Isolated BNC Signal

Input BNC commons are

connected together.

Common Input

•

Input Impedance

R parallel

Black Safety Banana Jack

1 MO± 1%

Part of External

Trigger Input.

Frequency dependent, see

Figure 2.1.

For DC coupled input. For AC coupled input or GND, add 22

nF in

series with R

and C parallel.

parallel

MAX. INPUT

IMPEDANCE

Figure 2. 1 Max. Iriput

Impedance Versus Frequency

rvn

Page 10

CHARACTERISTICS

•

CHARACTERISTICS

SPECIFICATIONS

ADDITIONAL

INFORMATION

•

Input Coupling

AC DC GND

Sequence: ac-doGND

(pre-charge

ac), and back to ac.

•

Maximum Input

Voltage

300

(rms)

MAX. PEAK

VOLTAGE

Figure 2.2

Max Input Voltage

Versus Frequency

•

Defiection

Coefftelent

Frequency dependent

see fig. 2.2

Between BNC

inner and outer

contact. Outer BNC

contacts and

Ground (Black) Banana

Jack are

internally

connected

together.

Steps

1 mV/dlv...2 mV/div

(Models

95 and 97 only)

Steps

5 mV/d(V...100V/div

Error Limit

Overall

Nonlinearity

(

2% ± 1 digit)

(2% 1 1 cfgit)

Dynamic

Range

9.5 div

4 div

Position

Range

(move

control)

4 dlv...+ 4 div

Frequency Response

Lower Transition

Point

of Bandwidth

Only (or repetitive

signals and

llmebase 60

s...1mS-

if one of the

channels is

in this sensitivity, both

channels will be switched to

Average =

1-2-5

sequence ot

positions.

Add 3% tor 1

mV and 2 mV

per (EC 351 for

frequencies

1 MHz.

for frequencies <

10 MHz.

for frequencies

up to 50 MHz.

Z source

500.

DC Input

Coupling

AC Input

Coupling

3dB

1 0 Hz <

1 Hz including

10 MO probe.

Upper Transition

Point

50 MHz (-3 dB)

of Bandwidth

Subtract

MHz for <

18 ®C

and

28 Ambient.

Rise

time 7 ns.

Page 11

2-4

CHARACTERISTICS

CHARACTERISTICS SPECIFICATIONS ADDtTtONAL

INFORMATION

•

Max. Baseline Inetabllity

Jump

0.1

dlvor

1 mV The baseline is automaticalfy

reac|usted after switching the

attenuator or AC/DC/GND.

•

Average

(Models

and

only)

Running Average.

Maximum Constant 256x

Constant in Roll lOX

•

MIN MAX

(Models 95 and 97 only)

Channel A only.

Tlmebase setting

Pulse-wkJlh for 1X%

Probability

Pulse-wWtti for 25%

Probability

^s/dlv

40 ns

10 ns

ZOOM

(Models 95 and 97 only)

Expansion or compression in

1,2,5

sequence around the 4th division.

Range for Delay <640div

TIMEBASE

•

Modes Recurrent

Single Shot

Roll

Automatic selected.

Ranges

Recurrent 5s/dlv...10 ns/div

Dual Channel Chopped 5a/div...50 pa/di

Dual Channel Alternate 20 pa/d iv... 10 ns/div

Single Shot 5s/dlv...10 ns/dlv Every sweep needs

trigger.

A sweep first; B sweep arms

automatically.

For 500 ns, 200 ns, and 1 00 ns; an

automatic Interpolation lakes place.

Chopped.

Roll

Mode 60s/div...10s/dlv

Maximum Timabase Error ± 0.1 % ± 1 LSB

Page 12

CHARACTERISTICS

2-5

CHARACTERISTICS SPECIFICATIONS ADDITIONAL INFORMATION

2.5 TRIGGER

•

Sources

Sheeted

Independently.

Channel

Signal

Channel B Signal

External Trigger Input

GHANA

CHAN B

EXT

External Trigger Input

Connector

Dual Salety Banana Jack External Trigger Input common

(low) jack is electrically

connected to the Channel A and Channel B commons (outer

contact of BNC's).

External Tiigger Input

Impedance

parallel

1 MJ^±1% If used for mV DC>1 MQ.

C parallel

pF Including Banana to BNC adapter.

•

Trigger Error For frequencies < 1 MHz.

Voltage Level ±1 LSB

±0.5 div

5s;dlv...50MS/dlv.

|i8/div...10 ns/div.

Time Delay ±1 LSB

±5 ns

•

Maximum External Trigger

Input (rms)

300 V Frequency dependent, see fig. 2.2.

•

Trigger Sensitivity For

Models 95 and

97,

values must

be multiplied by 5 In 2 mV/dIv. and

1 mn/dfv.

Charrnel A or B

a 100 MHz ^ 60

MHz

@ 10 MHz

54 div

51.5 div

50.5 div

External Trigger input TTL logic compatible using

10;1

attenuation

Probe.

•

Trigger Slope Selection positive going

negative going

•

Trigger Level Control

Range

Channel

A or B

Trigger at 50%

External Trigger Input

±4 div

0.5 X peak/t^ak value

Fixed @ TTL:10

Measured during

20 ms.

Switchable

lo TTL via set-up menu.

Page 13

2-6

CHARACTERISTICS

SPECIFICATIONS

ADDITIONAL

INFORMATION

N-cycle

mode

(Models 95 and 97 only)

5s/fliv...1 ^s/dJV, N=

2...255 For

tlmebase settings from

20^s/dfv...1 ps/div acquisition

and

trigger on Channel A only.

Events

(5s/div...1 ys/div) 1...1023 Start via

Ext; count with channel

•

Trigger

Delay

Range •20...

640 div

2.6

SIGNAL MEMORY

(MODELS 95 AND 97

ONLY)

•

Signal Memory

Size

Memoiies 8

Memory *1 up to #8.

Memory Depth

512 words

Wordlength

6 Bit

Functions

Store Storage

of signals.

Save

Contents of Channel A and

Channel B are saved in temp

memory #1 and

#2, and (A ± B) in

temp memory

#3,

2.7 TRACE DISPLAY

•

Sources

Channel

A A Maximum of 4 traces

plus A vs B

Channel B

A±B

A vs B

can be selected.

Memory #1 up to #8 (Models

95 and 97 only).

Position range

Horizontal

+ 4dfv...- 16.5 div

Vertical

•

4 (jlv...+ 4 div

From screen center, select per

trace.

2.8 SETUP

MEMORY (MODEL

95 ONLY)

•

Memory

Size 8 maximum

Combined with waveform.

Page 14

CHARACTERfSTICS

2-7

CHARACTERISTICS

SPECIFICATIONS

2.9

SETUP MEMORY (MODEL

97 ONLY)

•

Memory

Sl2e 10 maximum

•

Functions

Save

Delete

Recall

With soft up/down

keys Next

Initial setup

selection of AUTO SET

only Amplitude

or>ly Time

Time and Amplitude

trace identification

on/off

trigger identification

on/off

trigger

sensitivity external

0.2V/2V

Clear

after Hold^un

on/off

refresh time

% RECORD

in scope mode

infinite

2 seconds 5

seconds

1 0 seconds

60 seconds

ADDITIONAL INFORMATION

Front Panel

setups.

Actual front

panel settings are

stored In memory*

replacing

contents of memory

location

Indicated on LCD.

Contenis of memory tocation

indicated on LCD are deleted.

Actual front panel

settings are

replaced

contents

of memory

location indicated

on LCD.

Actual settings are replaced

contents of the next

(+1

)

memory

location

Indicated on LCD.

Actual settings are replaced

contents of the previous

(-1)

memory location indicated

on LCD.

Page 15

2 -S

CHARACTERISTICS

CHARACTERISTICS SPECIFICATIONS ADDITIONAL INFORMATION

2.1 0 CALCULATION FACILITIES (MODEL

ONLY)

•

Measurement Functions

della V

della

RMS value

Mean (Average) value

Peak to Peak value

Rise or Fall lime

Frequency

1 delta t

Maximum value

Minimum value

Phase

Trigger time to cursor

Ratio

Maximum of

6imultar>90us

measurement functions.

V of portion between portion.

£xpresslor> of value in % or

absolute on any one of the above

values.

2.11 CALCULATION FACILITIES (MODEL

ONLY]

* Measurement

Functions Maxmum of 5 simultaneous

measurement functions.

delta V

delta t

RMS value

Mean (Average) value

Peak to Peak value

Rise or Fall time

Frequency

1 delta

Maximum value

Minimum value

Phase

Trigger time to cursor

Ratio

> of portion between portion.

Expression of value In % or

absolute on any one of the above

values.

•

Mathematics Multiplication

Add

Subtract

Fitter

Invert

Integrate

of whole memory or Channel.

For timebase settings

...10 ns, only displayed

Channels can be used.

Page 16

CHARACTERISTICS

-g

CHARACTERISTICS

SPECIFICATIONS

2.12

CURSORS (MODELS

95 AND

97 ONLY)

Horizontal

Display Resolution

Digital

Readout Resolution

Error Limit

Cursor

Range

Vertical

Display Resolution

Digital Readout Resolution

Error Limit

parts

per div

3 digits

±0.1%±1

LSB

Visible

part of signal

25 parts per dIv

3 digits

±2%

ADDITIONAL INFORMATION

Cursors

cannot pass each

other.

Referred to Input

at BNC or Probe

tip, after Probe recalibration.

2.13 MULTIMETER

The Multimeter

uses the Channel A input

for VDC & VAC measuremenlsand

the

Safety Banana Jack

Inputs for Resistance,

Diode Test,

Continuity, and DC mV measurements.

An Internal

reference is

used to optimize the

accuracy of the Channel

A Input and any

probes used. The accuracy

all

Multimeter

measurements

Is within

± {(%

of reading)

(number of least-significant

digits)) from

18 *C

to 28

®C

with relative

humidity up to 20% fora period

of one year after calibration.

Add 0.1 x

{specified

accuracy)/C

for 18 or 28

”C Ambient.

•

Displayed

range include used

probe, if calibrated.

•

Values listed

are without

attenuating probe.

•

A Vrms

AC and V DC

dual display mode Is optimized

for power line

(mains) related

measurements.

•

Voltage

Ranges

300 mV. 3V. 30V

& 300V Manual

or automatic ranging

peak voltage.

High Voltage x10

Probe extends

measurement

600V. Peak

voltage is 2.5x range,

except

375V In 300V range.

Resolution

0.1 mV, 1 mV,

0.01V,

&0.1V

Multiply

x10 with High Voltage

Probe-

Accuracy

(0.5% +

Digital

Display

3000

counts

Up to 4500 counts,

3500 counts in

300V range.

Display update

Response

Time

300 ms

<3.5s

Zeroing

automatic

Series Mode

Rejection

Ratio

> 50

dB @ 50 Kz

or 60 Hz

Page 17

CHARACTERISTICS

CHARACTERISTICS SPECIFICATIONS

ADDITIONAL INFORMATION

•

AC Voltage

Ranges

300 mV. 3V, 30V, 250V Manual or automatic ranging

peak voltage.

High Voltage xIO Probe

extends

measurement to 600V. Peak

voltage is 2.5x range and 375V in

250V range.

Resolution 0.1 mV, 1 mV, 0.01 V.

0.1V Multiply X10 with High Voltage

Probe.

Accuracy (AC Coupled)

Using High Voltage 10:1

Probe

Valid from 5%.. 100% of range.

50 Hz... 60 Hz

±(1%+ 10)

20 Hz... 20 kHz ±(2%+

15)

5HZ...1 MHz

Accuracy (DC Coupled)

Using High Voltage 10:1

Probe

(3% +

20)

50 Hz... 60 Hz

(1% +

10)

1 Hz.. .20 kHz

(2% +

15)

Crest Factor

Meter prevents crest factor errors by autoranging on Input waveform

peaks.

Digital Display

3000 counts Up to 4500 counts,

at 260V range: 2500.

Display Update c 300 ms

Response Time

@ Input freq

>50

3.5s

SMOOTH < 10s

FAST < Is

DC Common Mods

Rejection Ratio

> 100 dB

@ dc

100 dB @

50, 60.

or 400 Hz

AC Common

Mode

Rejection

Ratio >60d6 @ dc..60Hz

Page 18

CHARACTERISTICS

2-11

CHARACTERISTICS

SPECIFICATIONS

ADDHIONAL INFORMATION

« Resistance

Open Circuit

Voltage < 4V

Full

Scale Voltage

300n...3 Mfi <

250 mV

<2V

Ranges

300Q, 3 kii, 30 kil

300 kD. 3

30 MLl

Manual or

automatic ranging.

Resolution

0.10.0.001 kil 0.01 kO.

0.1 kO, 0.001

Mn, 0.01 MO

Accuracy

(0.5% +

Digital

Display

3000 counts

Up to 4500

counts, at 30 MO 3000

Measurement

Current

0.5 mA...70 nA

Decreases

as range increases.

Display Update <

300 ms

Response

Time <3.5$

SMOOTH

<10s

FAST <

Protection

600V RMS

Continuity

Beeps

if resistance is <:

•

Diode Test

Maximum

Voltage

Range

Resolution

Accuracy

Digital

DiS(^ay

Measurement Current

Display update

Response Time

SMOOTH

FAST

Protection

Polarity

Continuity (Alert)

5% of selected

Is indicated if measured voltage

2.8V.

2.800V

0.001V

±{2%

3000 counts

If value >

2800 readout gives

OL.

0.5 mA

<300

3.5s

<10s

<1s

600 V RMS

on RED

Banana Jack

on BLACK

Banana Jack

Beeps if reading

is below 1

Page 19

•

12 CHARACTERISTICS

CHARACTERISTICS SPECIFICATIONS ADDITIONAL INFORMATION

•

DC mV Banana Jack Inputs Used for Accessory (lr>cludlng

Temperature) input.

Ranges

300

3V Manual or Automatic

ranging.

Resolution 0.1 mV

1 mV

Accuracy

(0.5%

Digital

Display 3000 Counts Up to 3500 Counts.

Display update

<300

Response Time

SMOOTH

FAST

< 3.5s

<10s

Input

•K

on RED Banana Jack

on BLACK Banana Jack

•

Multimeter Math (Display)

Functions (Models

95 and

97 only)

Relative ZERO delta Displayed

Value

Reading

Reference Reading.

% Change

Relative) ZERO % delta Displayed Value

{(Reading/Refe

rence Reading) -1} x 100.

% Scale Displayed Value

{(Reading-Set

0% Reading)/{Set 1(X)% Reading-

Set 0% Reading)} x 100%.

SetO^ Reference SetO% Present, Maximum. Minimum,

Average.

Set 100% Reference Set 100% Present. Maximum, Minimum,

Average.

Power with respect to

1 mW in selected load

resistance

dBm

Select load resistance 1200, 1000, 900, 800, 600,

500, 300, 250, 150, 135, 125, 110, 93,75, 60&50

Voltage Ratio in dS with

respect to tV

dBV

Audio power WATTS or dBW

Select load resistance 50,16,

8, 4.

2 & in

Page 20

CHARACTERISTICS

2-13

CHARACTERISTICS

SPECIFICATIONS ADDITIONAL

INFORMATION

•

Other Multimeter

Operating Modes

Touch Hold HOLD

Causes the meter to

capture the

ne)(t measured reading

(and beep)

when a new stable measurement

has been detected.

When first

enabled, the numeric display is

frozen (held) until a stable

measurement is detected. Stable

measurements are defined as

with

in ± 100 display counts for 4

measurements ("Is.); and above

floor of 200 display counts m volts

(300 counts in ac, below 4000

counts in O ar>d below 2800 counts

in diode). Overload Is a valid stable

condition except In £2 and diode

test.

MIN MAX recording

(Models 95 and 97

only) RECORD

Simultaneous displays o1

Maximum. Minimum. Peakto Peak.

Average* arvJ Present reading.

•

Frequency

Range

1 H2...5 MHz Manual for

frequencies < 20 Hz.

Accuracy +/-

(0.5% + 2 counts)

Tlmebd&e

Accuracy +/-0.01%

Resolution 4

digits

Measuring Time

3.5s gradually

degradation from 100 Hz

SMOOTH

<10s and down.

FAST < 1

s Running average

over 32

measurements.

Ranging

Automatic

•

AUTO RANGE

Vdtage

and Time are coupled.

Voltage Range_Up

3500 Maximum

reading in manual range

@ 300

mV,

3V> 30V : 4500.

Voltage

Range.Down 0300

@external Input:

3500.

Time Range_Up

5 ms.

..50

periods fn display

TIME switch selects manual

timebase.

US...1 us

periods

in display AUTOSET

starts timebase ranging.

Ttme Range.Down

5 ms.

..50 )is <1.5 periods in display

US...1

0.75 periods in display

Page 21

•

CHARACTERISTICS

SPECIFICATIONS

ADDITIONAL INFORMATION

2.14

AUTO SETTING

•

Settling

time 3s

The default values

are indicated

(Model 97 only).

If this can be

changed with the

aid

the SETUP

(auto-set) menu, tnis is

shown.

Selectable

mode of

opefatl<xi

(Model 97 only) Selected

in^al

setup.

Complete

•

Display functions

Channel Baseline

mid screen

One channel display.

Separate

+ 1 div 1

a -

1 dlv

Dug^ Channel display.

X-position

zero

SETUP: not affected

(Model 97 only).

Y-posil[ion zero

SETUP:

not

affected

or separation

(Model 97

only).

X-expand

X 1

A vs B off

SETUP: not affected

(Model

97 only).

•

Cursors

not affected

cursors

are on a not the selected

channel, Channel A. SETUP: not

affected (Model 97 only).

Mathematics off

SETUP: not affected

{Model 97 only).

•

Text Not affected Except for actual

setting, that is

adapted (Model 97 only).

Trace identification

on SETUP:

OFF (Model

only).

•

Vertical

AcQuisition

Y deflection source Every

source having a

thggerable signal at its Input

Channel

A if no trigger is found.

Input coupling

ac SETUP: not

affected

(Model 97 only).

Y deflection

Each channel is independently set.

Input

voltage

> 20 mV approx.

dIv

Input voltage < 20

mV Channel at 200 mV/dIv Due to trigger

uncertainty at freq.

> 2 MHz Of

at duty cycle

50%

sensitivity can deviate from

above,

but signal will remain on the screen.

Page 22

CHARACTERISTICS

2-15

CHARACTERISTICS

Average

•

Horizontal

Acquisition

TB Deflection

coefficient

Signal 40 Hz..

MHz

Signal

5 MH2...50

MHz

When no trigger found

•

Triggering

Delay

a 0

Negative

delay

Triggerable signal

@ ext. input

No signal

@ ext input

but trig, signal

@ channel

A or 8

No triggerable

signal.

@ any

input

Level

Slope

Events

(Models

95 and 97 only)

N-Cycle (Models 95

and 97 only)

•

Nferious

Generator (Model

97 only)

Record restart

timing

(Model

97 only)

SPECIFICATIONS

ADDITIONAL

INFORMATION

off

SET-UP: not affected

(Model 97 only).

Free Run

Recurrent

min.

max 6 signal

periods

over

ddiv

min.

max 20 signal

periods

over 8 div

5 ms/div

Off

SETUP:

not affected

(Model

97 only).

Not

affected

SETUP:selectAorB

(Model

97 only).

channel

channel B

Channel

with lowest Input

frequency

Is selected (Channel

when frequencies

are equal).

Channel

40...

60% of p©ak-tQ-peak

After

Autoset.

value

SETUP:

not affected

(Model 97

only).

Pos

itive

SETUP : not affected

(Model 97

only).

OFF

SET-UP; not affected

(Model

97 only).

OFF

SET-UP;

not affected

(Model 97

only).

OFF

SETUP: not

affected.

OFF

SETUP:

2,5.10 or

60s

acquisitions,

whichever 1

$ the

shortest.

Page 23

2-16

CHARACTERISTICS

CHARACTERISTICS SPECIFICATIONS

ADDITIONAL INFORMATION

2.15 GENERATOR (MODEL

AND

95)

Probe Adjust A square wave voltage is available

via the external trigger input for

adjusting probe compensation.

Voltage

(p-p)

Frequency 976 Hz

Source resistance 400ii

DC Calibration Including 10:1 attenuatior> Probe.

Voltage

3V Inaccuracy is

optimized

internally.

Source resistance 4000

2.16 GENERATOR (MODEL

ONLY)

Probe Adjust A square wave voltage Is available

via the external trigger input tor

adjusting probe compensatbn.

Voltage

(p-p)

Frequency 976 Hz

Source

resistance 4000

•

DC Calibration Including 10:1 attenuation Probe.

Voltage

(p-p)

3V Inaccuracy is optimized internally.

Source resistance 4000

LF Sine wave

Amplitude

(p-p)

Frequency 976 Hz

Max. Individual Harmonic 3%

Source

resistance 4000

•

Square wave

Amplitude

(p-p)

Frequency 1.95 kHz

978 Hz 488 Hz

selectable

Source Resistance 4000

Page 24

CHARACTERISTICS

2-17

2.17

2.18

CHARACTERISTICS SPECIFICATIONS

ADDITIONAL INFORMATION

•

DAC Output Current

Can

be used for a component

Amplitude

0 mA...+ 3mA

tester.

In max. 126

amplitude st^. The

Max. voltage

time

for

every step can differ.

DAC output voltage

In max. 126 amplihjde

steps. The

Amplitude

-2V...+

time for every step

can

differ.

Max. Current

± 1 mA

POWER ADAPTOR /BATTERY CHARGER

Input Connector

5 mm Power Jack

Per DIN 45323

Source Voltage

Nominal 15V dc

Limits

of Operation 8V...20V dc

•

Charging Current

Instrument ON

60 mA

Instrument OFF

170 mA

•

Allowable Temperature

During Charging

0®C...46 “C

•

Power Consumption

Instrument ON 5W

Instrument

OFF 3W

POWER

SUPPLY

•

Battery

Voltage Range 4V...6V

The batteries are not charged

delivery. A warning is given if the

battery voltage becomes lower than

4.4V, "Hie instrument is switched off

if the

battery voltage becomes

lower

than 4 V.

If the instrument Is Battery

Powered,

it will switch off

automatrcaJly after 10 minutes of

operator

actions, except in

RECORD

or ROLL mode.

Page 25

•

CHARACTERISTICS

CHARACTERISTICS SPECIFICATIONS

ADDITIONAL

INFORMATION

•

Recommended

Batteries

NICad

Battery Pack PM 9086/001

Recharging

time 16 hours

Life time

Operating time >

4 hours

Stand Alone Batteries

(4x)

Model

KR27/S0

K70

C-CELL

Operating time > 4

hours

Temperature Rise of 20

Batteries

Temperature Range of

Alkaline Batteries.

Working

-20...65*C

Storage

-30...65“C

Only this Battery Pack Is internally

re-chargeable.

After

500 cycles the capacity will be

>1100

mAh- The nominal capacity

is 2200 mAh.

After

Charging for

15 hours.

perlEC.

per ANSI

After instrument has reached a

stable operating

temperature.

)t is recommended to remove the

batteries from the

instrument when

it is stored longer than 24 hours

below

30 ®C or above

60 ®C.

CAIiTIONI UNDER NO

CIRCUMSTANCES

SHOULD

BATTERIES

BE LEFT IN THE

INSTRUMENT

TEMPERATURES

BEYOND THE

RATED SPECiFICATlONS

OFTHE

BATTERIES BEING USEDI

2.19

MECHANICAL

Height 262

mm With holster 281

mm.

Width

129 mm

With holster 140 mm.

Depth

60 mm With

holster 62 mm.

Weight 1.5 kg With holster

ca 1-8 kg.

Page 26

CHARACTERISTICS

SPECIFICATIONS

ADDITIONAL INFORMATION

2.20 ENVIRONMENTAL

The

characteristics

are valid only If the instrument is

checked in accordance with the official checking

procedure.

•

Meets Environmental MIL-T-2a800D

Type 111

Requirements

of: Class

Style

•

Temperature

Batteries

removed from Instrument

Operating

0 “C...50

unless

Pdttenes meet the required

tmperature

specifications.

Maximum

Operating Temperature

derated

for

each km. (each

3000 feet) above sea level.

Non Operating (Storage)

•

20 ^..70 “C

Maximum Humidity

Non Operating (Storage)

95% Relative Humidity

Operating

20^C...30 90%

30 ®C...50“C

70%

•

Maximum Altitude

Memory backup batteries removed

Operating

km(10

OOOfeet)

from instrument unless batteries

meet maximum altitude

specifications.

Non Operating (Storage) 12

km (40 000 feet)

•

Vlpraoon

(Operating)

Frequency

5w.15 Hz Sweep Time 7 min.

Excursion

(pk to pk) 1.5 mm

Max Acceleration

m/s*

(0.7 X

@ 15 Hz.

Frequency

15... 25 Hz Sweep Time

3 min.

Excursion (pk

to pk)

1.0

Max Acceleration 13

m/s* (1.3 X

@ 25 Hz.

Frequency

25... 55 Hz Sweep Time

min.

Excursion

(pk to pk) 0.5 mm

Max Acceleration

30 m/s* (3.0 X

@ 55 Hz.

Page 27

2-20

CHAftACTEHISTICS

CHARACTERISTICS

Resonance Dwell

•

Shock (Operating)

Number of shocks

Shock Wave Form

Duration

Peak Acceleration

•

Bench Handling

Meets requirements of:

•

Salt Atmosphere

Structural parts meet

•

EMI (Electro Magnetic

Interference)

Meets requirements of:

Packing meets

requirements of:

Transportation meets

requirements of:

Packaged Transportation

Drop meets requirements

of:

Packaged Transportation

Vibration meets

requirements of:

•

ESD (Electrostatic

Discharge) meets

requirements of:

SPECIFICATIONS ADDITIONAL INFORMATION

10 min. @ each resonance frequency (or

@ 33 Hz If no resonance Is found).

18 Total

6 Each Axis

in each direction).

Half Sine

6...

400 m/s*

(40 xg)

MIL-STD-810, Method

516,

Procedure

MIL-STD-810, Method 509,

Procedure I with 5 % salt

solution

MIL-STD-461

Class

Applicable

requirements of Part 7:

CEOS, CE07, CS01, CS02, CS06, RE02, RS03.(RS02: max 2 div

distorsion in 20

mV/div)

VDE 0871

and

VDE 0875

Grenzwertkiasse

UNO 1400

AN-D628

Nat

Safa Transp.

Assoc.

Procedure

A-B-2

Nat. Safe Transp. Assoc.

Procedure 1A-B-1

lEC

801-2

Test severity level 15 kV.

Page 28

CHARACTERISTICS 2-21

CHARACTERISTICS SPECIFICATIONS

ADDITIONAL INFORMATION

2.21 INTERFACE (MODEL 97 ONLY)

•

Type of Interface RS-232-C

Optical.

Plug

pole D’plug male

•

Spacing

Ught

•r

light

Interface function

repertoiry for printers

Baud Rate 1200, 9600 Input and

Output

are

the same

Number of STOP

bits 1

Parity No

Character length

Tranmission

mode Asynchronous, full duplex

Handshake

XON/XOFF Software handshake only.

•

interface function

repertoiry for Interface

Baud

Rate 75...19K2 Input and Output are the same

Selectable by controller.

Number od STOP bits 1

Parity No, Odd or Even

Character length 8

Tranmission mode Asynchronous, full duplex

Handshake

XON/XOFF or no Handshake Software handshake only;

d^ault: no Handshake.

•

facilities

Protocol EPSON FX.

LQ compatible

HP ThinkJet compallbfe

Print out

Screen

log of readings:

single

every

60s

selectable waveform

•

Front Panel Control

Modes Local

Frorrt panel exclusively under

manual control.

Remote-locked

Front panel exclusively under

RS-232-C control.

Remote'UnlocKed Return To Local

by User

ReQuest

Page 29

2-22

CHARACTERISTICS

SPECIFICATIONS

•

CPL Protocol Implemented:

Go to Remote

Go to Local

Local Lockout

Reset Instrument

(Master Reset)

Status Query

IDantifiCdtion

query ID

Auto

Setup AS

Default

Setup

Program

Setup

Query Setup

Recall Setup

Save

Setup

Program

Communication

parameter

Arm Trigger

Trigger

acquisition TA

Query

Waveform QW

Program

Waveform

Query

for Measurement

data

SAFETY

•

Meets

requirements of: lEC

348Clas8 II

VDE0411 Class II

ANSI/ISA SQ2

UL1244

CSA C22.2 No. 231

•

Approvals

VOE 0411 (applied for)

UL 1244 (applied for)

CSA

C22.2 No. 231

(applied

for)

ADDITIONAL

INFORMATION

Restricted;

only

0* 1= 2=

. Gives

Type

number and software version,

Default

Scope settng.

Has

to be done whh the string

that

comes out with QS.

With or without

battery charger.

With or

without battery charger.

Page 30

CHARACTERISTICS

2-23

CHARACTERISTICS

SPECIFICATIONS

2.23 ACCESSORIES

Accessories furnished with

insirument: Users

Manual

Quick Operating Guide

8918/002

ScopeMeter

Accessory set:

adapter

X High voltage

testpin

2 X Earth lead 2 X Trim screwdriver 4

mm adapter

Banana

to 8 NC adapter PM

9061/O0

Set Testleads

and Testpins:

2 X testleads

2 X testpins 2 X banana adapter

Holster

9083/001

Accessory

case C 75

Power Adaptor/Battery

Charger:

PM 8907/001 PM 8907/003 PM 8907/004 PM 8907/008

PM9080/001 (Model

97 Only)

2.24 SERVICE AND

MAINTENANCE

•

Main Time Between

Failures

(MTBF) 40 OOO hours

•

Calibration Interval

year

Mean Time

To Calibrate 30 minutes

(MTTC)

ADDITIONAL INFORMATION

2 X

Mli 10:1

Passive Probe,

1.5m.

shrouded.

Depends on model:

Universal

Europe.

North American.

United Kingdom.

Universal 115V/ 230V.

RS-232-C Interface

Predicted value, calculated

through

parts counting

method, according

toMILHDBK- 217E.

Page 31

CIRCLUT DESCRIPTIONS

3 CIRCUIT DESCRIPTIONS

3.1 INTRODUCTION TO CIRCUIT

DESCRIPTION

3.1.1 General

This chapter prasants a layarad description of the ScopeMeter circuitry. First the

ScopaM

star's

overall theory

operation

Is described, referring to the overall block diagram (section

3.2).

Tho next section gives

some Information conoeming the ScopeMeter’s data acquisition.

Then the circuits

both digital

(A1) and analog (A2) pnntad circuit twards (FOB) are described. After

a short introduction,

detailed

circuit description is given for each circuit pan.

The various

circuit

descriptions refer to the circuit diagrams in chapter

10.

NOTE: The large digital (A1) and analog (A2) printed circuit board diagrams are provided

separate drawings. Whenever a signal line continues on anofher drawing, it is indicated

the following

comment:

“FROM A

‘

—

> coming

from

the

digital

)

drcuit (figure 10.2)

“TO A2a

“

—

> thesignalcontinuesonthe first circuit diagram ofthe analog

PCB

(figure 10.5)

3.1.2 Location

of electrical parts

The Item numbers of

C.,., R..„ V,.., H.... D... and K... have been divided Into groups. TTiese groups

relate to the functional parts on the PCBs:

Table 3. 1 Location of electrical parts.

Item number Furtctional part

PCB diagram

1200-1299

pP, Oigitaf ASIC and related circuitry

1300-1399

battery sense, RAM power, backlight A1 AT

1400-1499

LCD aryj related circuitry A1

1SOO-1599 ON/OFF circuit

A1 A1

1600-1699

keypad

A1 A1

2100-2199

attenuator channel B

A2 A2a

2200-2299

attenuator channel A

A2 A2a

2300-2399

Analog ASiC and ADC

A2 A2aZb

2500-2599

battery charger

and power supply A2 A2c

2700-2799

EXTemal Input-Zoutpul circuitry

A2 A2b

2800-2899

generator

A2 A2b

2900-2999

analog control circuitry

A2 A2a

Page 32

3-2

CIRCUIT DESCRIPTIONS

3.2 FUNCTIONAL BLOCK

DESCRIPTION

3.2.1 Introduction

This

section contains an overall

block diagram of the ScopeMeter. Refer to figure

3.1

The

block diagram can be divided

in two parts. The upper part of the diagram

shows components

that are situated on the Printed Circuit Board

(In the following text: PCB), that

Is connected to the

ScopeMeter^s

bottom cover. Because this PCB contains

mainly analog circuits, it

called

the analog

A2PCB.

The lower

part of the diagram contains the digital circuitry

of the ScopeMeter. This circuitry Is

located

on the digKal

A1 PCB, the PCB connected to the

ScopeMeter’s lop cover

The general

layout of the block diagram is

the same as the layout of the circuit diagrams

In chapter

10.

The circuits that can be found on the

same circuit diagram (chapter 1

are placed

in a dashed

box in the block

diagram.

Analog A2 PCB The signals

the red

and gray 6NC input connectors are

attenuated Oy the CHANNEL A

ATTENUATOR section and

the CHANNEL B ATTENUATOR. These

attenuators are set by the

Microprocessor (on

the digital A1 PCB) via the ANALOG

CONTROL CIRCUIT. Also input protection

circuits are provided here.

The

output

signals

of the attenuator blocks are fed

to the ANALOG ASIC (ASIC

Application

Specihe

Integrated Circuit).

TNs component is controlled

the

ScopeMeter’s microprocessor (on the digital

A1 PCB). The Analog ASIC incorporates

signal amplification

and channel selection. It also prepares

the signal for sampling

by the Analog to Digital Converter (ADC).

The red and black banana connectors

are connected to the EXTERNAL (BANANA)

INPUT/0UTPUT

CIRCUIT. When the ScopeMeter Is set

mV.

DIODE or OHM METER mode,

the External (banana)

input/output circuit outputs its signal Into

the Channel A Attenuator section.

In SCOPE mode, the

circuit can act as

trigger input. The

trigger signal Is fed to the Analog ASIC.

In the Analog ASIC

"channel A", "channel

B" or "External thggeh' can be selected

trigger

source. The trigger signal is

used to generate the DELTA-

voltage

(time relation between

trigger moment and sampling

momer^t).

The built-in GENERATOR uses the External

(banana) input/output circuitry

output. It is

possible

to generate a DCvoltage and a square wave voltage.

ScopeMeter model 97 also can

generate sine

wave voltages, a ramp voltage, and a ramp current.

Page 33

CIRCUIT DESCRIPTIONS

Page 34

Page 35

3-3

CIRCUIT DIAGRAM

A2c

DATA

(8AHPL6D

DATA

AD0PE6S

DI61TAL

ASIC

-’tiriEaAse

Function

•TAICBER rUNCTION

ACL

-«)N/nAX

•MSt

•DISALAT OONTROI.

BACKLIGHT

CIRCUIT (973

SUfPLI

VOLTAGES

ANALOG A2 PCB

DIGITAL A1 PCB

(C)RCUIT DIAGRAH Al]

ST63S«

9SO?C<

Page 36

3-4

CIRCUIT

DESCRIPTIONS

The power

$upply circuitry Is also

located on the artalog

A2 PCB. The separate Power aPapter/battery

charger PM6907/...

converts

the line voltage Into

15V DC. This voltage

is used by the BATTERY

CHARGER

to Charge a NICad BATTERY

PACK

(PM9086/001

)» if present.

The POWER

SUPPLY section

transforms the input

voltage (fine

operated) or the battery

voltage

(battery

operated) Into

the supply voltages

fjy the various ScopeMeter

circuits

on A1 and A2.

Digital

A1 PCB

The

ScopeMeter Is controlled

by the MICROPROCESSOR

located

on the digital A1 PCB.

This

microprocessor

performs several

control tasks, for

example;

•

Scanning the

KEYPAD for

user commands. The

keypad Is connected

to the microprocessor

via

the KEYPAD

DRIVERS.

Communlcatton

with the

outside world via the

OPTICALLY COUPLED

RS-232-C

TRANSCEIVER.

This

section contains

Infrared

LED (transmitter)

and a photolranslstor

(receiver).

‘

Monitoring

the battery

voltage (BATTERY

SENSE CIRCUIT).

“

Controlling

the Analog

ASIC on the analog

A2 PCB.

•

Switching

the power

on or

off

(POWER ON/OFF CIRCUIT).

•

Performing

a proper RESET

at power on (RESET

CIRCUIT).

•

Controlling

the analog A2 circuits

(via the ANALOG

CONTOOL

CtRCUfT).

•

SIgnal

rocessi

of acq ul red

data. The mlcroproce

ssor reads

calibrate

s and stores the

acqui red

data.

The DIGITAL

ASIC Is the

core of the ScopeMeter's

digital clrcurtry.

It provides:

Timebase

functions. For

example: tfte

ScopeMeter's ADC

sampling signal fs generated

by the

Digital ASIC.

•

Trigger functions

(In real-time

sampling mode).

•

Acquisition Control

Logic (ACL).

This function controls

the acquisition

according to trigger

and

acquisition modes.

The Digital ASIC

contains acquisition

RAM for quick

data storage.

Mln/Maxmode.

•

Decoding of the

Internal ASIC addresses

and synchronization

of Digital

ASIC and microprocessor

access to the

acquisition RAM.

•

Display

control. The Digital

ASIC generates the

picture to be

displayed on the LCD.

The picture,

generated by

the

Digital

ASIC is displayed

on the Liquid Crystal Display

(LCD). The

LCD is controlled

by the LCD ROW

DRIVERS and the

LCD COLUMN

DRIVERS. The

LCD SUPPLY

section provides

for the voltages needed,

ScopeMeter

model 97 has a BACKLIGHT

CIRCUIT, which

can illuminate LCD.

3.2.2 Data acquisition

Data

acquisition

path in the

ScopeMeter

The analog input signals

are first

attenuated and/or

amplified and then converted

into digital values

by the ADC. The samples

of the Input

signals are stored

in the Acquisition

RAM of the Digital

ASIC.

512 samples are stored

in memory, the second

trigger pulse will signal the microprocessor

that the

acquisition Is ready.

(We

assume toatthe

ScopeMeter is using random

repetitive

sampling, see next

section.) Then

the acquired

data is ready for processing.

The microprocessor

reads the

data from the

Acquisition RAM

and processes

the data according

to the actual

calibration values.

These calibration

valuee

(constants) are copied

from Flash

ROM to RAM during

startup. The calibration

values have

been stored in

Flash ROM

during the calibration

process. After

processing, the

data is stored In

the

External

RAMs. These

RAMs also contain

the more static

picture elements, for

example the

grid-,

cursor-

and text data.

Page 37

CIRCUIT DESCRIPTIONS

•

A multitasking

kernel for hardware and software scheduling

Processing

the acquiree data Is only one of the tasks of the microprocessor.

The ScopeMeter uses

multitasking

kernel for hardware and software schedullrig, based on internal

and external Interrupts.

The

microprocessor contains Internal timers, which can

programmed

by the software. One of

these timers is used to generate interrupts,

e.g.

to scan the

keypad

for

depressed or released keys,

Except processing (calibrating) the acquired

data,

the microprocessor

also does mathematical

computatlone and controls the hardware. The multitasking

kernel takes care that every 20 ms of

processing time, a task is Interrupted. This task will then

held

and

rescheduled,

unless it requires

execution

without Interruption, kn this way a variety of user-requested

tasks can be handled quasi-

si muttaneously,

without the user being aware of the heavy loads on the mioroprocsssor.

The display

of the data on

the LCD Is done by the Digital ASIC, also taking part in

the

multitasking

scheme.

Sampling and Triggering

The ScopeMeter

uses two types

sampling, commonly used in many Digital Storage Oscilloscopes:

REAL-TIME SAMPLING and RANDOM

REPETITIVE SAMPLING.

In the real-time sampling mode (time

base settings: 60s/div...1 ^s/dlvj the ScopeMeter lakes

series

of samples from a single period of the

Input

signal.

These samples are later used to reconstruct

the

signal.

During the rsa)-t)me sampling mode, the Digital

ASIC calculates the trigger pulses out of the

acquired data (for timebase settings between 60s/dlv...50ps/div).

For timebase settings between

20 ps/div

and

ps/div. the

triggering

Is done by the Analog ASIC, using analog comparators.

In random repetitive sampling mode,

the ScopeMeter takes a sample from successive cycles in

repetitive signal. These

samples are stored In memory and combined to reconstmet the original

signal.

In this sampling mode, samples are taken from

the input signal at intervals determined by the internal

ScopeMeter clock. Since there Is no time-correlation between

the system's clock and the Incoming

signal, all

samples are taken at random points of the signal. time

between the trigger moment

and the sampling moment

must be tracked to enable reconstruction of the signal from the samples.

This time,

DELTA T, Is generated by the Analog ASIC.

See

section

3.4.5 and figure 3.12.

During random repetitive sampling mode, the ScopeMeter

always uses analog triggering (Analog

ASIC).

Page 38

CIRCUIT DESCRIPTIONS

3.3 DIGITAL CIRCUITS

(A1

3.3.1 Introduction

TTie following paragraphs

describe the

circuits

on the digital At PCB In detail.

Refer to circuit diagram

At (figure 10.2 in chapter

10).

3.3.2 Overview digital circuits

The

digital circuitry of the ScopeM eter can be separated Into three main parts:

Microproceeeor circuitry

•

Digital ASIC

(in the following text: D-ASIC) circuitry

LCD

circuitry

A block diagram,

which clearly shows the connections between these main

parts. Is shown In

figure 3.2

TO/TROM

niOfl ANALOG

ADC ASIC

ST6097 9?02C4

DIGITAL

PCB

tCIRCUIT DIAGRAM ATI

Figure 3.2 Block diegram main parts digital drcuitry

Page 39

3.3 DIQIT4

3.3.1 lntrodU(

The

A1 (figure

3.3.2

Overvie

The

digita

MIcrop

Digital

•

LCDcJ

A block di;

figure

3.2

ANALOG

CONTROL

ASIC CIRCUITS

TO/fRon

FROM ANALOG

AOC

ASIC

Page 40

3-6

Page 41

CIRCUFT DESCRIPTJONJS

3-7

3.3.3 MICROPROCESSOR

circuitry

(p^P)

•

Introduction

The

ScopeMeter is controlled by a single chip microcomputer with on-board

ROM (called Mask ROM

In the following

text). TNs microprocessor controls the

total system operation and communication

between the

ScopeMeter and the outside world (key

pad,

RS*232-0

interface). It also

controls the

communication

between Internal system components.

Detailed circuit

description

See figure 3.2 and

circus diagram A1 (figure 1

0.2).

The ScopeMeter uses

Intet

83C196 microprocessor D1201,

with on-board Mask-programmed

ROM (Mask ROM). This

microprocessor has an S-bIt data

bus and a 16-bit address bus. The lower

B address bits

AO.., A7 are combined with the data

brts (multiplexed data bus). ADDRESS

LATCH

D1210 is used

to separate data bits and address bits.

The microprocessor’s

Mask ROM contains the startup software

and a diagnostic kernel test

(see

chapter 7). It also contains

the software necessary to drive

the serial interface and to clear and

program Rash ROMs.

The two Flash ROMs (FRO

Ms)

D1207

and 01208 contain the

system software. The FROMs are

directly connected to the microprocessor

via the datand address

busses. The

microprocessor

addresses the RAMs via the D-ASIC

(D1203).

The microprocessor

contains five 8-bft I/O ports. Port

and

4 share their bits with the data and

address busses. The

other I/O ports 0,1,2 are used for vanous purposes.

For example: reading

the

keypad, operating tfie RS-232-C interlace,

battery voltage sense,

switching Ihe power on/off, etc.

Keypad

dreuitry

The keypad

circuitry consists of five shift registers,

01601...D1606, each of which

has eight Inputs.

These inputs

are normally kept "high" by

KIJ resistor arrays

conr\ected to the

+SV supply voltage.

Whenever

a key on the keypad Is pressed,

the corresponding line is connected to

ground, resulting

a "low" signal. All signals are clocked into

the shift registers (with the FRONT.CLOCK

and

FRONT.

LATCH signals). Then they

are converted into two signals FRONT

DATA1 (shift registers

D1603, 01604, D1606) and FRONT.OATA2

(D1601 andDl602).

Opi/caity

isolated RS-232-C interface

The serial

communications circuitry, which is built Info

the

microprocessor,

Is used to operate the

infrared (IR) RECEIVER

and TRANSMITTER of the

ScopeMeter. Forthis purposes stripped

version

of the RS-232-C

protocol is used.

Only the TXD

(transmit data) and RXD (receive

data) lines from the RS-232-C standard

are used.

The IR transmitter

LED HI 201 is driven directly

from the TXD-not pin of the microprocessor.

If a

"0"

transmitted, the LED lights.

The IR receiver

uses operational ^plifler

N1301 to power the collector of phototransistor

HI 202. If

any IR light

Is received, the phototransistor will drive VI 207 in

saturation. This results In a "low" RXD

line, interpreted

by the microprocessor as a

'T.

Battery sense circuitry

The battery voltage -V6AT

generated on the analog unit is

amplified by

-2/3

at operational

amplifier

N1301 . The resulting signal

BAT.LEVEL Is connected

to an A/D converter Input of the

microprocessor.

In this way microprocessor

can monitor the battery voltage

level. If the battery

voltage level

drops below 4.4V, the microprocessor

generates the BATTERY LOW

Indication on the

LCD.

Page 42

3-8

CIRCUIT DESCRIPTIONS

Analog ASIC bus The Analog ASIC(A-ASIC D2301, see circuit diagram A2aJA2b, figure 10.5/10.6) orA-ASIC, as used

In the following text, is controlled by tine rncroprocessor. The mtcrc^rocessor uses the signals CDAT,

CCLK and DTAEa,b,c to set the A-ASIC and the attenuator sections on the analog A2 PCB. These

signals toge^er form Ihe CONTROL bus.

Flash ROM type selection

The ScopeMeter hardware allows the usage of different types of Rash RO^/s. The actual Flash ROM

configuration Is indicated by resistors R1222 and R1224.

FLASH ROM CONFIGURATION

F51211X)

The resulting voltage levels

volt, 2.5 vott or

volt) are read directly

the microprocessor A/D

converter inputs.

ON/OFF circuit

The ON^OFF circuit operates almost like a thyristor. When the ON/OFF key Is pressed,

current 1$

drawn from the

baseofVI

503,

via R1 503 and

VI 501

Transistor VI

503 will now start to conduct. This

results in

current through R1507, R1504,

V1502

and R1506. The

signal

POWER.ON will

now

become "high*.

Also transistor

V1 506 will conduct, supplying base current to VI 503 after the ON/OFF

key Is released. The POWER-ON signal will latch "high*. The ON/OFF signal will

high, turning off

VI 506 and VI

503,

the next time the ON/OFF hey Is depressed. The POWER_ON signal will become

"low" and the ScopeMeter power turns 0IF.

RESBTelreuH

The RESETcircuit consists of VI 203,

205,

VI 215,VI

201,

D1205 and related

components. When the ScopeMeter

power Is switched on, the -fSV supply

voltage starts to rise. This causes the

zener diode VI 202 to conduct. After some

time transistor V1 203 also starts to conduct.

R1204 and Cl203form atime delay (see

figure

33).

switch

The RESETsignal now Is buffered by

^ momem

D1 206 and connected with the RESET

Inputs of the microprocessor and the

Figure 3.3 RESET signal timing

D-ASIC circuitry.

After a reset, the voltage on the EA (External Address) input of the microprocessor (pin

14)

is 'high ".

The

Microprocessor

starts up using the

internal

Mask ROM software. Rrsithe Flash ROMs are

checked

to see

If they contain valid software, if this Is

true, ou^ut

6 of

^ip'flop

D1202 is set "low

Now the microprocessor invokes

software reset. Because

the "low** voltage

on the EA input

the microprocessor, the microprocessor will "start up" again, using the external Flash ROM software.

The

reset pulse is blocked

translstcw

201

prevent

the RESET signal from performing a "hard-

reset" on the

microprocessor

agair>, At this software reset, the microprocessor enables the LCD by

means of the signal LCDPWR. Then the buffers that control the LCDcontain valid data.

Resistor(s)

R1222

R1224

Page 43

ClflCUIT

DESCRIPTIONS

3-9

3.3.4

DIGITAL ASIC (D-ASIC) cicultry

Introduction

The Digital Application Specific Integrated Circuit (or

D-ASIC)

D1203

forms the core of the digital

circuitry of the ScopeMeter ail located on the digital A1 PCB.

Many functions are incorporated in this complex CMOS Integrated circuit (see

figure 3.^ on the next

page);

Timebase

•

Trigger

•

Acquisition Corttrol Logic

•

Acquisition RAM

Min/max

Display control

Decodmg and synchronization

DIgItal-to-analog converters ( DAOs

Detailed circuit description:

See figure 3.4 and circuit diagram At (figure 10.2).

The following gives a short description of the separate

parts

of the

D-ASIC, which perform the

functions mentioned above:

Tlmebase

The D-ASIC contains a crystal oscillator, which uses the 25 MHz crystal G1201. An internal

programmable divider generates timebase sign^ TRACK with a frequency from 0.8333 Hz up to 25

MHz (see section 3.4.5). This TRACK signal is used to sample the ScopeMeter input

signals.

Trigg&r

The

trigger

module in the D-ASIC takes

care

all trigger related functions:

•

pre triggering

• post triggering

•

event counting: the time interval corresponding to the trigger delay is Increased by a

programmed number of "evenlB" (trigger level crossings ofihe

external trigger

signal), which must occur before triggering.

•

n-cycle mcxje: trigger level crossings of the input signal are

counted,

and

triggering

occurs

every n'*' crossing

< n < 255). The n-cyde mode can be used as a digilal

trigger hold-off.

In the real-time sampling mode (<

ps^dlv), the D-ASIC determines the trigger moment with digital

comparators. In the quasi-random sampling mode,

the

A-ASIC

determines the trigger moment with

analog comparators.

Page 44

3-10

CIRCUIT DESCRIPTIONS

TO A-ASIC

{If uiatog tiagefinf)

«f Ogim tnpgenngj

Figure 3.4 Schematic

Diagram D-ASIC D1203

Acquisition

Control Logic (ACL)

The ACL controls the analog input circuitry

and the ADC (N2302, see circuit diagram

A2a/A2b, figure

0.5/1 0.6). The ACL also writes the digital representations

of the input signals to the Acquisition RAM

in the 0-ASIC, according to the

selected trigger and acquisition

modes. Before the acquired trace

data is displayed, It is first processed

by the microprocessor. The microprocessor corrects

for offset-

and ampitfication errors, using the calibration

values that are stored In Flash ROM.

In fast timebase positions

the ACL acquires 1024 values.

Then the acquisition Is stopped

and

the

microprocessor

can read the data out of the AcqulSjtior\

RAM. In slow timebase positions the ACL

uses the Acquisition

RAM as a FIFO ®rs!

First

Qut) memory. The microprocessor can

start

reading

the acquired data Immediately after triggering.

Now there is synchronization between

the

ACL and the microprocessor.

If the system uses analog triggering (time

base ^ l^s), the trigger hold-off signal

(HLDOFFN) to the

A-ASIC is generated. In digital triggering

mode, the D-ASIC generates the HLDOUTN signal.

This

signal

1$ fed to the HLDIN input of the D-ASIC, via

R1 211, C1221, R1214 and C1 211.

These

components

generate noise on the HOLDOUTN signal,

which is needed as a random factor in the

Delta- T circuit.

Min/max

The

Mln/max module finds the minimum and maximum value

of the input signals between two time

base pulses, and writes them into the

Acquisition RAM. To detect narrow glitches, the TRACK

signal

(ADC sample frequency) is always 25 Ml-lz

in MirVmax mode.

Page 45

CIRCUIT DESCRIPTIONS 3-11

Di6ptay contra/

This module reads screen data from the External RAMs

(D1

204

and D1

205)

and sends It to the LCD.

it also sends line pulses UNECL

(17

kHz)

and frame pulses FRAME (70 Hz). This screen data,

consisting of for example cursor and grid information,

Is stored In External RAMs as bltplane

information. The trace data

stored

as a value

tor

every vertical line on the LCD. This data is

converted to bitplar^

data and added to the cursor and grid Information. The display control module

also makes It possible

to change the dotsize of the signal displayed and to use dot joining.

Decoding and synchronization (DESY)

The DESY section is the decoder for the D-AStC’s

internal addresses. This module also synchronises

the microprocessor with the D-ASIC's Display control

module, as botii access the same Acquisition

RAM.

DigiW to ana/og converters (DACs)

The DACs module contains

10 one-bft pulse width modulated monotonous DACs, whose resolution

ranges from five to ten bts. The

DACs are used to control level shifting, analog trigger level, LCD

contrast and the generator function (see section 3.4.7).

Externa/ RAMs

The External RAM section consists of two 32K •

SRAMs

(D1204 and D1206). These RAMs contain:

•

wavefonms (stored with the WAVEFORM

key)

•

frontsettings (stored with tiie SETUP key)

bltplane data for the LCD picture

‘

text, to be used on the display

•

data in RECORD mode

data in A versus B modo (A»

t ^

)

•

bltplane data used while making a printout

the screen

Ram Power circuit

The External

RAMs are powered by the RAM Power circuit. The RAM Power circuit

is fed directly by

the batteries, independently

of the main power supply.

The RAM

Power

circuit is a simple oscillator, used

generate

a stabilised voltage -fVRAM out of the

battery voltage -VBAT.

The basic oscillator circuit is ^own in figure 3.5.

-VBAT

Figure

3.5 Osc/7/afor RAM Power circuit

Input B of Schmitt input NAND D1301 is

connected to ground. When the voltage on input

A is

also

low", the ou5>ut C will become "high". Capacitor

Cl 309

will

charge via R1313. After some time

input

A will become 'high", resulting in

"low"

output C.

C^>acitorCi309 will

then discharge via resistor R1313. The generated

output pulses are buffered

and converted i

nto a DC voltage by C1 31

1 ,

C1 31 2 and V1 31 9 . Th

e outp

ut voltag

e +VRAM Is fed back

to the NAND input

A, via several transistors (voltage gap). If the output voltage

-fVRAM has reached

the correct value, trie pulse train at NAND

output C

stopped via this feedback (see figure 3.6). In

Page 46

3-12

CIRCUIT DESCRIPTIONS

this way capacitor C1312 is charged

Just

enough to keep the output voltage -fVRAM at a stable value

{

3V DC).

sie*u

Figure 3. 6 Pulse trein signal on input A ofSchmitt input HAND (Test Point 223)

3.3.5 LCD circuitry

•

Introduction

The LCD used in the ScopeMeter is controlled by six LCD driver integrated circuits. These drivers get

their information (data- and control signals) directly from the D-ASIC. The microprocessor enables

the display when valid data is present.

ScopeMeter

models 93 and 95 use a reflexive LCD.

Model 97

provided

with

atransflexive

LCD

with

a backlight, which can be switched on or off by the user.

•

Detailed circuit description

See figure circuit diagram A1 (figure 10.2),

LCD

The ScopeMeter uses a Super Twisted Nematic Liquid Crystal Display (LCD HI401. see circuit

diagram

A1,

figure

10.2),

with

resolution of 240

240

pixels.

The picture on the LCD screen is written column (vertical line) after column, rather hian row

(horizontal line) after row. The LCD screen is divided horizontally In 3 row-sections, each

pixels

wide and vertically into 3 column-secUons, each

pixels

wide.

LCD drivers

The LCD display is controlled by the D-ASIC, via six LCD drivers:

three LCD row drivers: D1404, D1406, D1407

three LCD column drivers: D1401, D1402, D1403

Description of the LCD drivers lnput-/output signals:

LCD outputs Yt... YSO and X1...XS0

These outputs are connected to the LCD

matrix. Every

column

driver

serves

pixel columns of the

LCD. Every row driver serves

pixel rows. The output signals are staircase

signals,

with

levels

equal to the VI ...V6 voltages.

NOTE: On the ouput ofeveryLCD driver, a Test Point is provided (TP207...TP212). When the driver

is working property, a staircase voltage can be measured on these test points.

•

Data inputs D0...D3 (row drivers only!)

The actual display data coming from the D-ASIC

sent via

the DRIVERBUS

the

LCD

drivers

D0...D3 inputs.

•

Terminai input voitagee V1...V6

Out of these DC signals, with

-20

the

LCD

drivers generate the staircase signals. The input

voltages

Vi...ve

are

generated

die

LCD

supply section.

Page 47

CIRCUIT DESCRIPTIONS 3-

Display

control signals LINECL, DATACL, M, frame

These slQTials are

used to control the LCD. The LCD picture is

constructed from these display control

signals

and the data signals and sent to the LCD via the LCD

outputs.

DATACL is

the clock signal, used to clock the data D0...D3

Into the driver buffer.

LINECL is a clock signal, used to clock

one complete line (column) Into the LCD.

The M signal is described f urtheron

(see

M-randomize

section)

LCD suppiy sectfon

*nte

pulse

modulated signal, CONTRAST, comes from

the D-ASIC. CONTRAST Is filtered by R 1401

and Cl 401

to get a DC voltage. The value of this DC voltage depends

on the duty cycle o1

CONTRAST signal.

Opamps N1401 convert the DC signal Into stabilized

DC voltages VI...V6. If the

signal, LCDPWR, coming

from the D-ASIC, Is "high" (+5V). the -20V voltage

is generated and the

system is active.

The -20V supply voltage is temperature corrected

to compensate for the

temperature

dependency of the LCD (-80 mV/C). The LCD

supply

voltages

have to be corrected by

the same amount to get a constant (over

temperature

range) brightness and contrast of the LCD.

This

temperature compensation is made by Positive

Temperature Coefficient (PTC) R1418. The -20V

voltage Is made out of the -30V voltage, coming

from the analog A2 PCB. Transistors VI 404 and

402

form

a protection circuit, that limits the current

case

the -20V voltage is short circuited.

M-randomi2e sectfon

The signal

M ("LCD backplane modulation') has a time relation with the display

control signals

LINECL and DATACL. The

M-randomize section converts M Into Ml

which

is no longer time related

to the other display

control signals. The M1 signal Is used by the LCD drivers

to convert all DC

voltages into

AC voltages, able to drive the LCD.

Depending on the type (brand) of LCD mounted, integrated circuits

DUOS, 01409 and D1410 or

D1411

are used.

Backlight circuitry

The backlight circuitry is

based on the Hartley oscillator principle. Components VI

307. T1301, and

Cl 302 form the oscillator. Transistor VI 304

supplies current to the circuit. This transistor is switched

orVoff by the ON C^F signal, coming from

dne microprocessor. When the output voltage across the

backlight becomes higher than 100V, tran^slorV1305

will be driven open via VI

308,

309,

and

VI 311 . This wll draw

a\vay

current

(energy) supplied to the oscillating circuit (feedback regulation).

Page 48

3-14

CIRCUIT

DESCRIPTIONS

3,4 ANALOG CIRCUITS

(A2)

3.4.1 Introduction

This paragraph describes the

circuits or> the analog

PCB

in detail. Refer to drcuit diagrams A2a.

A2b, and A2c (figures

10.5, 10.6, and 10.7 in chapter

10).

3.4.2

Overview analog circuits

The

analog A2 PCB contains several

functional parts:

•

circuits

In the acquisition

pati

attenuator

sections

•

EXTernal

(banana) Input/output circuitry

•

Analog

ASIC and AOC circuitry

•

control circuitry

signal generator

• power

supply and battery charger

Each of these

parts will be described

separately. First a short Introduction

is given, followed by

detailed description.

3.4.3 ATTENUATOR

sections, CHANNEL A and

Introduction

See figure 3.7.

The

attenuator sections of

both channels A and B are identical.

In the following only char^nel

A is

described. The corresponcSng

compor>ents for channel B have the

same numboiing, except the

second number, vrfiichis

’T

instead

For example: R2202

in channel A corresponds with

R2102

fn channel B.

The attenuator section

consists of a ntgh frequency (here

after referred to as H.F.)

path and a low

frequency (here after

referred to as LF.) path, which

are combined again in the impedance

converter

(see figure 3.7). To

get a

flat

frequency charactehstlc, both

paths must overlap over

wide

frequency

range.

Circuits are provided for

automatic offset compensation.

The

output of the attenuator sections

of channel A and B is processed

further by the A-ASIC.

Page 49

CIRCUIT

DESCRIPTIONS 3-15

I 1

Figure 3.

Schematic diagram attenuator

section

•

Detailed circuit deacription

See figure 3.7 ar^d circuit diagram A2a (figure 10.4).

input eoupHng

The incoming signal first passes the AC/DC coupling section

(C2202). When re\ay K2201 i$ opened,

the signal is AC coupied via

C2202.

H.F. (high frequency) path

After the coupling section, the L.F, pan of the signal

Olocked

by capacitor C2203. Only the H.F. part

of the input signal enters the H.F. attenuator. This is

triple capacitive divider,

consisting of a 1 to

100, a

to 10. and a 1 to 1.46 divider

The 1

1 .48 divider

section is switched on when relay switches K2202 and K2203

are In the "upper"

position (as shown on circuit diagram A2a, figure 10.5).

The 1 to 1.48 divider cc^sists of C2203 and

C2209

in parallel with

some parasitic capacitors. The

attenuation of 1 .48 times in this straight-on

path

compensated for later in the circuitry.

The separate sections are switched

the signal

path, depending on the attenuation

required:

Table 3.2 Sections used in various attenuator settings.

Attenuator Settings

Sections Used

Attenuation

5 mV/d iv 1 00 mV/di

1.48X 1.48 times

200 mV/div 1 V/dlv 1.48X. 10x

14.8 times

2 V/dlvIO V/div

1.48x, lOOx

148 times

20 V/dlv 1O0 V/div

1.48X.

lOx,

lOOx

1460 times

Page 50

3-16

CIRCUIT DESCRIPTIONS

In the Scope Meter the response of the H.F

attenuator sections is adjusted by means of three variable

capacitors C2209, C2207 and C2114. These variable

capacitors

are

used to compensate for parasitic

capacitors of the printed circuit board.

The 1 to 1.48 divider

to 1.48 section) can

be adjusted with

variable

capacitor C2209.

The 1 to 14.8 divider

to 1 .46 and 1

to 10 sections) can be adjusted with variable capacitor C2207.

The 1 to 148 divider

to 1.48,

1 to 10

and

1 to 100 sections) can be adjusted with capacitor C221 4.

NOTE: These capacitors

do not

have

to be readjusted at every calibration, (see chapters, section

5.6.

The capacitors are rough adjustments,

used to compensate for hardware differences.

The attenuator response is fine adjusted by means of the

LF. caiibration section (see next

page).

Impedance

converter

The output of the H.F. path Is connected with the Impedance converter, formed

by transtsiors V2207

and V2209 (see circuit diagram A2a, figure

10.5). The

bias voltage

of V2207 Is determined by R2216.

To prevent destruction of the gate of V2207 by high voltages or voltage

peaks, two clamps V2206 and

V2204 are provided. Summation of the H R and the L.R signal

parts Is obtained in transistor V2207.

which acts as the collector impedance of V2208.

LF. (Lew frequency) path

The L.F. part of the inptrt signal

enters the L.F. path, which consists of a L.F. attenuator section, a

L.F.

cal bration section

and a regulating feedback loop, which consists of a summator, Inverter, another

summator, and

emitter follower

(see figure 3.7).

L.F. attenuator

Fig 3.8 shows the L.F. attenuator section in detail:

OPPser

vouTAoe

The L.F. attenuator consists of

an inverting amplifier. N2201

which atter>uates the L.F. signal by

factor, depending on the settings

of switches D2201. These switches are controlled by signals named

Srib...Sr4b.

'high" signal switches

the

corresponding latched relays.

Table 3.3 Attenuator drive signals Sr1b...Sr4b.

Attenuator settings Srib Sr2b

Sr3b Attenuation

5 mV/dlv...100 rr>V/dfv high low low 1 -48 times

200 mV/djv...1 V/div high

high low 14.8 times

2V/div...10V/dlv low low

high 148 times

20 V/dlv...100 V/dIv

low high high 1 480 times

Page 51

CIRCUIT DESCRIPTIONS 3-17

The signal Sr4i> operates the switch, which

is used to

ground

the L F. part of the input signal during

offset calibration. This is done automatically to prevent drift.

The offset DAC oircuitry (see figure

3.7)

provides the offset voltage

for

operational

amplifier N2201

The offset compensation

is done automatically by means of the signals So 10b... So14b, coming from

the D-ASIC.

L.R

Calibration

S95a S94s

R2229

-TMHI

—

R2233 R2234 R223R

M 3k83hJ^ 7kS M

7B0EI—

R2231

R2232

Sg7a

Sg6a

R2237

215k

LF and HP attenuation ok

increase LF stgnal part

decrease LF signal part

Figure 3.5 Automatic ad/ustmenf

of the LF. attenuation

Rne adjustment of the L.F. path attenuation Is completed dunng calibration of the

H.F. path

attenuation. This is done by means of a simple 4-bits D>to-A converter, consisting of resistors R222Q,

R2231

R2232. R2233, R2234. R2236. and switches D2202. These switches are operated

sign^s

Sg4a, SgSa,

8960,

and Sg7a, see figure 3.6. Resistors R2229, R2231 end R2232 divide the output

signal of the attenuator

section. Resistors R2233, R2234. and R2236 increase the input resistance

of the Inverting amplifier of the regulating

loop.

Feedback loop

The output signal of the impedance converter is fed back to the Input

of operations!

amplifier

N2201

with the signal com^g from the LF. calibration section (via

R2237) and a DC position voltage (5V via

R2246), proportional with the MOVEment of the trace (via

R2248).

Transistor

V2210 is used to

enlarge

the dynamic range: when D-POSCHA is active, R2270 is incorporated in

the

circuitry.

The feedback loop operates

follows.

If, for example, the output signal of the L.F. path is too small,

the correction amplifier

N2201

will

drive V2207 via V2208. In this way the amplitude of the L.F. path

and the position voltage

are

increased

(compensation).

Input pfoteethn

The input protection safeguards the ScopeUeter against overvoltage. The

Input protection circuit

consists Ot C2203 and V2206A/2204 (damp HF attenuator) and

R2219 and V2212A^221

(clamp LF

attenuator).

Page 52

•

CIRCUIT DESCRIPTIONS

3.4.4 EXTERNAL (BANANA) INPUT/OUTPUT circuitry

•

Introduction

See figure 3.10.

The ScopeMeter Is provided with two Panana connectors, which are used

Inputs In

the mV,

DIODE, and OHM METER modes or as EXTerna I trigger inpirt in SCOPE mode. These connectors

also serve

as outputs for the built-in

generator.

Protection circuitry is provided to prevent damage

overvoltage.

t<27E1a

Text, mv

Figure 3.10 Schematic diagram signal flow fn EXTemaf (banana) input/output circuitry

•

Detailed circuit deacription

See figure 3.1

and circuit diagram A2b (figure

10.6).

mV DC measurement circuitry

The

mV DC input

voltage

on the red banana terminal is

fed

to die L.F. pan of the channel A attenuator

section, via the followng path: R2750, K2750a, K2751 b, R2761

D2751 (refer to circurt diagram A2b,

figure 10.6). M/hen the ScopeMeter is switched to mV DC measurement using the EXT banana

terminals, the settings are

follows:

Table $.4 A-ASIC and attenuator settings in

mode.

RANGE A-ASIC (02301) LF-ATTENUATOR (channel A)

300

100

mV/div

3 V 100 mV/dIv O.V

Page 53

CIRCUIT DESCRIPTIONS

3-19

Ohm measurement

circuitry

n«i9»

Figure

3.11 Ohm measurement

circuitry

(principie of operation)

The resistance

R* to be measured

is connected

as a feedback resistor of

an amplrfier circuit

(opamps

N2761). The output

voltage of this measuring

amplifier Is proportional

to resistance R,:

VoLj.

<Vret''Rrt’'R«

The different ranges

are obtained

by selecting different values

for resistor R,

This

can be done with

ine Ohm range

selection circuit (D2750

and surroundmg resistors),

which Is controlled

by the Analog

Control circuitry (circuit

dagram A2a,

figure 10.5, B-OFFSET

lines).

Table 3.5

Ohm

range

selection

circuit control lines.

RANGE Sc15

Sc16 Set 7

Sole

300Q 1

0 1

3kii

30k£2

0 0

300W2

1 1

3MO

0 1

30MI2

0 1

Switches D2751 choose

between the mV DC

voltage and the voltage

from the Ohm circuit.

The

outputs

of these sv/itches are connected to the

L.F. part of the channel

A attenuator (circuit

diagram

A2a, figure

10.5).

Diode measurement

circuitry

While In DIODE

METER mode, the

ScopeMeter uses the

same circuitry as

In OHM mode.

WARNING:

The BLACK terminal

id not connected

to the BNC grounds,

while in OHM

DIODE METER

mode! While in

OHM er DIODE METER

mode, the ScopeMeter

can

not be grounded

via the BLACK

banana terminal.

EXTernai

trlggerirjg

The trigger

signal is fed to the

A-AStC on A2a (figure 1

0.6)

via resistor

R2750 and voltage divider

R2763/R2754

(see circuit diagram

A2b, figure 10.6). It Is also

possible to trigger

on the signal made

by frie generator.

Then the trigger signal

Is made out of the

Signals STIMUL and

G-OUTP by D2S60.

V2758, and related

components.

Generator

signal

The output

of the generator

(see paragraph

3.4,7) is sent to the EXT

banana terminals via

K2751 b.

K2750a and R2760.

Page 54

3-20

CtRCUIT DESCRIPTIONS

Protection

circuit (generator mode}

if a high voltage

is applied

the banana terminals

A and B, a

current will flow from terminal

through PTC

(Positive Temperature Coefficient)

R2750,

zenerdiodes V2750 or

V2751

and v<a

V2752

and V2753 back to terminal B (see circuit

diagram

A2b,

figure

10.5).

The voltage across

the zener

diodes is limited to 7.5V for each diode. The rest of the input voltage is dropped across R2750. The

resistance of this PTC will rise and

limft

the

current

the

ctrcuit Opamp N2750

drives V2752

and

V2753, to prevent capacitive load of the generator by these zener diodes.

Protection (Ohm and diode

measurement)

If a

high voltage

is put on the EXT banana

terminals, this results In an irn^rease of the voltage over

PTC R2750.

This Increases the value of this PTC, limiting the current In the circuit. Zener diode

V2764 limits the output voltage

the measurtng amplifier arcuit N2751 . Resistor

R2771

and clamp

diodes V2759...V2763 protect the input of the measuring amplifier.

3.4.5 ANALOG ASIC (A-ASIC) and ADC circuitry

Introduction

See

figure 3.12.

The signals coming from the channel A and B attenuators are fed to D2301 . Various oscilloscope

functions are Integrated in this Application Specific Integrated Circuit (ASIC).

Analog ASIC D2301 selects the signal source and prepares the signal for further processing by the

ADC circuitry. Also a trigger signal is derived from one of the channel A or 8 inputs or the external

trigger

input

(banana

connectors).

Detailed circuit

description

See figure 3.12 and circuit

diagram A2a/A2b (figure 10.5/10.6).

First

short description is given for the internal circuits of the A-ASIC. The schematc diagram of the

A-ASIC D2301 is shown in figure 3.12. The A-ASiC input/output signals are also described in the

following sections.

Channei A

Amptifierand Channei B Amptifier

The output signals of the

charmel

and B attenuator sections are amplified In the A>ASIC to obtain

the most

sensitive

ranges.

Table 3.6 A-ASIC relative amplification at varfous attenuator settings.

Attenuator setting: A-ASICrelatIve ampfificatlon:

100 mV/dlv 1 time

mV/div 2 times

20 mV/div 5

times

10 mV/di

10 times

5 mV/div 20

times

mV/div* 10 times

mV/diV 20 times

both 1mV/dlv and 2 mV/div

settings are made by miitiptying times f<ve and averaging the signal in 5 mV/div.

ard 10 mV/div.)

The A-ASIC

itself can handle input signals with a maximum amplitude of 750 mV peak-peak. A

vertical offset voltage YPCS is added to the

signal

the attenuator sections (section 3.4.3). This

means that OV on an A-ASIC input

terminal results In

trace in the vertical middle of the screen.

Page 55

CIRCUIT DESCRIPTIOMS

3-21

Schematic Diagram AASK: OCX)30d

COAT CCLK DTAE

Figure

3. 12 Schematic diagrarrt A-ASIC D2301

Channet

Se/eetor

The channel selector selects channel A or channel B. depending on

the level of the GHANA signal

(Input13).

If CHA is "high*'

3.5 V) channel

A Is

selected.

If CHA is "low"

1.5 V) channel 5 is

selected.

a timebase speed faster

than

|xs is selected, both channels are displayed

In alternate mode and

CHA is a square wave signal

with a timebase-dependent frequency

(see

table

3.7). If a timebase

speed slower than

ps is selected, both channels are displayed In chopped

mode. The CHA signal

is a square wave signal with a trigger-dependent frequency of 500 kH2 maximum.

Page 56

3-22

CIRCUIT DESCRIPTIONS

Table 3.7 Frequencies

of A-ASIC signals In various modes^

Time Base TRACKN freq

CHA freq

MODE

horizontal vertical

60 s/div 0.8333 Hz

0.416 Hz

20 s/drv 2.5 Hz

1.25 Hz roll

10 s/div

5 Hz 2.5 Hz

s/div

10 Hz

2 $/div

25 Hz 12.5 Hz

1 s/dIv

50 Hz 25 Hz

.5 s/div

100 Hz 50 Hz

.2 s/div

250 Hz 125 Hz

s 0

.1 s/div

500 Hz 269 Hz

50 ms/dlv 1 kHz 500 Hz

20 ms/div 2.5 kHz 1.25 kHz

G F

10 ms/div

5 kHz 2.5 kHz L

ms/div

10 kHz

kHz

ms/div 25 kHz 12.5 Id-fz

1 ms/div

50 kHz 25 kHz

.5 ms/div

100 kHz 50 kHz f

•

.2 ms/div 260

kHz 125 kHz Ei

.1 ms/dlv

600 kHz 250 kHz C

ps/div

1 MHz 500 kHz

ps/div

1.25 MHz

“

ps/div

2.5

MHz

ps/div

5 MHz Trigger E

ps/div 12.5

MHz N

ps/dfv 25 MHz

dependent T

ps/div

25 MHz

ps/div

25 MHz

.1 ps/div

25 MHz

50 ns/div 25 MHz 20 ns/div 25 MHz

1 f

10 ns/div 25 MHz

)

In MtN/MAX mod^

(only possible for one channel), the frequency

of CHA is zero and the sample

frequency TRACK Is always

25 MHz.

Clamp

To prevent the

Track & Hold circuit from overdrive,

the signal is damped. The level of the output

signal

can be adjusted by means of VREF

(input 23). VREF is the reference voltage, made

ihe circuit

consisting of V2301, V2302 and R2323,

R2324, and R2325 (see ADC section).

Track A Hold

The maximum sampling frequency

of the ADC used in the ScopeMeter is 25

MHz.

This

means that

the ADC can only handle signals with

frequencies up to 12.5 MHz (half the sample frequency).

Because of this a Track & Hold circuit

incorporated

In the A-ASIC. The Track & Hold circuit

determines the frequency

range of the whole system.

The timing in this part of

the A-ASlC (s determined by clock signal

TRACKN (input 1

2).

The frequency

of the TRACKN signal

depends on the selected timebase

speed (see table 3.7).

Page 57

CIRCUIT DESCRIPTIONS

3-23

The oiitput signal*

SGNOUT, {output 1

fs fed to the ADC.

The voltage range of

SGNOUT )s

,5V,

..3.5V, The

Intermediate level

of SGNOUT is derived

irom the VREF

voltage level, which is

made

the

ADC.

TRACK-

TRACK TRACK

A-AS(C

(defiyM

TRACK-)

TRACK

HOLD

TRACK

SSNOin'

OT A-ASIC

CLMADC

dalayed

oditf

HCUD

TRACK 1

TBATK

1 -An«

ADC lakes sample

Track

& Hoid timing

Externat

Trigger Amplifier

This amplifier

section prcxsesses the

incoming external trigger signal

so that it can be used in

the

trigger section.

The Input of this section

is TTL compatible

Trigger Selector

In this section tne channel

A, channel B or external trigger

input signal is selected

to ad as trigger

source. The trigger slope

is also selected in this

block.

Hysteresis

The hysteresis

section converts the trigger signal

into a pulse shaped

signal. Because of the

hysteresis,

the circuit will not trigger

on noisy signals. The LEVEL signal

(input

20)

that determines

the trigger level>

Is a DC voltage between

+0.5V and +2.0V. The LEVEL signal

Is a DC voltage,

generated in the Digital

ASIC. Resistor R2309 and

capacitors C2312 andC2313 form

alowpass filter,

to convert a pulse width

modulated signal into the DC

voltage.

Detta^T

circuit

The Delta-T

circuit measures

the lime between a trigger pulse

and the moment the input

signal is

sampled. Figure 3.14 shows

the timing diagram with relaton

to the signal HLDF (Input 1

0),

START

(internal), STOPN

(output

9),

and TOUT (output

15).

1$} ir<3

clocX

CtOCA

START: Internal (in

the A-ASIC) start

signal for the

Delta-T

measurement.

TOUT: a voltage

proportional to the

measured

value (time) of

Delta T.

Figure 3.14 Timing

diagram Delta-T

circuH

Control logic

The control logic

section contains

serial-ln

parallel-out shift register.

This section gets

Its data from

the microprocessor

(D1

201,

circuit

diagram A1. figure

10.2) viafrie CDAT (serial

data), CCLK (sertd

clock),

and DTAE (data-latch) lines.

The control logic section

controls ail functional blocks within ttie

A-ASIC,

Page 58

3-24

CIRCUIT DESCRIPTIONS

ADC

The

output

signal SNGOUT (pin

18)

the

A-ASIC Is

fed to the

e-bit Analog

Digital

Converter TDA 8703. This component operates on a 2S MHz clocK signal. The

signal TRACKN Is

delayed to compensate

for the internal

signal delay in ^e A-ASIC (behind the

Track & Hold section) and is fed to ADC pin 17.

The ADC provides for the reference voltage needed by the A-ASIC. This reference voltage is derived

from

the ADC.

V/REF

is made of the

voltages

on pin

(VRB

Reference Bottom Voltage: .5V) and

pen

(VRT

= Reference

Top Vottage: +3.5V) of the ADC. During normal operating conditions this

reference voltage, VREF, is +2.5V {+/-

3-6%,

ref.

ground). VREF is

adjusted

with

potent!

omeler

R2346, marked "OFFSET" andean be measured between TP331

and

ground. The ser>sitivity of

the

ADC is adjusted with B2347, marked "GAIN". These calibrations are described In chapter

section

5.6.1: “Hardware SCOPE Calibration Adjustments

The

8-bit output

the ADC: ADCO.mADC? Is connected to the Digital ASIC on the digital Af PCB.

3.4.6 ANALOG CONTROL CIRCUIT

•

Introduction

See

figure

3.13.

The various sectlor^s

of the ScepeMeter, situated on the analog A2 PCB, are controlled by the

microprocessor on the digital A1 PCB. This is done by means of the CCLK (serial clock), CDAT (serial

data) and DTAE (data-iatch) lines. This bus system creates several control signals, which for example

drive the relays switches in the attenuator sections.

Detailed circuit description

See figure 3.13 and circuit diagram A2a (figure 10.5).

MAJNVOLThfT

OFFSeT-CO«P€NS*TION

LF<CALI9RATK)N

WAVEFOflM SeiKTION

Figure 3. IS Schematic diagram analog control circuitry

RELAYS

swrrCHES

(ATT SECnONi

Each shift register transforms the

serial

signal COAT Into

parallel control signals. This Is done by

means of the serial dock signal CCLK and the data-latch signals DTAEa, DTAEb and DTAEc. The

control circuitry

comprises

two

series

cascaded shift

registers:

D2907-D2908-D2909 (24 signals)

and D2904- 02906(16 aignals).

The signals, that are made by the shift registers, are used:

to control the buffers (D2901 / D2902 / D2903), which drive the relays In the attenuator section.

for offset compensation (A-RANGE and B-RANGE) in the attenuator sections.

•

for

L.F. -calibration (A-OFFSET

and

B-OFFSET)

In the

attenuator

sections.

to select the waveform in the signal generator

section

(sine

wave/squarewave/DC).

•

to drive the buzzer

(beeper).

Page 59

CIRCUrr DESCRIPTIONS

3-25

Relay tables

In the following tables the number

“1"

means "high"

(active) signal.

“0"

means "low“ signal and

means

"can be high or tow (don’t care)".

Channel 6 DC

coupled

K2101 K2102

K2103 K2201 K2202 K2203 K2750 K2751

') lOOmV/dIv 1 0

0 X X X X 0

2) IV/div

1 0 X X X

X 0

lOV/dIv 1

0 1 X

X 0

lOOV/dIv 1 1

1 X X

X 0

GROUND 0 1

1 X X X X 0

Channel BAGcoupled

K2101 K2102 K2103 K2201 K2202 K2203 K2750 K2751

100 mV/dIv

0 0 X X

X X 0

IV/div 0 1 0 X X X

tOV/drv 0 0

1 X X X X 0

lOOV/dfV 0 1

1 X X X X 0

GROUND 0

1 1 X X X

X 0

Channel A DC coupled

K2101 K2102 K2103 K2201 K2202

K2203 K2750 K2751

100

mV/div X

X 1 0 0

X 0

IV/drv X X X 1 1 0

lOV/div X X X 1 0 1

X 0

lOOV/dIv X X X 1

1 1 X 0

GROUND X X X 0 1

1 X 0

Channel A AC

coupled

K2101 K2102 K2103 K2203 K2750

K2751

100 mV/d(v X X X 0 0 0

X 0

1 V/dIv X X X 0

1 0 X 0

lOV/div X X X

0 0 1 X 0

lOOV/dIv X X

X 0 1 1 X 0

GROUND X X

1 1 X 0

Relay information valid for SCOPE attenuator

settings

up to

lOO mV/dIv.

*) Relay

Information valid for SCOPE attenuator settings between 100 mV/dtv and 1 V/div, etc.

Page 60

'26

CIRCUIT DESCRIPTIONS

EXTernal ir^ut

K2101

K2102 K2103 K2201 K2202

K2203 K2750 K2751

Ext. Tng X

X X

X X X

0 0

Generator X

X X X X X

1 0

METER

V DC mode

K2101

K2102 K2103 K2201

K2202 K2203 K2760 K2751

300 mV 0 1

1 1

1 0 X

0 1 1 1

0 1 X

30V

0 1 1

1 1 1

X 0

300V

0 1

1 1 1 1 X

METER

V AC mode

K2101 K2102 K2103 K2201

K2202 K2203 K2750

K2751

300 mV

0 1 1

0 1 0

X 0

0 1 1

0 0

1 X 0

30V 0 1 1

0 1

1 X 0

300V 0 1

1 0 1 1

X 0

METER

V DC + AC mode

K2101

K2102 K2103 K2201

K2202 K2203 K2750

K2751

300 mV

0 1 1

1 1 0

X 0

0 1 1

1 0 1

X 0

30V 1

1 1 1 1

X 0

300V 0 1 1

1 1 1

X 0

METER mV mode

(EXTernal Inputs)

K2101 K2102 K2103 K2201

K2202 K2203

K2750 K2751

300 mV 0 1 1

—

0 0 1 1 0

1 0 0

1 1

Page 61

300 Ohm

KOhm

30 KOhm

300 KOhm

3 MOhm

30 MOhm

Control lines tables

Channel 6 DC coupled

100mV/div

K2103

K2201 K2202 K2203 K2750 K2751

1 0 0 1 1 1 1 0 0 1 1 1 1 0 0 1 1 1

0 0 1 1 1

1 0

0 1 1 1

100V/dlv

GROUND

100mV/dlv

IV/dlv 1

10V/dlv

lOOV/dlv

GROUND

Sr2a Sr3a

0 1

1 1

Sr2a Sr3a

0 0

0 1

1 1

Srib Sr2b Sr3b Sr4b

SgndSa mV OHM

1 1

Sfla Sr2a Sr3a Sr4a|Sgnd8b Srlb Sr2b Si3b

Sr4b Sgnd8a mV OHM

0 0

100 mV/dIv

IV/dlv

lOV/dlv

lOOV/dlv

GROUND

Sr1b

Sr2b

Sr4b SgndSa mV C

0 0 0 0

1 1

0 0 0

IDD

1 1 0 0

0 1 1 1

0 0

1 0

Page 62

3-28

CIRCUIT

DESCRIPTIONS

Channel A AC coupled

lOOmWdiv

1V/div

10V/dlv

10OV/dlv

GROUND

METER V DC mode

METER

VACmod©

METER V DC4-AC mode

METER mV mode (EXTemal Inputs)

Sria Sr2a Sr3a Sr4a SgndSb Srib Sr2b

Sr3b Sr4b SgndSa mV OHM

300 mV

0 0 0 1 1

0 1 1

300V

0 0 0 1 1

1 1 1

Page 63

CIRCUIT

DESCRIPTIONS

3-29

METER 0/

-N-

modes

Sr1a Sr2a Sr3a Sr4a SgndBb Srib

Sr3b

Sf4b

SgndSa mV OHM

300 Ohm 0 0 0 t 1 0 0

1 1 0

3 KOhm

0 0 1 1

1 1 0 1

30 KOhm

DDD

1 1

0 0 1 1

300 KOhm

1 1 0 0 0 1 1 0 1

3MOhm 0 0 0

1 0 0 0

1 1

30 MOhm

0 0

1 0

1 0 1 1

Diode 0 0 0

1 0

Scl5 Scie Sc17 Scia

300 Ohm

0 1 1

3 KOhm 1

30 KOhm

0 0 0

300 KOhm 1 1 0 0

3 MOhm

30 MOhm

D Oa

Diode

—

“I

1 0 1 1

BUZ

Buzzer off 1 Buzzer on 0

G.OUTP

Ext. Trig. 0

Generator 1

SCOPE mode

Attenuator settings

METER mode

20 mV/dlv 5 lOmV/dlv

D-POSCHA 0 1 1 D-POSCHB 1 1 X

While the Scope

Meter Is operating

METER mode or when the Instrument Is calibrated, the signals

SI, mV, OHM, Srib, Sr2b, St3b, Sr4b, and D.POSCHB can

change ("hlgn/tow"). signals Ex and Ey

are used to switch the relays. Both signals

are "high*

when

the relays are not operated.

Signals

Sg4a, Sg5a, Sg6a,

and SgTasetthe LF. gain for channel A. Sg^, SgSb, Sg6b, and Sg7b

set the LF. gain for charnel B. (Sg4b) Is the most significant bit (MSB), Sg7a (Sg7b) Is the

least

slgr^lfleant bit (LSB).

Signals Sol Ob, Sot 1b, SOI2b, Sol 3b, and So14b are used to set the offset compensation In the

preamplifier circuits of channel A. Signals Sc15, Sc16, Sc

17,

Sc18, and SO 14a are used to set the

offset

compensation

in the preamplifier circuits of channel B. SOI Ob (Sets) is the most slgr^flcant bit

(MSB), Sol4b (Sol 4a) is the

least significant bit (LSB).

Page 64

3-30

CIRCUIT DESCRIPTIONS

3.4.7

GENERATOR circuit

•

Introduction

See figure 3.14.

The

ScopeMeter has a bullt-ln signal

generator, which can produce

the following signals, used to

adjust the probes:

•

square wave voltage.

amplitude:

frequency:

•

DC voltage: 3V

ScopeMeter model 97

can also produce:

‘

sine wave voltages,

ampiItu

frequency:

square wave voltages,

amplitude:

frequencies:

slow ramp voltage,

-2V...+2V

slow ramp current.

-3

mA,..43mA

5V peak-to-peak

976 Hz

5V peak-to-peak

976 Hz

5V peak-to-peak

488 Hz

1-95

kHz

The signal generator

uses a square wave voltage,

coming from the D-ASIC to generate

the various

signals. The circuit

consists of an operational amplifier,

a fourth order filter,

and a current source. The

configuration can

be changed by means

programmable

switches to produce

different output

signals.

Detailed circuit

description

See figure 3.16 and circuit

diagram A2b (figure

10,6).

Figure 3.16 shows the basic

generator circuitry:

••5V

Figure 3.

16 Basic generator circuitry

This circuft uses a square

wave voltage, STIMUL, coming

from the D-ASIC. This signal has

amplitude between OV and

+5V. The duty cycle of

the square wave signal Is varied

depending on the

signal to be generated.

The reference voltage +Vref

is used to generate the DC voltage.

Page 65

CIRCUIT DESCRIPTIONS 3-31

The configuration depends on

the settings of switches D2650 and D2751. These switches are

controlled by the signals FILT CALDC- HD, SQUAR and Si. Table 3.8 lists ttie various settings and

resulting generator

output

signals.

Table 3.8 Generator control signals for various generator output signals.

STIMUL CONTROL SIGNALS OUTPUT

SIGNAL

frequency duty CALDC- RLT SCXJAR SI amplitude waveform

cycle HD

488 Hz 50% 0 0 1 1 976 Mz 50% 0 0 1 1 Square wave vonage

1.95 KKz 50% 0 0 1 1

1 0 0 1 3Vp-p DC voltage

976 Hz 50% 0

1 1

1 Vp-p Sine wave voltage

20 kHz

0-100%

0 1 0 1

•2...+2VP-P

Slow ramp voltage

kHz 0-100%

0 1 0 0 0...+3 mA Slow ramp current

In this table "V means: signal "high* (switch closed) and

*'0"

means signal

"low*

(switch open).

The slow ramp current signal is made with a current source. A simplified

schema^c

diagram

given

in figure 3.17;

Figure 3.17 Current source section ofgenerator

When

the duty

cycle

of STIMUL Is0%, the bridge will be In balance and current

0. When the duty

cycle of STIMUL1$increased,

a DC component is generated, which has a linear relation to the duty

cycle. The operational amplifier

tries to keep the voltages on both inputs the same. The operatbr>a{

amplifier will now drive trana'stor

V2854 to Increase

1^.

Because Is almost equal to the output

current will also

Increase. In this way it is possible to regulate the current i^ by means of the duty cycle

STIMUL.

Page 66

3-32

CIRCUIT DESCRIPTIONS

3.4.8 BATTERY

CHARGER

Introduction

Seo figufG 3.18.

The battery charger consists

of a switched mode power supply and some auxiliary clrculiry.

Whenever the

Scope

Meter

Is connected to the line voltage (via the separ^e power adapter/battery

charger PM6907), the instrument switches

over to line voltage operation automatically. If a NiCd

battery pack Is Installed, the ScopeMeter wilt charge

this If line voltage Is present. Special circuitry

prevents discharge of the batteries when the Instrument Is

not

being

used.

Detailed circuit description

See figure 3.18 and circuit diagram

A2c

(figure

1 0.7).

HFFitter

The input

voltage (between 8V and 20V) first passes MF FILTER Z2501 and is used to diive

a flyback

converter.

POWffi SUPPLY

Figure 3. 16 Schematic diagram

battery charger

Une voitage detection

When the ScopeMeter is operated on line voltage, transistor V2521 will

driven

by the (filtered)

Input voltage. The signal MAINVOLTHT will become "low" to indicate that the Instrument is operated

from

the line voltage. The related signal MAINS-D (connector XI

201,

connected to the

microprocessor analog input 19. When the signal MAINS-0 Is "high", the microprocessor will

not

switch off the ScopeMeter, as in battery operated mode.

Page 67

CIRCUIT DESCRIPTIONS 3-33

F/ybeck ccn verier

See ligure 3.19 and circuit diagram

A2c (figure 107).

The main components of this

flyDack converter are V2532 (convener-switch), L2504 and L2505

(windings), R2582

(sense

resistor),

and G2536 and V2533 (secondary circuit). The main regulating

element is N2503 (see figure 3.19),

-VcH

Figure 3. 19 Schematic diagram flyback converter

N2503 incorporates an oscillator, the frequency of which is determined by R2548 and C2527 (fixed

frequency of 100 kHz), This oscillator drives

a sawtooth generator. The produced sawtooth voltage

is compared to a DC voltage. This DC

voltage

made by ar; internal error amplifier (voltage

regulator), which compares the produced converter voltage >V_CH to

stable 5V referencevoltage.

This Is done with a bridge circuit (R2564, R2555, R2S57,

R2568).

Figure 3.20 IntemaJ N2503 voltage waveforms

When the sawtooth voltage

larger

than the DC voltage, the output signal (CA. CB on pins 12,13)

is "high

When the sasvtooth voltage is less

than the DC voltage, the ou4>u1 signal is "low"'. In this

way the duty cycle of

N2503’s output signal can be changed, thus changing the energy transferred

to the secondary converter circuit.

The output signal is level shifted by transistor V2526 and related circuitry. Now this square wave

signal is used to drive converter switch V2S32, which is bootstrapped via V2526,

V2529, R2546,

R2562, and C2537.

Charging current limiter

N2503 limits the voltage difference between

CL+ (pin

and CL- (pin

to 200 mV. If the voltage

between these two inputs starts to rise, the irxtamaf

voHage

will rise, and the duty cycle of the

output square wave voltage will decrease

(see

voltage regulation

described earlier).

Page 68

3*34

CIRCUIT DESCRIPTIONS

If th 0 ScopeMeter

is connected

to the line voltage and is

not operallonaJ, the flyback

converter

operates almost

wrthoiJt a load (only

the NICd battery

pack). This irr^plies that

the current floating

through windings

L2504 and

L2505 (averaged In time) is almost

zero. Because of this,

the voltage on

CL+ Is about

30 mA and the voltage on

CL- Is about 170

mV. The battery

pack will be charged with

170 mA.

If the flyback

converter Is operated

normally

(ScopeMeter "ON"), the voltage

on both CL- and

CL+

will rise and the charging current will

decrease to

100 mA.

Battery charge

protection

To prevent charging

of non -rechargeable

batteries, a special

protection circuit Is provided.

For safety

reasons, this circuit

consists of two cascaded

sections. When the

ScopeMeter Is "ON",

the

flyback

converter will

be operative. The produced

voltage POWER-ON

will drive both Feld Effect

Transistors

V2537 and V2538

Open (conductive) via

R2568 and R2569.

Now the battery plus contact

connected

to the ScopeMeter clrcuH

ground, if line voltage

Is present, the voltage -VCH produced

the flyback

converter will drive V2534

and V2536, which

prevent transistcfs

V2537 and V2638 from

conducting. The battery plus

contact is disconnected

from ground.

Power ON/OFF

circuitry

During normal operation

the POWER-ON signal

Is-hSV. Transistor

V2542 Is opened

(conductive), so

•Vbat/s equals

-V.CH. If me ScopeMeter

Is operating and me RESPOWHT

(

'reset power

si^>ply")

becomes "high".

V2541 will conduct and V4542 will

stop conducting.

This will disconnect -VbaVs

from

•V_CH.

3.4.9 POWERSUPPLY

•

Introduction

See figure 3.19.

Different

supply voltages are needed for

various ScopeMeter

sections. A second flyback

converter Is

used to convert -V Dal's to

supply

voltages

of -30V, -5V

and -fSV. This voltage, -VbaVs,

is made by the

first flyback

converter (In the battery

charger section)

or comes from the batteries.

-Vbat/s Is 5V If

operated with NICad battery

pack, and 8V if operated

from line voltage.

Detailed circuit

description

See figure

3.19 and circuit diagram A2c (figure

10.7).

|s»g»iairycrait8Tl

Page 69

CIRCUIT DESCRIPTIONS 3-35

This self-oscillating flyback converter consists

of:

•

V2509 (converter-switch)

R2509...R2517 (sense-resistors)

•

V2502 (thyristor svsotch)

•

R2544 (Start-up resistor)

T2501 (windings)

3 separate secondary circuits

for -30V, -5V, and +5V

The main regulating component Is operational

ampIlfierN2501. This op-

amp

compares

the produced

secondary *SV voltage with a rofarence voltage,

produced by zener diode N2502. If the secondary

•(•SV

increases,

the fault signal generatedbythe

N25Q1

will

produce a current that causes an extra

voltage drop

over R2508. Because of this, thyristor

V2502 will fire earlier. The switching frequency Of

the flyback

converter Inaeases and the secondary

-t-5 V voltage decreases.

When the ScopeMeler Is switched on

(RSSLSTN is "active low'), V2544

(see

circuit

diagram A2c,

figure

10.6)

connects the Inverting Input

of N2501 to ground. When the ScopeMeler starts

up,

capacitor

C2509 causes the reference voltage and therefore the output voltage,

rise

^owly, limiting

the Inrush ("starting') current drawn from the

batteries or line voltage.

Undervottage

detection and protection circuit

When

the

flyback

converter is oscillating, capacitor

C2532 is charged every period via R2543

and

V2516. During normal

operation C2532 Is discharged

by V2517, which Is driven via R2641, V2511,

R2529, and

V2509. If, for example, the secondary

+5V voltage becomes too low,

C2532 ts not

discharged

by V2517. This will activate the RESPOWHT

signal, and the

povsrer

wllf be switched off

compietely, preventing further damage

circuits.

(The +5V voltage can become too

low because the

Input voltage

-VbaVs Is too low. or the power output to the ScopeMeler circuitry Is too high.)

R2542,

C2531,and diode V2508 will reset C2532 during

the start up of the power supply (the voltage

across

C2532

will

become zero). This is necessary because

V251 7 cannot be driven via V2541,

just

after the ScopeMeler

Is switched on.

Reference source

The reference source provides

a stable positive (-t-Vref) and

negative reference voltage (-Vref)

used

in other parts

of the ScopeMeter. It also uses the voltage

across zener diode N2502 as an input

voltage.

NOTE: The flyback

converter, used in the battery

charger seot/on (section

3.4.8)

has

fixed

osdllating frequency

of 100 kHz. The amount of

energy supplied is regulated by varying the

duty cycle. The

flyback converter used in this power

supply, however, Is seff^scUlatlng and

operates on a variable

oscillating frequency and a fixed duty

cycle. For alkaline batteries, for

example, the oscillating frequency

s about 62 kHz.

Page 70

PERFORMANCE

VERIFICATrON PROCEDURE 4-1

4 PERFORMANCE

VERIFICATION PROCEDURE

4.1 GENERAL

INFORMATION

The ScopeMeter should be calibrated and

In operating condition when you receive It.

The following

perfcxmance tests are provided to ensure

that the Scope Meter is in a proper operating

conditior>.

If the

Instrument

fails any of the performance tests, calibration

adjustments (see chapter

and/or repair

(see chapter

is necessary.

The Performance

Verification Procedure described here consists of

two parts:

•

Standard Performance

Verification Procedure

(separate SCOPE* and METER*sectlon)

Additional Performance Verification Procedure

The Standard

Performance Verlficalion Procedure uses built-in

ScopeMeter front panel settings

or frontsetlings, that

can be accessed via the SERVICE MENU. To enter the

SERVICE MENU, press

t»th AC/DC/QROUND

keys simuttaneously. This menu allows you to choose

between SCOPE and

METER performance testing

("Verify").

Vrms

0.058

V DC

+0.012

CHANNEL A

AUlO

RANGE

10:1

30\

300V

2£kV

lOOms/ACQ

SERVICE:

V9fity CALIBRATE

SCOPE METER

ScopeMetar

EXIT

Figure 4.

Service

lA/hen the Scope Meter

is in SERVICE mode, only the softkeys, the select/adjust

keys and the

ON/OFF

key can be operated.

Is possible to move forward or backward through

the

frontsettings,

that apply tc the separate

performance

test steps. This can be done using the

adjust/select keys. You can leave the

Performance

Verification Procedure any time

pressing

the EXIT softkey. The Performance

Veiificallon

Procedure steps are explained in the following sections.

Page 71

4-2

PERFORMANCE VERIFICATION

PROCEDURE

The Additional

Performance Verification Procedure

can be used to do some extra

checks,

depending

on the Scope Meter version

(93, 95or97).

these tests the ScopeMeter must

be set up

manually.

NOTE:

This Performance Verification Procedure

is a quick way to check most

the

instrument's

specifications. Because of the highly integrated design

of the ScopeMeter. it is not always

necessary to check ail features

separately. The procedure described here

often combines

many test steps in one procedure

step, thereby minimizing totaJ test time.

The

Performance

Verif/cation Procedure

is based on the specifications, listedin chapter

this Service

Manual. The values (requirements) given

here are valid for ambient

temperatures

between idCandZBC.

4.2

STANDARD PERFORMANCE

VERIFICATION PROCEDURE

This section explains the required

Performance Verification Procedure

setup, with the actions that

have to be done for each step. Follow

the

instructions

described with each

step.

The

recommended test equipment, required

for this Standard Performance Verification

Procedure, is

listed

In table 4.1.

Table 4. 1 Recommended test

equipment Standard Performance Verification Procedure

Instrument

Type Recommended Model

Multifunction

Calibrator

Fluke 5100B

Function Generator

Philips PM 5134

Time

Mark Generator Tektronix

501

Constant Amplitude

Sine

wave Generator

Tektronix

SG 503

Square wave

Calibration Generator

Tektronix PQ 506

•

Cables and terminations for

the generators (all BNCtype)

•

Two standard banana test leads (delivered

with the ScopeMeter)

•

BNC (fern ale)-to-banar\a

(male) (delivered with the ScopeMeter)

NOTE: During

the following Performance Verification Procedure,

the ScopeMeter ir\put sockets are

connected

the

signal generator outputs by

means of cables (BNC connector channei A or

B) or two

standard banana test leads (COM

and mV/Ohm/Dlode banana connectors). The

oscilloscope probes delivered with

the instrument are not

used

during

the Standard

Performance Verihcaticn

Procedure. The calibration of the probes

described

in the Users

Manual.

In the following text,

this figure Is used to indicate that one

of the

selecVadjust

keys

(up/down) must be pressed, to display the Indicated

step number “x" on the

ScopeMeter screen.

Page 72

PERFORMANCE

VERIFICATION PROCEDURE

4-3

^/2

. LCD test

While In the SERVICE menu, press the SCOPE softkey to enter the

SCOPE section of the

Performance

Verification Procedure.

Now a (dark) test pattern

is displayed. This pattern consists of a circle placed

a square, and a diagonal line (see figure

4.2).

Observe the

test pattern closely. The lines may not be

Interrupted;

the pattern must be continuous. In this

test

sets the c^splay to a high contrast, resulting

In a

dark

display. If there are defects In the pixel columns of the

Liquid

Crystal Display, they must be clearly visible now

Intermissions

In the pattern.

After you have checked

the display, press the upper

select/adjust key

once. Now an oscilloscope screen is

displayed.

Figure

4.2 Test pattern

Press the upper select/adjust key again

to go to step 2. Now the display shows

the same pattern, but with

low

contrast (bright screen). This will help you to

locate any failures in

the

pixel

rows of the LCD.

3. Ground level check

Pressthe upperselect/adj

st key

go to step 3. The purpose of this

step is to check the

ground level

position

ddjusiments (OV) for both

traces. The

ScopeMeter display

shows

3",

to show

that this is the third

SCOPE

Performance Verificatron

step (see

figure 4.3).

Requirements:

A tOOmV OND B tOOfnV QNO

lOOus/OV Trig:A/

ser'VICE

—

Verity

CALIBRATE

METER EiU ScopeMeter EXrT

Figure 4.3 Reference set-up

Venfy thal the traces of both channels A and

B are

situated

on the vertical middle of the screen.

Page 73

4-4

PERFORMANCE VERIFICATION PROCEDURE

4. Vertical deflection coefficients channei A

These tests check the vertical deflection coefficients for cttannel A in the

100 mV/div DC and

ranges.

Test ec^uipment:

Fluke 5100B Calibrator

Test setup:

Procedure/requlremente for AC teat:

A Apply

1 kHz sine wave signal with an amplitude of 600 mV AC peak-to-peak to the channel A

BNC connector.

(Set the Fluke 5100B to 212.13 mV RMS, 1 kHz sine wave).

Verify that the amplitude of the sine wave signal dieolayed is 5.68...6.12 divisions.

Procedure/requirements DC test:

Apply

300

mV DC to channel A.

Verify that the distance between the trace for channel A and the vertical middle of the screen

(ground level) Id 2.94.. .3.06 divisions.

5/6/7. Vertical deflection coefficients ctiannel D

These tests check the vertical deflection coefficients for channel 6 In the DC and

ranges.

Test equipment:

Fluke

5100B Calibrator

Page 74

PERFORMANCE VERIRCATION PROCEDURE

4.5

Test setup;

Procedure/requirements for channel 6 AC and DC tests:

A Apply 300 mV DC to Channel 6. 6

Change the input voltage and the setting of chanrtet B according to table 4.2 and check that the

amplitude of the signal agrees wi^ the value fisted

Use the setect/adjust keys to select each

step number.

NOTE: The AC voltages listed in this are peak-ta-peak voltages (sine wave). The values listed

between brackets

()

are the RMS values that have to be chosen on the Fluke 51008

calibrator.

Requirements:

Table 4.2 Requirements verlicai deflection coefficients for channel B.

Input voltage

Step

number on display Requirements

300 mV DC

"5"

2.94...3.06 div.

600 mV AC

(212.13mV RMS). 1 kHz

-5-

5.88...6-12div.

3VDC

"6"

2.94...3.06 dIv.

eVACpp (2.1213V RMS), 1 kHz

•6"

5.88...6.12div.

30V

"7"

2.94...3.06 div.

60V AC (21.213 V RMS), 1 kHz

'7'

5.88...6.12 div.

The ScopeMeter uses the same input drcultry (hardware) for the SCOPE and the METER modes (In

the above attenuator settings). When the voltage accuracy is checked (see the description "METER

Performance Verification Procedure" step

1).

the deflection coefficients for SCOPE channel A are

also tested.

8/9.

Rise time

The rise lime of the ScopeMeter is checked by means of a fast rise time pulse.

First channel B Is measured.

Test equipment:

Tektronix PQ 506 Square Wave Calibration Generator

Page 75

PERFORMANJCE

VERIFICATION PROCEDURE

Tost setup channel

6 rise Hme measurement:

Proce<iiire

for channel B rise time

measurement:

Apply

a fast rise time pulse,

repetition frequency 1 MHz, amplitude

0.5V to channel B.

Use a 50Q

termination.

SetUie generator In

position “FAST RISE*.

B Adjust the pulse

am^^ltude to exactly

5 divisions. See figure 4.4.

Requirements:

A/OTE;

i^( measured)

= Inputsigriaf)^+ t^{

ScopeMeter)

C Check the

rise time, measured between

10% and 90% of the pulse

amplitude. See figure 4.4.

The rise time

t^ {measured) must

be 7

(0.7 div) or less.

Figure 4.4

Rise time <o,7div

blbVm

Test setup

channel A rise time measurement:

Refer

to the test set-up for channel B

measurement. Connect the pulse

generator

to the channel A BNC Input connector.

Page 76

PERFORMANCE VERIFICATION PROCEDURE

4-7

Proc^durd for channel A rice time meaaurament:

Refer to the settings/procedure for channel B

measurement.

Requirements:

Refer to channel B requirements.

10/11/12/13. Frequency response

These tests check the upper transition point of the bandwidth for ScopeMeter

vertical channels Aand B.

Test equipment:

Tektronix SG 503 Constant Amplitude Sine wave Generator

Test setup:

Procedure/requirements for channel A frequency response

measurement:

A Apply a 50 kHz sine wave with an amplitude of 120 mV peak-to-

peak to channel A. Use a 501^

termination.

Adjust the input signal to a trace height of exactly 6 divisions.

B Without changing the amplitude of the sine

wave

signal,

switch over to

step 1 1 using the upper select/adjust key. Increase

the frequency of the sine

wave to 50 MHz and venfy that the vertical

deflection is 4.2 divisions or more.

Procedure/requiremente for channel B frequency response measurement!

C Apply a

kHz sine wave with

an amplitude of 1 20 mV peak-to- peak to

channel B. Use a SOiZ termination.

Adjust me input signal to a trace height

exactly

divisions.

0 Without changing the amplitude of the sine wave signal,

switch over to

step 13 using the upperselect/adjust

key. Increase the frequency of the sine

wave to 50 MHz and check

that

the

vertical deflection is 4.2 divisions or

more.

Page 77

4-8

PERFORMANCE VERIFICATICMM

PROCEDURE

14/15/16/17. Trigger

sensitivity channel

A and B

The trigger

sensitivity depends on the

amplitude and frequency

the

trigger

signal. This

test checks the trigger

sensitivity of the ScopeMeter. Also

the

•hSLOPE/>SLOPE furrction

(triggering on negative slope) 1$

tested for both

channels

A and B. Channel

tested first.

Test equipment:

Tektronix

SG 503 Constant Amplitude Sine Wave

Generator

Test setup:

Procedure/requlrementsfor

channel B trigger

seneftivHy measurement:

A Apply 3 100 MH2 sine wave, with an amplitude of approximately

500 mV peak'to-peak

channel B.

Use a 50Q termination.

6 Adjust the

amplitude of the input signal to exactly 4 divisions

on the display.

C Verify that

the signal Is well triggered.

D Apply

8 60 MHz sine wave, with an amplitude of

approximately 1 00 mV peaK-io-peak

channel B. Use a 500 termination.

£ Adjust the amplitude of the Input signal

to exactly 1 .5 divisions on the display.

F Verify

that the signal Is well triggered.

G Apply a 10 MHz sine wave.

wHh an amplitude of 300 mV

peak-to-peak to

channel 8. Use

500 termination.

H Adjust the amplitude of the Input

signal to exactly 1 .5 divisions, on the display.

I Verify that the signal

is well triggered on the falling edge.

See figure 4.5.

Figure 4.5 S/gnai triggered

on the failing (negative)

edge

Page 78

PERFORMANCE VERIFICATION PROCEDURE 4-9

Procedure/requirements for channel A trigger eensitivlty measurement:

K Repeat

steps G,.. I

for

channel A,

L Repeat steps A...F for channel

18. Timebase

This test uses a marker pulse calibration signal to verify the deflection coefficient

of the time base.

Test equipment:

Tektronix TG 501 Time Mark Generator

Teat set-up:

ScopsMeter

Procedure/requirementa:

Apply

a1ps

peaMo>peak) time marker signal to channel A. Use a 50A termination.

B Verify

that the distance between the 1

0*^

marker pulse and the

10^

vertical grid line is the same

as the distance between the

marker pulse and the

2"^

vertical grid line.

(Tolerance

pixel

± 0.04 divisions).

F/gure

4. 6 The Ofstance Oetween the

70'*

marker pulse the werttcat grkS Une must he the

same

as the distance between the

2”®

marker pt^se and the

vertical grid line.

Page 79

•

PERFORMANCE

VERJFJCATION PROCEDURE

19. Trigger

sensitivity externai

channei

This test checks

the trigger sensitivity, using

the trigger

input.

Test equipment:

Phiiips PM 5134 Fur>clion

Generator

Test setup:

Procedure/requiremants:

A Apply a 1 kHz sine wave signal,

that has an amplitude

of 1 .2 V peak-to-peak, superimposed

.4V DC to channei A and

to the banana input sockets.

U&e a coaxial signal spiitter and a BNC*

tO'banana converter

(see test setup).

Use 50Q terminations.

G Verify that the signal

is well triggered.

CTirn

Figure 4.7

1.2V peak-to-peak sine wa

superimposed

on 1.4VDC

20. Horizontai

deflection: x-deflection

TNs test checks the correct

working of the X-Y (A versus

B) mode.

Test equipment:

Philips PM 5134

Function Generator

Page 80

PERFORMANCE VERIFICATION PROCEDURE 4-

Test set-up:

Procedure:

A Apply

2 kHz sine

wave signal of 800 mV peak-to-peaK to channel A and channel B.

Use 50^

terminations.

Adjust the Input signal to

a trace height of 8 divisions.

Requirements:

Verify that

line with

an angle of

45°

is displayed.

See

figure 4.8.

Figure 4.8

A versus 8

display

21/22. Base line instability

This test checks the maximum

base line

instability.

Teat equipment:

none

Test setup:

no special

setup

required

Page 81

4-12

PERFORMANCE VERIFICATION PROCEDURE

Procedure/roq

uirem^nts

A Turn off the signal sources connected to the ScopeMeler input or minimize

(zero) the signal amplitudes.

B Use the select/adjust keys to switch from front setting

number

to number

22 and back to 21.

C Verify that

the

trace

does not jump more than 0.1 divisions while switching

between front settings 21 and 22.

While in the SERVICE menu, press the

METER softkey to enter the METER part of the

Perfomiance Verification Procedure.

1. Voltage accuracy METER

mode

The lollowir^ section checks the voltage accuracy In METER mode. The

ScopeMeter

uses the same input circuitry (hardware) for the SCOPE (channel A)

and

the

METER modes (In these attenuator settings). When the voltage accuracy

of the METER

1$ checked, the deflection coefficients for SCOPE channel A are

also tested.

Test equipment:

Fluke 51 OOB Calibrator

Test setup:

SeopeMeWf

Procedure:

A Apply 300 mV DC to channel A. B Change the input voltage and the setting

channel

A according to t^le 4.3 and check that the

amplitude of the signal

agrees

with

the value listed.

NOTE: TheScop&M^teris

s&t to METER "AUTORANGE^ (st&p

w/th a dual (AC and DC) readout.

This implies

that

the

ScopeMeter range is set automaiicaHy according to the input signal.

Page 82

PERFORMANCE VERIFICATION PROCEDURE

4-13

Requirements:

TaOle 4.3 Requirements for voltage accuracy test channel A. METER mode.

input signal

Requirements

300 mV DC 300 mV RMS AC. 1 kHz

3V DC 3V RMS AC, 1 kHz

30V DC

30V

RMS

AC,

1 kHz

298-0... 302.0V DC

292.5..

. 307.5V RMS AC

2.980..

.3.020V DC

2.925.-.3.075V RMS AC

29-80.-,

3O.20V

29.25..

.30.75V RMS AC

2. DC mV accuracy METER mode

These tests check the accuracy of the DC mV function. The signal must be

supplied 1o the banana input connectors

the

ScopaMeter.

Test equipment;

Fluke 5 1006 Catibralor

Test setup:

Seop«Meter

Procedure/requI rementa:

A Apply 300 mV DC to the banana connectors of the ScopeMeter. B Verify that the readout is between 298 .2...30 1

mV DC.

Apply 3V DC

the banana connectors of the

ScopeMeter.

D Verify that the readout is between 2.982...3.0 18V DC.

3. Resistance accuracy

These tests check the accuracy of the resistance measurement function, The

signal

has to be supplied to the

banar^a

input connectors of the ScopeMeter.

Page 83

4-14

PERFORMANCE VERIFICATION

PROCEDURE

Test equipment:

Fluke 51

006 Calibrator

Test

setup:

ScQp«M«ter

Procedure/requirements

for resi^nce

function accuracy test:

A Set the Fluke

5100B to 1 0Oa

Check that the readout is between

99.00... 1 01 .OCl

C Set the Fluke 510OB to

D Check that the readout Is

between 9.900...10.10 MO.

4. Diode test accuracy

This test checks the

accuracy of the Diode test function.

Test equipment:

Fluke

51006 Calibrator

Test setup:

SccwMeter

Page 84

PERFORMANCE VERIFICATION PROCEDURE

4-15

Procedure/requlrementa for diode accuracy teatt

A Set the Fluke 5100B to 1 kn.

B Che<3< that the readout is between 0.420...0.569V DC.

Signal display

and frequency measurement

This test checks the waveform display and the frequency measurement function

in METER MODE.

Test equipment:

Tektronix TG 501 Time Mark Generator

Test setup:

Procedure/requirements for testing waveform display and frequency function:

Apply a

1 ms

(IV

peak-to-peak) time

marker signal

to channel A. Use a 50Q termtnatbn.

B Check that a stable (triggered) signal is displayed.

C Check that the frequency

displayed

is between 993...1007 Hz.

Page 85

-16

PERFORMANCE

VERIFICATION PROCEDURE

4.3 STANDARD PERFORMANCE VERIFICATION PROCEDURE

SUMMARY

This table provides an overview of all steps

the Standard

Performance Verification Procedure. It Is

intended to be used as a reference for frequent users. For details

how

perform

each Standard

Performance Verification Procedure

step, refer to section 4.2.

SCOPE PART

STEP SIGNAL

SIGNAL SCOPEMETER REQUIRED

SOURCE AMPUFREQ INPUTS

. .

No interrupted lirres

- - •

No interrupted lines

- - -

Traces on mid screen

4 Fluke 51 OOB 212.1

mV(RWS)/1 kHz (sine) A Amplitude: 5.68...6.12dlv.

300 mV/DC A Diet mid

screen end

trace:

2.94...3.06 div.

Fluke

OOB

300mV/0C B Dist mid screen and trace: 2.94...3.06 div.

212.1 mV(RMS)/1 kHz (sine) B Amplitude; 5.

88...6. 12 div.

6 Fluke 5100B 3V/DC

B Dst mid screen and trace: 2.94... 3.06 div.

6V(pp)/1 kHz (sine) B Amplitude: §,63...6.12 div.

7 Fluke 51 OOB 30V/DC

B Dist

mid

screen and trace: 2.94.. .3.06 div.

60V(pp)/1 kHz (sine) B Amplitude: 5.88. 6. 1 2 div.

8 Tek PG 506 0.5V/1 MHz

(fasi rise/square

wa^^e)

B (son term) Rise

time:

<0.7 div.

9 Tek PG 506 0.5V/1 MHz

(fasi rise/sguare

wasre)

A (son term) Rise time: <0.7 div.

Tek

SG 503 120 mV(pp)/50 kHz (sine) A (50n term) Adjust amplitude to 6 div.

11 Tek SG 503 120mV(pp)/5QMHz (atne) A(50n term) Amplftudet > 4.2

div.

Tek

SG 503 120

mV(pp)/50

kHz (sine) B(50n term) Adjust amplitude to 6 div.

13 Tek SG 503 12OmV(pp)/50 MHz (sine)

(50n term) Amplitude: > 4.2 div.

14 Tek SG 503

^500

mV(pp)/1 OO MHz (sine) B

(50n

term) Weil triggered

signal

*100

mV(pp)/60 MHz (Sine) Well triggered signal

IS Tek SG 503 300 mV(pp)/10 MHz (sine)

(^term) Triggered on falling edge

16 Tek SG 503

300 mV(pp)/10 MHz (sine) A (50n

term) Triggered

on falling edge

17 Tek SG 503

*500

mV(pp)/100 MHz (sine) A (5012 term) Well triggered signal

*100

mV(pp)/60

MHz (sine)

Well

triggered

signal

18 Tek TG SOI 1V(pp)/1

fis

(marker) A

(5012

term) Markers

on lines

(tolerance ±

pixel ^±0.04 dtv.)

19 PM 5134 1.2V/1 kHz (Bine)

(pp)

A& EXT

Well triggered

signal

on 1.4V/DC (both son term)

20 PM 5134 800 mV(pp)/2 kHz (sine) A& B

(both son term)

Line with angle

45^

displayed on screen

- •

Trace jumps < 0.1 div. when switching

- •

between setting 21 and 22.

METER PART

STEP SIGNAL SIGNAL

SCDPEMETER 1 REQUIRED

SOURCE AMPL/FftEO

INPUTS

1 Fluke 5100B 300 mV/DC A 298.0...302.0 mV

300mV(RMS)/l kHz 292.5„.307.5 mV

3V/DC 2.960...3.020V

3V(RMSyi kHz

2.925. .3.075V

30V/DC 29.80.. .30.20V

30V(RM5)/1 kHz 29.25,, .30.75V

Fluke 51

OOB 300 mV/DC banana 298.2. .301.8 mV

3V/DC 2982...3.018V

Fluke 51 OOB looa banana 99.00...101.0Q

10M12 9.900...10.10M12

RukeSIOOB 1 kQ banana a420...0.589V

5 TekTG 501 1 V(pp)/1 ms (marker) A (5012 term) Stable oscilloscope picture

Frequency displayed: 993,-1007

Hz.

Page 86

PERFORMANCE VERIFICATION PROCEDURE

4.4 ADDITIONAL PERFORMANCE VERIFICATION PROCEDURE

This paragraph describes the Additional Performance Vehficaton Procedure. This procedure

can

be used to

some extra performance tests, depending on

the

ScopeMeter

version

(93, 95,

or 97).

the instmctions described with each step.

The

recommended test

equipment

required for this Additional

Performance

Verihcation Procedure is

listed

In table 4.4.

Table 4.4 Recommended test equipment for Additional Performance Verification Procedure.

instrument

Type

Recommended Model

Function Generator Philips PM 51 34

Multimeter Philips PM

2525

Power

Supply Philips PE 1537

Time Mark Generator Tektronix TG 501

Constant Amplitude

Sine wave Generator

Tektronix

SG 503

Square wave

Calibration Generator

Tektronix PG 506

•

Cables and

terminators for the generators (all BNC

type)

Two standard banana test leads (delivered with the ScopeMeter)

BNC (fern ale) -to-banana (male) (delivered with the ScopeMeter)

•

5 mm. Power Jack connector plug with attached cable (e.g.; 4822 321 20125)

NOTE: During the following Performance Verificetion Procedure,

you must

connect the ScopeMeter

ir^put connectors to the signal generator outputs. This connection must be made by cables

(BNC connector ctjannei A or B) or two standard banana test leads (COM and

mV/Ohm/Diode banana connectors^ The Additional Performance Verification Procedure

does not use the oscilloscope probes delivered with the Instrument. The calibratior} of the

probes is described in the Operating Manual.

1. Autoset

All

models

•••

This test checks the correct operation of the AUTO SET function.

Test equipment:

Tektronix SQ 503 Constant Amplitude Sine wave Generator

Teat

setup:

ScopeMeter

Page 87

4-18

PERFORMANCE VERIFICATION

PROCEDURE

Settings/procodure/requ

Irements:

A Apply a50MHz $lne wave

signal of 1 00 mV peak-lo-peak

to channel A. Use a 500 termination.

B Switch on the

ScopeMeterand press the SCOPE key to

get into SCOPE mode. Now press me

ALfTO SET key.

Check that the display Is stable and well triggered.

Minimal 2 and maximal 20

signal periods

must be displayed, over 8 divisions.

The signal amplitude must be approximately

divisions.

The NOTRIG indication

the display

must not flash.

C Repeat settings/p rocedure for chan

n el

2. Vertical

dynamic range and position range

(move control)

All models

•••

This test checks

the vertical dynamic range, together with the position

range (move control). A certain

overdrive of

the ScopeMeter must be allowed.

Test

equipment:

Tektronix SG 503 Constant Amplitude Sine wave Generator

Test setup:

ScoMMeier

Settings/procedu

re/requirements for channel A:

Vertical dynamic range

check:

A Switch on the

ScopeMeter and press the SCOPE key to get Into

SCOPE mode.

6 Apply a 50 kHz sine wave signal of

950 mV peak-to-peak to channel A.

Use a 50Q termination.

C Press the AUTO SET key.

Set

channel

speed to lOps/div.

D Use the vertical MOVE

key

to shift

the bottom of the sine wave vertically over the

screen in the

lower division. Shin the top of the sine

wave in the upper division. Verify that the

top and bottom

of the sine wave signal

of 9.5

divisions

can be displayed distortion

free.

E Apply a

50 MHz

sine

wave signal of approximately 500 mV peak-

to- peak

divisions on the

screen) to channel

A. Use a 50Q termination.

F Set the time base

speed to 10 ns/dtv.

G Now a sine wave with an amplitude

of 4 divisions must be displa/ed distortion Iree.

Move control

check:

A Adjust the signal amplitude to 6 divisions on the screen. B Check

that the trace can be moved over 4 divisions

up(+ 4 dI

v.)

and over4 dvisions down (-

4 d

iv. )

Settlngs/procedure/requlrements

for channel 6:

Repeat the total procedure

for

channel

Page 88

PERFORMANCE VERIFICATION PROCEDURE

4-19

Trigger level control range channel A and B

•••

All

models

This test checks the trigger

level control range.

Test equipment:

Tektronix SO SOS Constant

Amplitude Sine

wave

Generator

T^st setup:

Sett

inge/procedure/requ

Iremente

Apply

a 500

kHz sine wave wHh

amplitude o1 950 mV peak-to-peak to channel A. Use a 5012

termination.

B Switch on the ScopeMeter and press the SCOPE key to get into SCOPE mode. Now press the

AUTO SET key.

C Verify that the signal is welt triggered. D Set channel A to 100 mV/div.

E Press the TRIG 3EH key. Use the select/adjust Keys to verify that the trigger level range Is more

than 8 divisions

divisions up and 4 divisions down). The selected trigger level Is shown on the

display {reversed Indication LEVEL*}. Also the trigger level indication, marked with an Aj~

will shift, while shifting the trigger level. See hgure 4.9.

F Repeat the same procedure for channel B.

run

Figure 4.9 Trigger level

indication

on screen

Page 89

4-20

PERFORMANCE VERIFICATION PROCEDURE

4. Power supply voltage range

•**

Ail models

*'•

Th^ test checks the correct operation of the

ScopeMeter within the boundaries of the DC supply

voltage.

Test equipment:

Philips PE 1537 Power Supply 0-40V/0-1A

Tektronix SO 503 Constant Ampittude Sine Wave Generator

5 mm Power Jack connector plug with attached cable {for example order 4622

321 20125)

Test

set-up:

ScoQ«Uetar

Settl ngs/proeedure

A Insert the power

plug into the power adapter contact on the side of the ScopeMeter.

B Switch on the power

supply and set the voltage to a wanted value between 8 and 20V DC.

Apply a 50 kHz

sine

wave v/tth an amplitude of 100 mV peak-to- peak to channel

Use

a SOD

termination.

D Swich on the ScopeMeter. At power on, a beep tone must

audible.

E Press AUTO SET and verify that a well triggered signal with an amplitude of approximately

divisions is displayed over the whole supply voltage range.

Requirements:

A The ScopeMeter must start

at any DC voltage between 3 and 20V, applied at Its power adapter

contact.

B The ScopeMeter must remain operative

over the indicated voltage range.

C The amplitude of the trace displayed

must be approximately 5 divisions, independent of the

supply voltage.

Figure 4.10 Power Jack connector

Page 90

PERFORMANCE VERIFICATION

PROCEDURE

4-21

Supply

current

«•»

All models

This lest checks the total suppl/ current

(ScopeMeter supply curr^ and the bulH-in battery charger current).

Test equipment:

Philips

PE 1537 Power Supply 0-40V/0-1A

Digital Multimeter

(Philips PM 2525 or equivalent)

5 mm Power Jack connector

plug with attached cable (for example order 4822 321 20125).

Test set-up:

PHILIPS PU2S2S

ScopeMeter

Settings/procedure/requirements:

NOTE: A PM

9086

bstl^ry

pack (inctudad in tha shipment) has to be installed for this test

Only NiCad batteries

can be charged b/ the Scr^eMeter!

A Set the power supply

to 1 5V DC.

B Check that

the

charging

current Is 200 mA (typical reading on multimeter).

C Switch on the ScopeMeter.

D Check that the total supply current is 330 mA (typical reading on multimeter).

6. Battery backup functional test

•••

All

models

This test verifies

that the ScopeMeter settings will be kept In memory If power Is switched off while

the batteries

are installed.

Test equipment:

none

Test setup:

no specific test setup required

Settings/procedure:

A Switch on the ScopeMeter and

press the SCOPE key to get into scope mode.

B Press the AUTO SET

key and set channel A and B to 500 mV/div. Set the timebase to

1 ms/div.

C Switch off the ScopeMeter

with the ON/OFF key and keep it switched off for

one hour to enable

all capacitors

to discharge.

Press

the ON/OFF key to switch on the ScopeMeter again,

and verify that the settings for the

timebase and attenuator have not changed.

Requirements:

ScopeMeter settings

at power

off

must be restored the next time power Is switched

on.

Page 91

4-22

PERFORMANCE

VERIFICATION PROCEDURE

7. Cursor measursmsnU:

time accuracy

*•*

Models 95/97 only!

This test checks the

accuracy of the cursors while measuring time.

Test equipment:

Tektronix TG 501 Time Mark Generator

Test setup:

SeoD^Meter

Setting/procedure:

A Apply a 1 ms time marker signal to charnel A. Use a 500 termination.

B Switch on the Scope Meter and press

the SCOPE key to get into SCOPE mode. Now press the

AUTO SET key.

C Set

the

timebase to 1 ms/div.

D Press

the HOLD/RUN key to freeze the display.

E Press

the CURSOR DATA key to get Into the

cursor menu,

F Press the CURSOR softkey to turn on the cursor

lines.

G Position the cursor lines with the

<CURSOR -l-> and <CUfiSOR

2->

keys, so that they cover

distance of 6 time marker Intervals.

Position the markers exactly lothe top of the marker

pulses.

See figure 4.11.

Requirements:

The measured

time distance between the cursors Is displayed

at the right side next to the traces. This

value

must be 5.99... 6.01 ms.

*5VAC PROBE

*10

B OfF PROBE*10

Figure

4. 1 1 Cursor lines on marker pulses

Page 92

PERFORMANCE

VERIFICATfON PROCEDURE 4-23

8. Cursor measurements: vohage

accuracy

•••

Models 95/97 only!

•••

This test checks the accuracy

of the cursors while measuring voltage.

Test equipment:

Tektronix PG 506 Square Wave Calibratfon Generator

Test setup:

Settings/procedure

A Apply

a 1 kHz square wave voltage of IV peak-to-peak to channel A. Use the *STD

AMPL'

output of the PG 506.

B Switch

on the ScopeMeter and press the SCOPE

key to get irio SCOPE mode. Now press

AUTO SET

key.

C Set channel

A to 200 mV/div and to AC coupling.

D Press the HOLD/RUN

key tc freeze the display

E Press

the CURSOR DATA key to get into the cursor

menu.

F Press

the CURSOR softkey to activate

the cursor lines.

G Position the first cursor in the horizontal

middle of the top of the waveform. Use the

<CURSOR

-1->

key to position cursor 1

H Position

the second cursor in the horizontal mid

tiie

bottom of the waveform. Use the

<CURSOR

-2->

key to position cursor2.

Use the most right

softkey to select NORMAL readout.

Requirements:

The measured voltage

between the cursors is displayed

at the

right

side next to the traces. This

value

must

be 0.98V-.. 1.02V.

9. SETUP

memory f unctims

Model 97 only!

***

ScopeMeter

model 97 enables storing up to 10 front settings

that will be kept In a memory with

t>attery backup.

This

test

checks this

function.

Test

equipment;

none

Page 93

4-24

PERFORMANCE VERIFICATION PROCEDURE

Test setup:

no specific set*

required

Setti ng/procedure

A Switch on the ScopeMeter and switch

to SCOPE mode.

Operate the keys to get

from setting

that differs frorr the default settings:

Set channel A and B la

500

mV/di

Set the timebase to 1 ms/div.

B Press the SETUP key to gel into the SETUP

Press the

SAVE softkey, select SETUP 3 from the pop-up menu, and press ENTER. This will

save the current front setting as SETUP 3.

D Set channel A and B lo 2V/div. Set the timebase to

^e/div.

Switch off the ScopeMeter.

F Switch on the ScopeMeter again (do not use MASTER RESET!).

Press the SETUP Key to get

into the SETUP menu.

G Press the RECALL softkey and choose SETUP

from

the pop-up menu. (Use the select/adjust

keys and the ENTER softkey.) This entry

is marked in the pop-up menu. The frortt setting must

be restored to the setting previously selected

In step A.

H Now press the

DELETE softkey. Use the select/adjust key and the ENTER softkey to choose

SETUPS from the pop-up menu. The RECALL marker svill disappear now

as a

sign

that the front

setting is

no longer stored in msmory.

Press the SAVE button to display the SETUP pop-up menu.

Verify that the marker before SETUP

has disappeared.

10. Generator

»»*

Model 97 only!

*»*

This test checks the built-in generator.

Test equipment:

none

Test setup:

ScopeMMr

Page 94

PERFORMANCE

VERIFICATION

PROCEDURE 4-25

S«ttlngs^^roeedura/raq uirofnorto

Squsr0 wave

A Switch on the ScopeMeter and

press the SCOPE key to get Into scope

mode.

B Press We SPECIAL FUNCT

Key. Now press the left most softkey, marked

GENERATE. This will

reveal the GENERATE

pop- up menu.

C Use the select/adjust

keys to select “Square: 976 Hz" and press

the right most ENTER softkey

to activate the generator.

0 Press the LCD key, and then

press the softkey PROBE CAL. This will

reveal the CAL&ADJUST

pop-up menu. Use the select^adjust

keys to select "Channel A 1 ;1 and press

the ENTER softkey

to activate 1:1 coupling.

E Now

press AUTO SET.

F Press

the CURSOR DATA key. This will

get you to the CURSOR DATAmenu.

Press

the CURSOR softkey. Use the

<-CURSOR

1->

key to position the left

cursor line on the

most negative part of the square

wave signal. Use the <-CURSOR

2->

key to position the right

cursor line on the top of the square

wave sgnal.

H Now press the FUNCTION softkey. This will reveal

the FUNCTION pop-up menu. Use the

select/adjust keys to select "FREQUENCY"

and press the ENTER

softkey to activate the

frequency

measurement. Press the

FUNCTION softkey again. This will remove

the FUNCTION

pop-up menu.

1 The

ScopeMeter display will look like figure

4.12. The generator must produce

square

wave

signal with

amplitude

of 5V and a frequency

of 976 Hz (tyfrical values).

A2VAC

B2VOFF PROS

10:1

MOms/DIV

TRIG: at

—

1 »

1 1 t

1 1 n

dV: 5,00

•

B IB 11

2.64

B 1 B

•REQ

976

1 1

11B

FUNCTION MARK or A

NONE

Figure

4. 12 Generator produces square

wave

signal

S/ne wave

J Now press the SPECIAL

FUNCT key. Press We GENERATE

softkey to reveal the GENERATE

pop-up menu. Use the

select/adjust keys to select "SINEWAVE"

and press the ENTER softkey

activate

the generator.

Use the mV/V keys to adjust the attenuator.

Page 95

4-26

PERFORMANCE VERIFICATION PROCEDURE

L The ScopeMeter display will

look like figure 4.1 3. The generator

must produce a sine wave

signal with an

amplitude of IV and a frequency of 976 Hz (typical values).

A200mVAC

8 2V OFF PROBE 10:1

CSV;

1.CO

dt:

2.64

FREQ:

97S

START

9ni79

Figure 4. t3 Generafor produces sine wave signal

500ya/DIV

TRIG.

GENERATE MEASURE PRINT PRINTER

^ ^

FORMAT^ SETUPS

11.

Component test function

»**

Model 97 only!

*»•

This test checks the component test function (slow ramp

voltage and slow ramp current).

Test equipment:

Red

scope probe (delivered with the ScopeMeter)

Test setup:

aius

Settinga/procedure/requiremente;

A Switch on the ScopeMeter

and press the SPECIAL FUNCT key to enter the SPECIAL

FUNCT

menu.

B Now press the MEASUREsoftkey. This

will reveal the MEASURE pop-up menu.

Page 96

PERFORMANCE

VERIFICATION PROCEDURE

4-27

C Use the selecVadjusl

keys to select "Components:

VOLTAGE', and press the ENTER softkey

(most

right) to start the component test function.

D Adjust the channel A

attenuator (press the mVA/ key

once In the direction "mV") to set the

vertlcai axis

to 500 mV/div.

E The ScopeMeter

display will now look like figure

4,14.

you use a 10 kQ resistor, a

45^

line will

be shown.

F Press the

MEASURE softkey and

use the select/adjust keys to select "Components:

CURRENT"

from the MEASURE pop-up

menu. Activate the selection by pressing the ENTER

softkey.

G Exchange the

10 kO resistor for a 1 kO resistor.

H Now the ScopeMeter display

will show a line under

45'’,

in the

upper left quadrant.

-2V -W OV +1V

+2V

Figure 4. 14 Componer^i

test "VOLTAGE'' mode

Page 97

CALIBRATION ADJUSTMENT PROCEDURE

5-1

CALIBRATION ADJUSTMENT PROCEDURE

5.1 GENERAL INFORMATION

The following information provides the complete Calibration Adjustment Procedure for the

ScopeMeter. Because various control functions are interdependent, a certain

order of adjustment is

necessary. The procedure is

therefore

presented in a sequence

that

is best

suited

this order.

Before

you

make calibration adjustments, always

use the

Performance Verification Procedure in

chapter

4 to

check the ScopeMeter performance.

The Calibration Adjustment Procedure, described here, consists of the following three parts:

•

CONTRAST

Calibration Adjustment

Procedure

•

SCOPE

Calibration Adjustment Procedure

•

METER

Calibration

Adjustment Procedure

Almost all Calibration Adjustments can

done without opening toe instrument. Only the first four

steps of the SCOPE Calibration Adjustment Procedure require disassembling of the ScopeMeter

(see section 5.6.1).

NOTE: Every year use the Performance Verification Procedure in chapter 4 to check the

ScopeMeter. tfthe ScopeMeter fails the Periormarrce Verification Procedure, Caf/Prafton

Adjustments

must be made, if the

ScopeMeter also fails the Calibration Adjustment

Procedure,

repair is necessary (see

chapter

7).

(After repair,

is sometimes also necessary

to do also

Hardware Calibration Adjustment,

see

section

5.6.1)

Sections 5.5, 5.6 and 5.7 describe the calibration process in detail. Section 5.8 contains a summary

of all calibration adjustments as a reference for more frequent users.

5.2 RECOMMENDED CALIBRATION ADJUSTMENT EQUIPMENT

The equipment recommended for the Calibration Adjustment Procedure is listed in table 5.1.

All calibration adjustments must be done in ambient temperatures between 18C and 28C. The

ScopeMeter can be used immediately: there is no warm-up time specified.

Table 5. 1 Recommendedcalibration adjustment equipment survey

Instrument Type Recommended Model

Multifunction Calibrator Fluke 51 OOB

Square Wave Calibration Generator Tektronix PG 506

Function Generator Philips PM 5134

Personal Computer Any IBM compatible PC, running MS-DOS

*) Optical to

RS-232 Interface Cable PM9080/001

*) Flash ROM Refresh software

Contact your Service Center

*) +12V

(±

2.5%) Programming voltage

)

These items are required after three calibrations,

see

note paragraph

5.3, pag

5.3 for details.

Page 98

5-2

CALIBRATION

ADJUSTMENT PROCEDURE

Cables and terminators for

the generators {all 6NC t^e]

•

Standard banana test leads

(two banana lest leads are delivered

wltti the ScopeMeter)

•

BNC (female)-lo-banana (mate) (delivered

with the ScopeMeter)

•

The red and grey probes,

delivered with the ScopeMeter.

5.3 ENTERING

THE CAUBRATION

PROCEDURE

The Calibration Adjustment Procedure Is operated

via built-in sequences. Before you can activate

calibration

sequence, you must first connect a 1 2V DC programming

vohage to the ScopeMeter. To

do this, Rrst

remove the bettery pack. See section 6.2.1.

Figure 5. 1 Position

of the

-t‘12V

and 0 contacts for calibration (items

25)

If you have removed the ScopeMeter battery

pack and the battery cover (figure 5.1

item

17), you

will

have access to the -»-12V/0 contacts (figure

5.1

item

25). These contacts are placed in the left middle

(+12V) and the right middle

(0)

of the

battery

compartment. Connect +12V DC to the cor^tact marked

•+1

2V" and OV to the contact marked

“0".

CAUTION:

To avoid damaging the Flash ROM circuitry be sure

to apply the polarity of 1 2V

programming voltage correctly.

NOTE: After

you have performed the Calibration Procedure, remove

the 12V

programming

voltage.

Do not perform measurements with the ScopeMeter, while

the programming voltage is stiH

present

Page 99

CALIBRATION

ADJUSTMENT PROCEDURE 5-3

Connect the

Charger PM 8907. Use MASTER RESET

switch

the ScopeMeter on. {To do this press the LCD

key and keep rt pressed. Then also press the

ON/OFF key. When

the ScopeMeter switches on, you wili

hear two beeps.) Now press both

AC/DC/GROUND

keys simultaneous^. This will start

the SERVICE menu (see figure 4.1

chapter

4),

This menu allows

you to start the calibration

sequence. Press the corresponding softkey marked

"CALIBRATE

ScopeMeter". This will

start

the

CALIBRATE menu.

NOTE:

The ScopeMeter will show the message:

"Space for X more calibration sessions.

“(X

is:

2. 1.or0}

After three electronic calibrations,

the ScopeMeter will display:

"Space for 0 more calibration

sessions". This means

that the internal Flash ROMs of the ScopeMeter

are full. To enable another

calibration, you must first empty

the Flash ROMs and reinstall

the ScopeMeter ope rati rtg software.

To do this, send

the ScopeMeter to your nearest Service Center.

also possible to 'refresh* the

FlashROMs

yourself,

using a PC. For more

Informatlort: contact your nearest Service

Center.

5.4

OPERATING THE CALIBRATION

PROCEDURE

Softkeys

in the CAUBRATE menu

In the CALIBRATE menu,

is possible

to choose the calibration mode (sequence)

to be performed.

Press the softkey marked:

•

CONTRAST for the CONTRAST

Cdilbratlon Adjustment Procedure

(see

section

5,5).

•

SCOPE for the

SCOPE

Calibration

Adjustment Procedure

(see section 5.6).

•

METER for the METER

Calibration Adjustment Procedure

(see section 5,7).

When

one of ^ese three calibration

sequences is chosen, the corresponding text

on ^e

screen

will

be shown in reverse. This shows that

this calibration mode is active.

If you press

the ESCAPE softkey, the ScopeMeter will leave

the CALIBRATE menu and return

to the

SERVICE menu.

NOTE: If

you use the ESCAPEsoftkey

to leave the CAU8RATION menu before

storing the

calibrations with the CAL

STORE softkey you will lose all new calibration

values. The

instrument

will continue using

the calibration values that were

used

before

entering the

CAUBRATE menu.

The CAL STORE

softkey saves the new calibration values

that are obtained in the

CONTRAST

SCOPE Of METER sequences,

to the Flash ROM. From the

moment you press the CAL STORE

softkey, the ScopeMeter

uses the new caftbration data. The old

calibration data is no longer valid.

This will also fill one calibration

field in the Flash ROM.

See secticn 5.3.

NOTE: After calibrating

the ScopeMeter, reset

the instrument (use a MASTER RESET),

before

performing measurements.

Keys In CONTRAST,

SCOPEs orMETER Caiibraiion

mode

The calibration is presented

as a sequence. You

can

advance

through this sequence

pressing

the

select/adjust keys. Pressing the

upper select/adjust

key

advances

one step; pressing the tower

adjueVselect key brings

you back

one

step.

sections 5.5, 5.6 and S.7 this figure

is used to indicate that one of the

select/adjust keys (up/down)

must be pressed to display the indicated

step

number V displayed on the

ScopeMeter screen.

Page 100

5-4

CAUBRATION ADJUSTMENT PROCEDURE

When the ScopeMeter LCD displays the indication CAL", you must first apply the appropriata input

(calibration) signal. When the correct signal is present at the correct terminal, you start the built-in

calibration by pressing the most right READY softkey. The text “READY" will be in reverse video, to

show that the ScopeMeter’s internal calibration is active. When the process is ready, the "READY"

text will change again, from inverted to normal. Now you can use the select/adjust

Keys to advance

to the next calibration step or return to

previous calibration

step.

After you have completed a calibration sequence, press either CONTRAST.

SCOPE

or METER

softkey again to return to the CALIBRATE menu. The new calibration data will stay in memory to

enable you to store it permanently with the CAL STORE key.

Press the ESCAPE softkey to leave the active calibration mode without storing the new calibration

data.

This

will

also

return you to the CALIBRATE menu.

5.5 CONTRAST

CAUBRATION ADJUSTMENT PROCEDURE

You activate the CONTRAST Calibration Adjustment Procedure from the CALIBRATE menu, by

pressing

the left most CONTRAST softkey. When this softkey Is depressed, the text ‘CONTRAST" is

shown in

reverse video,

to show that this calibration mode is

active.

Now

use

the adjusl/select

Keys

to adjust

the

contrast

of the

LCD

your own (personal)

setting.

When

you

have found the correct setting,

you can

make this setting ready for calibration atorage,

pressing

frie READY

softkey

once.

NOTE: When you press the READY softkey, this does not mean that the new value of the LCD

oc»/?frast/s actually stored in the Flash ROMs of the ScopeMeter. This only happens when

you

press

the CAL STORE softkey.

Press the CONTRAST softkey again to ieave the CONTRAST Calibration Adjustment Procedure.

The text "CONTRAST will change from reverse video Into normal again.

5.6 SCOPE CALIBRATION ADJUSTMENT PROCEDURE

You can start the SCOPE Calibration Adjustment Procedure from the CALIBRATE menu by pressing

the SCOPE softkey. When this softkey is pressed, the text 'SCOPE" is shown in reverse video, to

show that this calibration mode is active.

The SCOPE Calibration Adjustment Procedure Is divided into two parts:

Hardware SCOPE Caiibration Adjustments: steps H1 to H4

•

Closed Case SCOPE Calibration Adjustments steps 85 to S29

NOTE: During the following CaliPration Adjustment Procedure,you must connect the ScopeMeter

input connectors to the signal generator outputs by means of cables (BNC connectorchannel

A or B) or two standard banana test leads (COMand mV/Ohm/Dk>de banana connectors).

5.6.1 Hardware SCOPE Calibration Adjustments

The first four

steps

of the SCOPE Ceilbration Adjustment Procedure are called Hardware SCOPE

Calibration Adjustments. To perform the Hardware SCOPE Calibration Adjustments, you must

open the ScopeMeter. The dissssembly procedure for these calibration adjustments is described in

chapter

(section 6.1 and 6.2.3).