FLUKE 45 Dual Display Multimeter. Service Manual (For IEC 1010 Meters Only)

List of Replaceable Parts

Introduction

6-1.

Introduction

This chapter contains an illustrated list of replaceable parts for the Fluke 45 Dual

Display Multimeter. Parts are listed by assembly; alphabetized by reference designator.

Each assembly is accompanied by an illustration showing the location of each part and

its reference designator. The parts lists give the following information:

• Reference designator

• An indication if the part is subject to damage by static discharge

• Description

• Fluke stock number

• Total quantity

• Any special notes (i.e., factory-selected part)

Caution

A * symbol indicates a device that may be damaged by static

discharge.

6-2.

How to Obtain Parts

Electrical components may be ordered directly from the manufacturer by using the

manufacturers part number, or from the Fluke Corporation and its authorized

representatives by using the part number under the heading FLUKE STOCK NO.

Parts price information is available from the Fluke Corporation or its representatives.

Prices are also available in a Fluke Replacement Parts Catalog which is available on

request.

In the event that the part ordered has been replaced by a new or improved part, the

replacement will be accompanied by an explanatory note and installation instructions, if

necessary.

To ensure prompt delivery of the correct part, include the following information when

you place an order:

• Instrument model and serial number

• Part number and revision level of the pca containing the part.

• Reference designator

• Fluke stock number

• Description (as given under the DESCRIPTION heading)

• Quantity

6-3

Service Manual

6-3. How to Contact Fluke

To contact Fluke, visit Fluke’s web site at www.fluke.com or call one of the following

telephone numbers:

USA and Canada: 1-888-99-FLUKE (1-888-993-5853)

Europe: +31 402-675-200

Japan: +81-3-3434-0181

Singapore: +65-738-5655

Anywhere in the world: +1-425-446-5500

6-4. Manual Status Information

The Manual Status Information in Table 6-1 defines the assembly revision levels that are

documented in the manual. Revision levels are printed on the component side of each

PCA.

Table 6-1. Manual Status Information

Ref or

Assembly Name

Fluke Part No.

PCA Revision Levels

Option

No.

Main PCA

814137

A1A1

True Rms PCA

848200

Display PCA

609179

-01

Battery PCA

825885

-05

IEEE-488 Interface PCA

814152

6-5. Newer Instruments

Changes and improvements made to the instrument are identified by incrementing the

revision letter marked on the affected pca. These changes are documented on a manual

supplement which, when applicable, is included with the manual.

6-6. Parts

The following pages give detailed listings of Fluke 45 parts.

Note

This instrument may contain a Nickel-Cadmium battery. Do not mix with

the solid waste stream. Spent batteries should be disposed of by a qualified

recycler or hazardous materials handler. Contact your authorized Fluke

service center for recycling information.

6-4

List of Replaceable Parts

Parts

Table 6-2. Final Assembly

Reference

Description

Fluke

Total

Note

Designator

Stock

Qty

No.

MAIN PCA

814137

DISPLAY PCA

609179

FUSE,5X20MM, .500A, 250V, FAST

838151

FUSE,.406X1.5,FAST,11A,1000V,FAST

943118

3, 4

FUSE,5X20MM,0.125A,250V,SLOW

822254

FUSE,0.44 A, 1000V, FAST

943121

1, 2

CONN ACC,D-SUB,FEMALE SCREWLOCK,.250

844704

NUT,EXT LOCK,STL,6-32,.344OD

152819

4-7, 14

SCREW,FHU,P,LOCK,SS,6-32,.250

320093

SCREW,PH,P,LOCK,STL,6-32,.250

152140

SCREW,PH,P,THD CUT,STL,4-14,.500

853668

10, 11

SCREW,TH,P,SS,4-40,.187

721118

12, 13

SCREW,PH,P,LOCK,MAG SS,6-32,.500

853986

15, 16

SCREW,FH,P,LOCK,STL,8-32,.375

114116

PWR PLUG,PANEL,6.3A,250V,3 WIRE

780817

PWR PLUG PART,FUSE HOLDER

780825

PAD TRANSFER,FRONT PANEL (CE)

609427

PAD TRANSFER, WINDOW

835496

ASSEMBLY, CHASSIS

784793

GROMMET,EXTRUDED,POLYETHYLENE,.085

854351

DECAL,REAR PANEL (CE)

609419

INSULATOR, TRANSFORMER

852413

SPACER,SNAP,.180 RND,NYL,.125

844845

STANDOFF, FEMALE

874748

RECEPTACLE,FUSE

824607

ROD,POWER SWITCH

784827

SHIELD,TOP

784819

SHIELD,BOTTOM

791590

CASE,OUTER

784769

14, 15

CASE,FOOT, BLACK

824433

BEZEL, REAR

885889

MOUNTING PLATE,HANDLE(LEFT)

857248

MOUNTING PLATE,HANDLE(RIGHT)

857243

HANDLE,PAINTED

848205

COVER,IEEE

791616

CALIBRATION SEAL

735274

TEST LEAD ASSY, TL70A

855820

LABEL,ADHES,PAPER,,4.750,3.1875

854104

STANDOFF, MALE

874743

SCREW, PH, 4-14 312

642931

SWITCH,PUSHBUTTON,DPDT,PUSH-PUSH

836361

KEYPAD,ELASTOMERIC

855994

TRANSF,PWR,35W,90-264VAC,14.6-43VAC

609088

FLUKE 45 USER MAN, ENGLISH

855981

FLUKE 45 USER MAN, GERMAN/FRENCH

856034

CABLE ASSY,RS232

848192

WIRE ASSY,GROUND

834952

CABLE ASSY,FLAT,20 COND,MICROMOD,3 IN

831578

CORD,LINE,5-15/IEC,3-18AWG,SVT,7.5 FT

284174

1. For 250 V order part number 769422.

6-5

Service Manual

Table 6-3. A1 Main PCA

Reference

Fluke

Description

Tota

Note

Designator

Stock

l Qty

No.

TRUE RMS PCA

848200

I C,OP AMP,JFET INPUT,DECOMP,SOIC

837237

CAP,POLYES,0.1UF,+-10%,1000V

837518

CAP,CER,4.7PF,+-0.25pF,50V,C0G,1206

644978

3, 5, 9, 19,

CAP,CER,0.1UF,+-10%,25V,X7R,1206

747287

22-25, 49,

17, 18

CAP,CER,4.3PF,+-10%,50V,C0G,1206

844738

6, 42-44

CAP,AL,470UF,+-20%,10V,SOLV PROOF

822387

7, 10

CAP,POLYES,0.47UF,+-10%,50V

697409

CAP, 2.2µF

697433

12, 13

CAP,POLYPR,0.12UF,+-10%,50V

851738

14, 16

CAP,POLYPR,0.033UF,+-10%,63V

721050

CAP,TA,2.2UF,+-10%,35V

697433

20, 21

CAP,CER,15PF,+-10%,50V,C0G,1206

837393

26, 37- 40

CAP,CER,0.047UF,+-20%,50V,X7R,1206

782615

CAP,AL,4700UF,+-20%,35V,SOLV PROOF

821553

CAP,CER,33PF,+-10%,50V,C0G,1206

769240

29, 30

CAP,CER,1800PF,+-10%,50V,C0G,1206

769786

CAP,CER,0.047UF,+-10%,100V,X7R

844733

32, 36, 47

CAP,AL,10UF,+-20%,63V,SOLV PROOF

816843

CAP,AL,220UF,+-20%,50V,SOLV PROOF

831867

34, 35,41,

CAP,AL,47UF,+-20%,50V,SOLV PROOF

822403

CAP,AL,2.2UF,+-20%,50V,SOLV PROOF

769687

CAP,CER,100PF,+-10%,50V,C0G,1206

740571

CAP,CER,10PF,+-10%,50V,C0G,1206

747311

DIODE,SI,BV=70.0V,IO=50MA,DUAL,SOT23

742320

DIODE,SI,100 PIV,1.0 AMP

698555

5, 10-12

DIODE,SI,BV=75V,IO=250MA,SOT23

830489

DIODE,SI,SCHOTTKY BARRIER,40V,1A

837732

DIODE,SI,DUAL,BV=50V,IO=100MA,SOT23

851659

DIODE,SI,BV=100,IO=100MA,DUAL,SOT23

821116

HEADER,1 ROW,.050CTR,20 PIN

831529

HEADER,1 ROW,.050CTR,14 PIN

831511

HEADER,1 ROW,.100CTR,4 PIN

631184

HEADER,1 ROW,.050CTR,10 PIN

831503

HEADER,1 ROW,.100CTR,3 PIN

845334

1- 3

RELAY,ARMATURE,2 FORM C,5VDC,LATCH

603001

CONTACT,FUSE 15AMP

844287

SPRING,COIL,COMP,SS,.750,.240

836411

SOCKET,IC,28 PIN,DUAL WIPE,BEAM TYPE

756353

CONTACT, FUSE

659524

CONTACT, FUSE

844287

6-8

List of Replaceable Parts

Parts

Table 6-3. A1 Main PCA (cont)

Reference

Fluke

Description

Total

Note

Designator

Stock

Qty

No.

TRANSISTOR,SI,NPN,SELECT IEBO,SOT-23

821637

2- 8

TRANSISTOR,SI,N-JFET,SOT-23

820860

TRANSISTOR,SI,NPN,SMALL SIGNAL,SOT-23

742676

10, 12

TRANSISTOR,SI,PNP,T092

698290

11, 13

TRANSISTOR,SI,NPN,SELECTED IEBO,TO-92

685404

RES,WW,10,+-5%,5W,30PPM

822064

RES,WW,.010,+-5%,1W,100PPM

820845

4, 19, 22

RES,CERM,200K,+-5%,.125W,200PPM,1206

746743

RES,WW,3.5k,+-5%,5W,20 PPM

107695

RES,CERM,100K,+-5%,3W

820811

8, 16, 17

RES,CERM,22,+-5%,.125W,200PPM,1206

746230

9,37,38, 59

RES,CERM,10K,+-5%,.125W,200PPM,1206

746610

RES,CERM,100K,+-5%,.125W,200PPM,1206

740548

11-15,

RES,CERM,47K,+-5%,.125W,200PPM,1206

746685

31,39,45,

55, 56

RES,CERM,1M,+-5%,.125W,200PPM,1206

746826

20, 27, 29

RES,CERM,200,+-5%,.125W,200PPM,1206

746339

RES,CERM,215K,+-1%,.125W,100PPM,1206

836643

RES,CERM,61.9K,+-1%,.125W,100PPM,1206

821330

RES,CERM,16.9K,+-1%,.125W,100PPM,1206

836635

RES,CERM,13.3K,+-1%,.125W,100PPM,1206

836619

RES,CERM,845,+-1%,.125W,100PPM,1206

821322

28,32

RES.CHI,CERMET, 1K, ±5%, 1/8W

745992

RES,CF,20K,+-5%, 0.25W

441477

RES,CERM,180,+-5%,.125W,200PPM,1206

746321

RES,CF,220K,+-5%,0.25W

851837

RES,CF,1M,+-5%,0.25W

649970

RES,CERM,470K,+-5%,.125W,200PPM,1206

746792

RES,CERM,10.5K,+-1%,.125W,100PPM,1206

851852

RES,CERM,68.1K,+-1%,.125W,100PPM,1206

851845

RES,CF,10K,+-5%,0.25W

697102

RES,CERM,5.62K,+-1%,.125W,100PPM,1206

837047

46- 49

RES,CF,0.50,+-5%,0.25W

830646

50, 53

RES,CERM,432,+-1%,.125W,100PPM,1206

811885

51, 52

RES,CERM,47,+-5%,.125W,200PPM,1206

746263

54,60

RES, MOX 22M,+-5%,1W, 200 PPM

688887

RES,CERM,910,+-5%,.125W,200PPM,1206

769257

RES,CF,1K,+-5%,0.25W

780585

THERMISTOR,DISC,POS,1.1K,+-20%,25 C

602995

1, 2, 3

VARISTOR,910V,+-10%,1.0 MA

876193

6-9

Service Manual

Table 6-3. A1 Main PCA (cont)

Reference

Fluke

Designator

Description

Total

Note

Stock

Qty

No.

INDUCTOR,FXD,DUAL,EE24-25,0.4MH,1.2A

817379

TRANSF,INV,5VDC,30KHZ,6KV ISO,EE375

817395

MERCURY/SATURN, ASSY TESTED PLASTIC

776195

IC,ARRAY,7 NPN DARLINGTON PAIRS,SOIC

821009

ISOLATOR, OPTO, LED, TRANSISTOR

688314

IC,NMOS,64 X 16 BIT EEPROM

822353

IC,CMOS,8-BIT MPU,1 MHZ,256 RAM,PLCC

821298

IC,CMOS,RS232 DRIVER/RECEIVER,SOIC

821538

EPROM, PROGRAMMED 27C512

857797

IC,CMOS,AND-NOR GATES,SOIC

837203

IC,CMOS,8K X 8 STATIC RAM,120NS,SOIC

851795

IC,VOLT REG,ADJ,SWITCHING REGULATOR

821215

IC MICROPROCESSOR RESET CIRCUIT

602920

ZENER,TESTED

857201

ZENER,UNCOMP,6.0V,5%,20MA,0.2W,SOT-

837161

837179

ZENER,UNCOMP,5.1V,5%,20MA,0.2W,SOT-

834929

834945

WIRE ASSY,(H)

834911

WIRE ASSY,FUSE

834937

WIRE ASSY,INPUT (10A CUR)

650390

WIRE ASSY,(L)

570606

CRYSTAL,3.84MHZ,+-0.05%,HC-18/U

851100

CRYSTAL,3.6864MHZ,+-0.005%,HC-18U

847363

RES NET THN F TESTED

833921

RES NET THK FILM TESTED

849984

RES NET THN FILM TESTED

RES NET THK FILM TESTED

1. Fusible resistor. To ensure safety, use exact replacement only.

6-10

List of Replaceable Parts

Parts

Table 6-5. A2 Display PCA

Reference

Fluke

Description

Total

Note

Designator

Stock

Qty

No.

CAP,CER,0.1UF,+-10%,25V,X7R,1206

747287

CAP,TA,4.7UF,+-10%,20V

605433

DIODE,SI,BV=75V,IO=250MA,SOT23

830489

TUBE,DISPLAY,VAC FLUOR,7&8-SEG,10CHAR

783530

HEADER,1 ROW,.050CTR,20 PIN

831529

AF TRANSD,PIEZO,22 MM

602490

MP 1

FLUKE 45-3021, PWB DISPLAY

609161

TRANSISTOR, SI, PNP, 40V, 300 mW, SOT 23

742684

1, 10, 12

RES,CERM,10K,+-5%,.125W,200PPM,1206

746610

2, 5

RES,CERM,2.2M,+-5%,.125W,200PPM,1206

811778

RES,CERM,1.2M,+-5%,.125W,200PPM,1206

806240

RES, CERM,47K,±5%, .125W,220 PPM,1206

746685

IC,CMOS,4-BIT MPU,D75212GF,SMR

688879

RESONATOR, SMR, CERM, 4.19 MHz

688317

IC,CMOS,DUAL MONOSTB MULTIVBRTR,SOIC

806620

IC,CMOS,QUAD 2 IN NAND W/SCHMT,SOIC

837245

RES,CERM,SOIC,16 PIN,15 RES,10K,+-5%

836296

6-13

Chapter 7

Option -01 Battery Pack

Title

Page

7-1.

Introduction

7-3

7-2.

Specifications

7-3

7-3.

Theory of Operation

7-3

7-4.

Functional Block Description

7-3

7-5.

Switching Power Supply

7-5

7-6.

Cycle/Float Charge Rate Switch

7-5

7-7.

Low Battery Indicator Detector

7-5

7-8.

Low Battery Disconnect

7-5

7-9.

Constant Voltage Trickle Charger

7-6

7-10.

Other Circuits

7-6

7-11. General Maintenance

7-6

7-12.

Removal

7-6

7-13.

Installation

7-7

7-14. Performance Testing

7-9

7-15.

General Operability

7-9

7-16.

Low Battery Indicator Detector and Low Battery Disconnect Test. 7-10

7-17.

Cycle/Float Charge Rate Switch Test

7-10

7-18. Calibration

7-12

7-19. Troubleshooting

7-13

7-20. Additional Tests

7-14

7-21. Schematic Diagram

7-14

7-22. List of Replaceable Parts

7-14

7-1

Option -01 Battery Pack

Introduction

7-1.

Introduction

The Fluke 45-01K Battery Kit is a field installable option that may be installed in the

meter. The installation of the Battery Kit facilitates portable operation of the meter for

typically eight hours.

7-2.

Specifications

Specifications for the Battery Kit Option are as follows:

• Type of Cell: Sealed Lead-Acid Rechargeable

• Battery Voltage: 8 Volts Nominal

• Charge Time: 16 Hours Typical w/meter off

7-3.

Theory of Operation

7-4.

Functional Block Description

The Battery Pack Option PCA consists of the five functional blocks illustrated in Figure

7-1. Each block is described below:

• Switching Power Supply

The Switching Power Supply regulates the 7.5 V-to-35 V raw dc input provided by

the main circuit board (J1-7). The supply output (9.3 V to 9.8 V, temperature-

compensated) is used to charge the 8 V lead-acid battery.

• Cycle/Float Charge Rate Switch

The Cycle/Float Charge Rate Switch monitors the charging current required by the

battery pack and sets the output voltage accordingly (9.35 V for trickle charging, or

9.8 V for cyclic charging).

• Low Battery Indicator Detector

The Low Battery Indicator Detector monitors the battery pack voltage, outputting a

logic low to turn on the meter low voltage indicator when the battery pack voltage is

below approximately 7.7 V.

• Low Battery Disconnect

The Low Battery Disconnect circuit interrupts meter loading on the battery pack

when battery pack voltage drops below approximately 7.0 V. This action prevents

deep discharge of the batteries.

• Constant Voltage Trickle Charger.

When the meter is operated on line power, the charge on the battery pack is

maintained with the Constant Voltage Trickle Charger (9.25 V output).

7-3

Option -01 Battery Pack

Theory of Operation

7-5.

Switching Power Supply

The switching power supply regulates the output voltage with a pulse-width modulating

technique that varies the on time of the FET switch, Q5. The controller chip for this

process (U4) contains the required 1 V reference, switching oscillator, regulator

comparator, current limit comparators, and output switch. The controller chip is

supported by several external components: C7 sets the oscillator frequency; R17, C6,

and C8 are required for stability; R15, R21, and R20 set the output voltage level. The

variable-width pulse from U4-5 is first level-shifted and clamped by R23, R24, and CR7

and then coupled to the FET switch circuit through inverter U3-2. Hex inverters U3-4,

U3-6, and U3-10 are connected in parallel to provide sufficient drive to the FET gate.

FET switch Q5 is turned on at the beginning of each square wave drive cycle and turned

off at the point necessary to set the desired output voltage.

The current limit is set by the voltage drop across the 0.1-ohm resistance provided by the

parallel configuration of five 0.5-ohm resistors (R29, R34, R35, R36, and R37). Current

limiting occurs when the voltage drop across the ohm resistance is greater than

approximately 100 mV. Current limiting is effected by reducing the duty cycle of the

switching transistor, Q5, which in turn reduces the output voltage of the supply.

A bootstrap supply for the driver and coupling/clamp circuits is provided by CR8, R25,

C9, C11, VR3. The output level has a negative temperature coefficient to provide the

proper charging voltage level for the battery pack over a broad temperature range. This

negative coefficient is provided by the Temperature Compensation circuit (Q4, R18, and

R19) in the feedback path of the switching power supply.

7-6.

Cycle/Float Charge Rate Switch

The Cycle/Float Charge Rate Switch monitors the charging current supplied to the

battery pack during charge when the meter is de-energized. If the current is 60 mA to 80

mA or higher, the charging voltage is increased to about 9.8 V. This level of current

causes a voltage drop across R28 that is sufficient to turn Q6 and Q7 on, connecting one

end of R22 to common. The resulting current through R22 modifies feedback to the

switching supply, causing the increased output voltage.

As the battery pack charge reaches about 90% of capacity, the charge current at 9.8 volts

drops below 60 to 80 mA; Q6 and Q7 turn off, and the charging voltage decreases to

9.35 volts, the trickle charge level for the battery pack. Diode CR10 clamps the voltage

across R28 to about 0.8 V maximum.

7-7.

Low Battery Indicator Detector

The Low Battery Indicator Detector uses comparator U2-7. Bandgap reference VR2 is

connected to the inverting input of the comparator, while the divided-down battery

voltage is connected to the noninverting input. Resistor R16 provides the comparator

with a hysteresis of approximately 0.25 V.

The comparator output is an open collector transistor connected to pull-up resistor R45

on the Main Circuit Assembly. When the battery pack voltage falls below about 7.7 V,

U2-7 goes low. When the battery pack voltage rises above about 8.0 volts, U2-7 goes

high. If the battery pack option is not installed, the pull-up resistor on the Main Circuit

Assembly pulls the battery line high to keep the low battery indicator turned off.

7-8.

Low Battery Disconnect

The Low Battery Disconnect uses FET switch Q2. The FET gate is driven by a latching

circuit comprised of Q3, Q12, Q13, and VR4.

7-5

Service Manual

When the power switch is first turned on, a pulse through C15 turns on Q13, which then

turns on Q3. With the Q3 collector voltage now near its emitter voltage and the FET gate

near the battery voltage, the FET switch is on. At the same time, Q12 is turned on; its

collector pulls down the base of Q3, latching the circuit on.

When the voltage between the base of Q12 and the anode of VR4 drops below 6.9 volts

(battery voltage of about 7.0 volts), Q12 cannot be maintained on due to the 6.2 V zener

diode in its emitter circuit, and the circuit unlatches itself. The gate of Q3 then goes to

zero and turns off, disconnecting the battery pack. If the battery pack charge is low, this

circuit does not latch, and the battery pack is protected from being deeply discharged.

7-9.

Constant Voltage Trickle Charger

The Constant Voltage Trickle Charger uses a voltage regulator set at 9.25 volts. The

output voltage is set by the values of R38, R40, and the setting of R39. The 30-volt

supply on the Main Circuit Assembly provides the source for the regulator. Trickle

charging occurs only when the meter is operated on line power.

If trickle charging occurs when the battery pack is low, R2 limits charging current to

about 15 mA maximum.

When the meter is operated solely on battery pack power, the charger is disconnected

from the battery pack. A logic level signal (ACON*) from the Main Circuit Assembly

(J1-5) is maintained high, and the output of comparator U2-1 goes low, pulling U1-1 to

common and setting the U1-2 output at 1.25 volts. CR4 is thus reversed biased,

disconnecting the charger from the battery pack.

7-10.

Other Circuits

During the various modes of operation, switching diodes provide the required battery

pack connections. During battery pack operation of the meter, CR3 connects the battery

pack to the switching supply on the Main Circuit Assembly. During charging (line power

connected), CR5 connects the battery pack to the charging circuit. If line power is

disconnected, CR9 disconnects the battery pack from the charging circuit.

The 5-amp battery pack fuse opens if either the battery pack is connected with the wrong

polarity or if the battery pack output is shorted on the battery pack circuit board.

7-11. General Maintenance

7-12. Removal

Use the following instructions to remove the Battery Pack Option from the meter:

1. Make sure the meter is turned off and unplugged from the power outlet.

2. Remove the screw from the bottom of the case and the two screws from the rear

bezel (as shown in Figure 7-2 detail A). While holding the front panel, slide the case

and rear bezel off the chassis. (See Figure 7-2 detail B.) At this point, the rear bezel

is not secured to the case.

3. Locate the flat white battery pack option cable connector at the Main PCA (see

Figure 7-3.) Use needle nose pliers to detach this connection; alternately pull up on

each end of this connector.

7-6

Option -01 Battery Pack

General Maintenance

Rear Bezel

Mounting Screw (2)

Case

Grounding Screw (2)

Chassis

qb14f.eps

Figure 7-2. Removing the Case

4. Remove the two #6-32 x 1/4" panhead Phillips screws securing the Battery Pack

Option (see Figure 7-4).

5. Carefully slide the Battery Pack Option out of the meter (as shown in Figure 7-4).

Do not pinch the wires running from the circuit board to the battery terminals.

Caution

To prevent damage to the meter when servicing the Main PCA,

unplug the battery pack ribbon cable at the Main PCA or

disconnect the wires to the battery pack.

7-13.

Installation

Use the following instructions to install the Battery Kit Option. Refer to the Instruction

Sheet (PN 856013 - supplied with the Battery Kit) for the more detailed instructions

required with an initial installation of the Battery Kit Option.

1. Make sure the meter is turned off and disconnected from line power.

2. With the meter disconnected from line power, discharge the power supply capacitor

by turning the meter on. After five seconds, turn the meter off.

3. Carefully slide the battery kit into the area reserved for it in the back of the meter (as

shown in Figure 7-4). Make sure that both the retaining slots line up and the

mounting holes mate. Do not pinch wires running from the circuit assembly to the

battery pack terminals.

4. Secure the battery kit with two #6-32 x 1/4" panhead Phillips screws.

5. Attach the flat, white connecting cable at the Battery Pack Option circuit board (see

Figure 7-3). The single blue line of the cable should be to the rear of the meter.

Align the plastic socket on the cable end, then seat it securely in place.

6. Reinstall the meter case to seat properly in the front panel. Attach the rear bezel with

the two panhead Phillips screws, and secure the case with the flathead Phillips screw

in the bottom.

7-7

Option -01 Battery Pack

Performance Testing

qb34c.eps

Figure 7-4. Battery Pack Option Connecting Cable

7-14. Performance Testing

7-15. General Operability

The following performance verification assumes the following initial setup

configuration:

• The Battery Pack Option is physically installed in the meter.

• The red and black battery pack wires have been disconnected.

Refer to Table 7-1 for description of any equipment that is required during the

performance tests.

1. Disconnect the meter from line power. Now turn meter power on (1 = on), then off

(0 = off).

Note

Do not connect the battery pack until after the option assembly is turned

on later in this procedure.

2. Connect the 1.8 kΩ resistor across the battery pack wires. Connect the voltmeter

(Low to TP1 and High to TP2.)

3. Connect the meter to line voltage, but do not turn the meter on.

4. Check for a voltmeter reading of 9.35 V ±0.01V.

5. Now turn power on. Check for a voltmeter reading of 9.25 V ±0.01 V.

6. Remove the voltmeter and the 1.8 kΩ resistor.

7-9

Service Manual

7. Observing the polarity markings on the battery pack, connect the red wire to the

positive (+) terminal. Then connect the black (or brown) wire to the negative (-)

terminal. Reversal of these connections causes fuse F1 to open.

7-16.

Low Battery Indicator Detector and Low Battery Disconnect Test

The following test is necessary only after repairs have been made to either the Low

Battery Indicator Detector or the Low Battery Disconnect circuit.

Turn the meter OFF.

Unplug the two battery pack connectors from the battery pack terminals. Observing

the correct polarity, connect the variable power supply to the two battery pack

connectors.

Connect the voltmeter across the variable power supply.

Set the variable power supply to approximately 9 volts.

Now turn the meter ON, and check for correct operation of the Low Battery

Indicator symbol.

• While watching the display, slowly lower the variable voltage power supply

output. Check that the low battery indicator symbol comes on at 7.7 ±0.25 V dc.

• Now, slowly increase the variable voltage supply output. Check that the low

battery indicator symbol goes out at about 8 V dc.

Check the Low Battery Disconnect point.

• With the meter still operating on the variable supply, slowly lower the voltage,

and check that the meter goes OFF at about 7.0 V dc.

• After the meter goes OFF, slowly increase the voltage, and check that the meter

does not come ON before approximately 8.0 V dc.

Note

The meter may not come on, above 8 volts until the power is cycled.

There are no adjustments to set the Low Battery Indicator point or the Low Battery

Disconnect point.

7-17.

Cycle/Float Charge Rate Switch Test

Use the following procedure to verify operation of the meter's Cycle/Float Charge Rate

Switch. Note that this test is required only after repairs have been performed on the

Cycle/Float Rate Switch Test circuits.

1. Turn the meter OFF.

2. For this procedure, use a battery simulator as a substitute for the regular battery

pack. Connect this simulator (shown in Figure 7-5) as follows:

• Connect a 33Ω, 5W load resistor in parallel across the output of a variable

voltage power supply.

• Disconnect the battery charger wires from the battery.

• Connect the simulator to the battery charger wires. Install a 0.1Ω shunt resistor

in series with the red wire.

• Connect a voltmeter across the shunt resistor to measure the voltage drop across

and the charging current through the resistor.

7-10

Option -01 Battery Pack

Calibration

3. With no ac line power applied to the meter, adjust the variable voltage power supply

for 8.5 V dc output.

4. Now apply ac line power, and check that the charging current is greater than 250

mA.

5. Slowly increase the variable voltage supply output. Check for the following:

• The charging current decreases as the supply voltage approaches 10 V dc.

• The current should continue to decrease as the voltage increases, until the

current is between 60 and 80 mA.

• With any additional decrease in current (increase of the supply voltage), the

current should suddenly jump to a low value (less than 0.5 mA.)

• When the variable voltage supply output is reduced to 9.35 V dc, the current

should be between 5 and 15 mA.

OPTIONAL VOLTMETER

METER TO MEASURE

TO MONITOR A BATTERY VOLTAGE

CHARGING CURRENT

.1Ω SHUNT

RED

POWER SUPPLY

Ω

0 TO 15V

5Ω

BLACK

BATTERY OPTION PCA

qb36f.eps

Figure 7-5. Cycle/Float Charge Rate Switch Test

7-11

Service Manual

7-18. Calibration

The Battery Pack Option is adjusted at the factory for optimum performance and should

not require adjustment when installed. However, if either of the two adjustment pots on

the top of the Battery Pack Option circuit assembly have been turned inadvertently, or if

the unit has been repaired, the following procedure can be used to reset the controls for

optimum battery life and proper power supply system performance.

The following equipment is needed to perform these adjustments:

• An 1800 Ω, 1/2 watt, 5% resistor

• A voltmeter

The following steps describe how to adjust the Battery Pack Option:

1. With the Battery Pack Option installed in the meter and with the meter disconnected

from line power, unplug the battery connectors from the battery + and - terminals

(Figure 7-6).

2. Install the 1800 Ω resistor across the battery pack connectors.

3. Connect the meter to line power and turn the meter ON.

4. Connect the test leads from another voltmeter across test points TP1 and TP2 on the

Battery Pack Option circuit assembly (as shown in Figure 7-7). Adjust the front

potentiometer (R39) (top of the Battery Pack Option circuit assembly) until the

voltmeter across the test points reads 9.25 V.

5. Turn the meter OFF.

6. Connect the test leads from another voltmeter across TP1 and TP2 on the battery

pack option circuit assembly. Adjust rear potentiometer R20 (top of the battery pack

option circuit assembly) until the voltmeter across the test points reads 9.35 volts.

(With the meter connected to line power and turned off, the charging voltage reads

approximately 9.35 volts.)

7. Disconnect the line cord from the meter.

8. Remove the 1800 Ω resistor, and plug the battery pack connector wires back into the

battery pack (the red wire to + and the black wire to -.)

9. To ensure the battery pack connector wires are properly connected and the battery

kit is properly installed, turn the meter ON without plugging in the power cord.

7-12

Option -01 Battery Pack

Troubleshooting

View from bottom of instrument

Red

Black

Battery Connectors

qb37f.eps

Figure 7-6. Unplugging the Battery Pack Connectors

7-19. Troubleshooting

Troubleshooting can be facilitated by removing the Battery Pack Option and connecting

the Battery PCA with an extender cable (Fluke Part Number 854245). Refer to the

removal instructions provided earlier in this chapter.

With the meter off (but plugged into line power), check for approximately 16 V dc (at

120V ac line) raw dc supply between the ground test point and the cathode of either

A1CR2 or A1CR3. If necessary, check for transformer secondary voltage of

approximately 24 V ac.

Use an oscilloscope to trace the waveforms associated with the switching power supply.

• With the line voltage at 120 V ac, check the waveform at the drain of FET Q5. This

signal should be a 25 V p-p square wave, with the negative part at zero volts, a

period of 20 to 25 µs, and an ON duty ratio of .20 to .50. This square wave may

exhibit a damped sine wave (two to ten cycles) ringing on the trailing half of the

positive portion. The sine wave amplitude should be from 10 to 20 V p-p.

• Check for a 15 V p-p square wave at the gate of Q5.

• Check for a 14 V p-p square wave at U4-5.

• Check for a 0.5 V p-p sawtooth waveform (with a period of 20 to 25 µs) at U4-3.

Make sure that the oscilloscope is ac-coupled for this measurement.

Troubleshoot other sections of the Battery Pack Option assembly by making dc voltage

measurements. For circuit common, use the GND test point on the main circuit board or

the common end of R30 on the Battery Pack PCA. Note that the battery pack negative

terminal is not connected to common when the low battery disconnect circuit turns off

Q2.

7-13

Service Manual

Table 7-2. A4 Battery Pack PCA

Fluke

Total

Reference

Description

Note

Stock

Qty.

Designator

No.

6, 7

CAP,CER,1800PF,+-10%,50V,C0G,1206

769786

CAP,CER,33PF,+-10%,50V,C0G,1206

769240

CAP,AL,47UF,+-20%,50V,SOLV PROOF

822403

CAP,AL,10UF,+-20%,63V,SOLV PROOF

816843

CAP,AL,47UF,+-20%,100V,SOLV PROOF

837492

CAP,AL,1000UF,+-20%,16V,SOLV PROOF

837468

CAP,CER,0.22UF,+80-20%,50V,Y5V,1206

740597

CAP,AL,2.2UF,+-20%,50V,SOLV PROOF

769687

3, 5, 9

DIODE,SI,SCHOTTKY BARRIER,40V,1A

837732

4, 7, 8

DIODE,SI,BV=75V,IO=250MA,SOT23

830489

DIODE,SI,100 PIV,1.0 AMP

698555

DIODE,SI,100 PIV,3.3 AMP,SCHOTTKY

837740

FUSE,.095X.28,5A,125V,FAST,AXIAL

696427

HEADER,1 ROW,.050CTR,10 PIN

831503

2, 5

TRANSISTOR,SI,NMOS,1W,D-PAK

822106

3, 7

TRANSISTOR,SI,PNP,SMALL SIGNAL,SOT-23

742684

4, 6, 12, 13

TRANSISTOR,SI,NPN,SMALL SIGNAL,SOT-23

742676

RES,MOX,1.5K,+-5%,1W

603685

3, 42

RES,CERM,47K,+-5%,.125W,200PPM,1206

746685

RES,CERM,130K,+-5%,.125W,200PPM,1206

851761

RES,CERM,523K,+-1%,.125W,100PPM,1206

844956

RES,CERM,100K,+-1%,.125W,100PPM,1206

769802

RES,CERM,10.5K,+-1%,.125W,100PPM,1206

851852

16, 43

RES,CERM,10M,+-5%,.125W,300PPM,1206

783274

RES,CERM,470K,+-5%,.125W,200PPM,1206

746792

RES,CERM,330K,+-5%,.125W,200PPM,1206

746776

RES,CERM,51K,+-5%,.125W,200PPM,1206

746693

RES,VAR,CERM,10K,+-20%,0.3W

837559

RES,CERM,59K,+-1%,.125W,100PPM,1206

851803

RES,CERM,301K,+-1%,.125W,100PPM,1206

821652

RES,CERM,470,+-5%,.125W,200PPM,1206

740506

RES,CERM,3.3K,+-5%,.125W,200PPM,1206

746529

RES,METAL FILM,2.26k,+-1%,0.5W

603693

26, 44

RES,CERM,10,+-5%,.125W,200PPM,1206

746214

RES,CERM,100K,+-5%,.125W,200PPM,1206

740548

RES,CERM,12,+-5%,.125W,200PPM,1206

845458

29, 34- 37

RES,CF,0.50,+-5%,0.25W

830646

RES,CF,560,+-5%,0.25W

810440

RES,CERM,100,+-5%,.125W,200PPM,1206

746297

32, 41

RES,CERM,1K,+-5%,.125W,200PPM,1206

745992

RES,CERM,120,+-5%,.125W,200PPM,1206

746305

RES,CERM,910,+-5%,.125W,200PPM,1206

769257

RES,VAR,CERM,200,+-20%,0.3W

837567

RES,CERM,6.8K,+-5%,.125W,200PPM,1206

746024

RES,CERM,2.2K,+-5%,.125W,200PPM,1206

746479

7-16

Chapter 8

Option -05 IEEE-488 Interface

Title

Page

8-1.

Introduction

8-3

8-2.

Theory of Operation

8-3

8-3.

Functional Block Description

8-3

8-4.

Detailed Circuit Description

8-3

8-5.

Main Assembly Connectors

8-3

8-6.

Address Decoding Circuit

8-3

8-7.

Isolation Circuits

8-4

8-8.

IEEE-488 Controller

8-4

8-9.

IEEE-488 Transceivers/Connector

8-5

8-10.

General Maintenance

8-8

8-11.

Removing the IEEE-488 Interface Option

8-8

8-12.

Installing the IEEE-488 Interface Option

8-9

8-13.

Performance Testing

8-9

8-14.

Troubleshooting

8-10

8-15.

Power-up Problems

8-10

8-16.

Communication Problems

8-10

8-17.

Failure to Select IEEE-488 Interface Option

8-10

8-18.

Failure to Handshake on IEEE-488 Bus

8-11

8-19.

Failure to Enter Remote

8-11

8-20.

Failure to Receive Multiple Character Commands

8-12

8-21.

Failure to Transmit Query Responses

8-12

8-22.

Failure to Generate an End or Identify (EOI)

8-12

8-23.

Failure to Generate a Service Request (SRQ)

8-12

8-24.

Schematic Diagram

8-12

8-25.

List of Replaceable Parts

8-12

8-1

Option -05 IEEE-488 Interface

Introduction

8-1.

Introduction

The IEEE-488 Interface turns the Fluke 45 into a fully programmable instrument for use

with the IEEE Standard 488.1 (1987) interface bus (IEEE-488 bus). With the IEEE-488

Interface, the Fluke 45 can become part of an automated instrumentation system.

8-2.

Theory of Operation

8-3.

Functional Block Description

The IEEE-488 Assembly (A5) requires power supply voltages, address, data and control

signals from the Fluke 45 Main Assembly (A1) to operate. The A5 assembly implements

the circuitry necessary to satisfy the IEEE-488.1 standard for programmable

instrumentation.

8-4.

Detailed Circuit Description

The IEEE-488 Assembly comprises the following functional blocks: the Main Assembly

Connectors, the Address Decoding Circuit, the Isolation Circuits, the IEEE-488

Controller, and the IEEE-488 Transceivers and Connector. These five blocks are

described in the following paragraphs. Signal names mentioned during this discussion

are:

ACON*AC line power on

IRQ2*IEEE-488 interrupt request

OPSIEEE-488 option sense

OPTSW* IEEE-488 option power switch control signal

8-5.

Main Assembly Connectors

The IEEE-488 Assembly interfaces with the Main Assembly through two ribbon cables

that mount to the 14-position and 20-position connectors on each assembly. The 20-pin

connector (A5J2) routes the 16-bit address bus from the Microprocessor (A1U6) to the

circuitry on the IEEE-488 Assembly. The 14-position connector (A5J3) passes the eight-

bit data bus and memory control signals between the two assemblies.

The IEEE-488 Assembly is powered by the +5.2V dc power supply (VCC) from the

Main Assembly. VCC is connected to the IEEE-488 Assembly via A5J3-1. The logic

common return (GND) is through A5J2-20.

8-6.

Address Decoding Circuit

When a memory read or memory write cycle intended for the IEEE-488 Controller

(A5U6) is in progress, the 13 address bits ADD(15) through ADD(3) from A1U6 are

decoded by A5U1, A5U2, and A5U5 to generate an active low chip-select signal. The

chip-select signal (A5U5-8) goes low when two events occur: OPTSW* (A5J3-12) is

near -5.2V dc (VEE), and the address bus indicates that the Microprocessor is accessing

memory between addresses 0028 and 002F hexadecimal (inclusive). When the Fluke 45

is operating on battery power, the Microprocessor turns off the power to the IEEE-488

Assembly by driving the OPTSW* signal (A5J3-12) to VCC. This signal drives A5U1-6

to about +4.3V dc (through A5CR1), disabling the Address Decoding Circuit.

8-3

Service Manual

8-7.

Isolation Circuits

The Isolation Circuits allow the Microprocessor to turn off power to the A5U6, A5U7,

and A5U8 components. These three components consume the majority of the power on

the IEEE-488 Assembly; normal meter operation on batteries is extended by

approximately 100% with this power isolation scheme.

The Microprocessor determines that the IEEE-488 Assembly is installed in the meter by

checking the state of the OPS signal (A5J2-18). This signal is pulled up to VCC by

resistor A1R39 and is shorted to logic ground on the IEEE-488 Assembly. If A1U6-29 is

low, the Microprocessor assumes that the IEEE-488 Assembly is installed. If the

ACON* signal (A1U6-33) is low (indicating operation on ac power), the Microprocessor

drives A1U6-28 high. As a result, the OPTSW* signal (A1U7-3) is driven to VEE, and

transistor A5Q1 turns on. This transistor passes current from the VCC power supply to

the VCC2 power supply to bias A5U6, A5U7, and A5U8. Normally VCC2 is

approximately 0.1V less than VCC.

When OPTSW* (A5J3-12) is near VCC (battery operation), diode A5CR1 and pulldown

resistor A5R1 cause the non-inverting octal tri-state buffer (A5U4) to be tri-stated off by

holding inputs A5U4-1 and A5U4-19 near VCC. This octal buffer isolates six

Microprocessor outputs (ADD(2), ADD(1), ADD(0), WR*, RD, and E clock) from the

IEEE-488 Controller (A5U6) when the meter is operating on batteries. A5U4 also

buffers the chip-select signal (A5U5-8) that goes to A5U6 and the interrupt output signal

from A5U6-10.

The eight bit data bus from the Microprocessor is isolated from A5U6 by an octal bus

transceiver with tri-state outputs (A5U3). This transceiver is enabled only when the

Address Decoding Circuit detects that a memory cycle for the IEEE-488 Assembly is in

progress and A5U3-19 is driven low. If the memory cycle is a read cycle, the R/W*

signal (A5U3-1) is high and the transceiver buffers the eight bit data from A5U6 to

A1U6. If the memory cycle is a write cycle, the R/W* signal (A5U3-1) is low and the

transceiver buffers the eight-bit data from A1U6 to A5U6.

8-8.

IEEE-488 Controller

The IEEE-488 Controller (A5U6) is an integrated circuit that performs the transfer of

information between the IEEE-488 standard bus and the Microprocessor. Once it has

been programmed by the Microprocessor via the eight register microprocessor interface,

A5U6 performs IEEE-488 bus transactions independently until it must interrupt the

Microprocessor for additional information or data.

The IEEE-488 Controller is clocked by a 921.6-kHz square-wave clock. This clock

(A5U4-5) is generated by buffering the E clock (A5U4-15) from the Microprocessor.

The IEEE-488 Controller uses this clock to run the internal state machines that handle

IEEE-488 bus transactions.

The IEEE-488 Controller can be given a hardware reset with either of the following two

methods:

• If the system reset signal RESET (A5J3-14) goes high or if OPTSW* (A5J3-12)

goes high, then NOR gate output A5U2-10 goes low, and the D flip-flop Q output

A5U9-9 goes low. This flip-flop output drives the reset input (A5U6-22), forcing the

IEEE-488 Controller into its reset state.

• When the meter is initially powered up, both RESET and OPTSW* are high, forcing

the IEEE-488 Controller reset input (A5U6-22) to be low. As long as OPTSW* is

high, VCC2 is near ground and A5U6 is not biased, so A5U6-22 is held low to avoid

sourcing current into A5U6-22 while A5U6 is unbiased.

8-4

Option -05 IEEE-488 Interface

Theory of Operation

When the Microprocessor drives OPTSW* to VEE to enable the VCC2 power supply,

the CLR* input to the D flip-flop (A5U9-13) goes high to enable the flip-flop. The Q

output (A5U9-9) remains low until the Microprocessor does an initial dummy memory

cycle to the IEEE-488 Controller (approximately 1 ms later.) The rising edge at the end

of the chip select signal (A5U9-11) clocks the flip-flop and causes the Q output to go

high. This action removes the hardware reset to the IEEE-488 Controller. This delay is

followed by another dummy read cycle and a series of six memory write cycles that

program the IEEE-488 Controller.

For each character that it receives or transmits, the IEEE-488 Controller generates an

interrupt to the Microprocessor. These interrupts are generated by driving the open-drain

interrupt output A5U6-10 low. This signal is buffered by a tri-state buffer whose output

at A5U4-3 drives the IRQ2* input to the Microprocessor low. When the Microprocessor

responds to the interrupt and takes the necessary actions by reading and writing registers

in the IEEE-488 Controller, both A5U6-10 and, subsequently, A5U4-3 go high again.

Resistor A5R3 provides a pull-up termination on open-drain interrupt output A5U6-10.

Tri-state buffer output A5U4-3 is pulled up by resistor A5R2 to terminate the IRQ2*

signal when the buffer is tri-stated off.

When the Microprocessor performs a memory cycle to the IEEE-488 Controller, the

lower three bits of the address bus that are buffered by A5U4 (ADD(2) through ADD(0))

select the register being accessed in A5U6. When a memory read cycle is performed,

chip-enable A5U6-3 goes low, and A5U6-5 (DBIN) goes high. These actions enable

A5U6, driving the contents of the selected register onto the data bus and through the data

bus transceiver to the Microprocessor. When a memory write cycle is performed, chip-

enable A5U6-3 goes low, and A5U6-4 (WE*) goes first low and then high to latch the

data being driven from the Microprocessor (through A5U3) into the IEEE-488

Controller.

The IEEE-488 Controller interfaces to the IEEE-488 Transceivers using an eight-bit data

bus, eight interface signals, and two transceiver control signals (A5U6-33 and A5U6-

24).

The controller-in-charge signal (A5U6-33), which should always be high, controls the

direction of the SRQ, ATN, IFC, and REN IEEE-488 transceivers in A5U8.

The talk enable output (A5U6-24) is either low when the IEEE-488 Controller is not

addressed to talk or high when the controller is addressed to talk. This signal determines

the direction of all IEEE-488 Transceivers except SRQ, ATN, IFC, and REN.

8-9.

IEEE-488 Transceivers/Connector

The IEEE-488 Transceivers (A5U7 and A5U8) are octal transceivers that are specifically

designed to exhibit the proper electrical drive characteristics to meet the IEEE-488

standard. These transceivers are configured to match the control signals available on the

IEEE-488 Controller. Assuming that A5U6-33 is always high, Table 8-1 describes the

transceiver direction control. The IEEE-488 Transceivers connect to a 24-position

connector, which mates with the ribbon cable leading to the IEEE-488 connector

mounted at the rear of the meter chassis.

8-5

Service Manual

qb42c.eps

Figure 8-3. IEEE-488 Module Assembly

8-10. General Maintenance

8-11. Removing the IEEE-488 Interface Option

The following instructions can be used for access and servicing an IEEE-488 Interface

Option that is already installed in a Fluke 45 Dual Display Multimeter. For initial

installation, refer to the Instruction Sheet (PN 856005) provided with the option.

1. Make sure the meter is turned off and unplugged from the power outlet.

2. Remove the screw on the bottom of the meter case and the two screws from the rear

bezel (as shown in Figure 8-1A). While holding the front panel, slide the case and

rear bezel off the chassis (see Figure 8-1B). (At this point, the rear bezel is not

secured to the case.)

3. Using needle nose pliers, disconnect the 24-line cable assembly at the IEEE-488

PCA by alternately pulling up on each end of its connector. See Figure 8-2.

4. Refer to Figure 8-3 for the remaining steps. Remove the panhead Phillips screw at

the rear of the IEEE-488 PCA.

8-8

Option -05 IEEE-488 Interface

Performance Testing

5. Using needle nose pliers, detach the two ribbon cables at the front part of the IEEE-

488 PCA. Alternately pull up on each end of the cable connectors.

6. Remove the IEEE-488 PCA, disengaging the assembly from both the small slot in

the side of the meter and the plastic standoff at the front corner of the assembly.

8-12.

Installing the IEEE-488 Interface Option

Use the following procedure to install the IEEE-488 Interface Option.

1. Turn the meter off, and unplug the power connection.

2. Check that the plastic standoff remains in the appropriate hole in the meter PCA

(narrow end of the standoff down; see Figure 8-3).

3. If necessary, install the two ribbon cables on the IEEE-488 PCA. Each cable fits in

only one socket and in only one direction. Make sure the cables lock firmly in place.

4. Attach opposite ends of the ribbon cables onto the Fluke 45 Main PCA.

5. Install the IEEE-488 PCA in the Fluke 45 with the dual ribbon cables facing the

front of the meter. The IEEE-488 PCA slips into the small slot in the side of the

meter. The end of the plastic standoff fits into the hole in the IEEE-488 PCA. Make

sure the IEEE-488 PCA is firmly gripped against the retainer on the standoff. The

rear of the IEEE-488 PCA should rest upon the support just forward of the

transformer.

6. Secure the rear of the IEEE-488 PCA with the panhead Phillips screw.

7. Connect the 24-line cable assembly to the IEEE-488 PCA. (See Figure 8-2.)

8. Reinstall the meter case so it seats properly in the front panel. Attach the rear bezel

with the two panhead Phillips screws, and secure the case with the flathead Phillips

screw in the bottom.

8-13. Performance Testing

Use the performance test program in Figure 8-1 to verify operation of the IEEE-488

Interface. This program is written for use with the Fluke 182A Instrument Controller and

its interpreted BASIC language. The program may be adapted to the language of any

IEEE-488 controller.

This performance test communicates to a meter that has been configured for IEEE-488

operation at address 0. Lines 160 and 170 initialize the IEEE-488 bus and send a

selective device clear to the meter. A multiple byte command is sent to the meter (by line

190) to clear the meter status. Another command sequence (including a query) is sent to

the meter by line 210; the meter asserts Service Request (SRQ) to signal that a response

is available. Lines 530 through 560 first poll the meter for status, then input the response

from the meter. Lines 230 through 270 test for proper operation and print the results.

8-9

Service Manual

140 IA% = 0%

! instrument IEEE address

150 S% = -1%

! initialize spl response

160 TERM

! terminate input only on EOI

170 INIT PORT 0

! initialize IEEE-488 bus

180 CLEAR @IA%

! selective device clear

190 PRINT @IA%,"*cls"

! clear instrument status

200 ON SRQ GOTO 530

! enable SRQ interrupt

210 PRINT @IA%,"*cls;*sre 16;*idn?"

! SRQ on Message Available

220 WAIT 500% FOR SRQ

! allow time to execute commands

230 IF S% >= 0% THEN 260

240

PRINT "Instrument failed to generate a Service Request"

250

STOP

260 PRINT "Serial Poll =";S%;"(should be 80)."

270 PRINT "Identification Query Response = ";R$

280 STOP

500 !

510 ! Service Request interrupt

520 !

530 S% = SPL(IA%)

! get instrument serial poll status

540 IF S% AND 16% THEN 550 ELSE 560

550

INPUT LINE @IA%,R$

! if MAV set get the response

560 RESUME 230

! end of SRQ interrupt

999 END

Figure 8-4. IEEE-488 Interface Performance Test

8-14. Troubleshooting

8-15. Power-up Problems

The following discussion identifies probable fault areas if the installation of an IEEE-

488 Interface Option causes power-up failure for the Fluke 45. The problem is probably

a short on A5P2 or A5P3; the Microprocessor on the Main Assembly is prevented from

accessing ROM and RAM correctly. Two extender cables are available (PN 867952 and

867957) to assist during troubleshooting.

• The first thing to check is whether GND is shorted to either VCC or VCC2 on the

IEEE Assembly.

• The short may also be an interface signal to either VCC, GND, or another interface

signal. The logical signals to check are DATA(7..0), ADD(15..0), RD*, WR*, E, and

RESET*.

• The short may be due to a CMOS input that has been damaged from static discharge;

the short is then detectable only when the circuit is powered up. Use an oscilloscope

to check activity on each of the interface signals. Verify that signals are able to

transition normally between 0 and 5V.

8-16. Communication Problems

8-17. Failure to Select IEEE-488 Interface Option

IEEE-488 Interface selection procedures are described in Chapter 3.

8-10

Option -05 IEEE-488 Interface

Troubleshooting

If the IEEE-488 Interface Option is not detected by Fluke 45 software, there may be a

problem with the OPS or ACON* signal. The IEEE Interface Option grounds the OPS

signal (A5P2-18), which is normally pulled up to VCC on the Fluke 45 Main Assembly.

The Microprocessor determines that the IEEE-488 Interface Option is not installed if

OPS (A1U6-29) is detected high.

Further, software does not allow the IEEE-488 Interface Option to be selected if the

ACON* signal is detected high. Since ACON* is high when the meter is operating on

battery power, the IEEE-488 Interface Option cannot be selected as the active interface

during battery operation. The displayed "IEEE" message is dim, and the battery indicator

blinks if the Fluke 45 software detects ACON* to be high when the option editor is

entered. The ACON* signal (A1U6-33) is low when the meter is operating from line

power.

8-18.

Failure to Handshake on IEEE-488 Bus

Check VCC2 with a voltmeter. When the Fluke 45 is operating on line power, VCC2

should be about 0.1V lower than VCC. VCC2 is controlled by the Microprocessor,

which sets A1U6-28 high when operating on line power and causes OPTSW* to be

driven to a -5.0V dc level. The OPTSW* signal controls the gate of FET switch A5Q1

on the IEEE-488 Interface Option to turn VCC2 on.

The Reset circuit consists of A5CR1, A5R1, A5U2, and A5U9. When the meter is

operating on batteries, the Reset circuit converts the OPTSW* signal to a digital signal

that disables access to A5U6. When operating from batteries, OPTSW* is at about 5.0V

dc, A5U2-9 is high, A5U2-10 is low, and A5U9-9 is low to reset A5U6 via pin 22.

When the meter is connected to ac line voltage again, this circuit resets A5U6. OPTSW*

transitions to -5.0V dc, A5U2-9 is low (near GND), A5U2-10 is high, and A5U9-9 stays

low until the Address Decoder detects a memory access to the IEEE-488 Interface

Option. About 1.0 ms after OPTSW* goes to -5.0V dc, the initial read access clocks

A5U9-11, causing A5U9-9 to go high to remove the reset from A5U6-22. This action is

followed by another "dummy" read cycle for delay. The Main Assembly then sends six

write cycles to initialize A5U6. The IRQ2 interrupt is then enabled, and the serial poll

status byte is initialized. At this point, the IEEE-488 Interface Option is ready to respond

to transactions on the IEEE-488 bus.

Note

Each time that the IEEE Interface Option is selected in the BAUD menu

(by pressing [AUTO]), the IEEE-488 Interface Option initialization is

repeated as described above, with the exception that no hardware reset is

performed via the OPTSW* signal.

8-19.

Failure to Enter Remote

If the IEEE-488 Interface Option does not enter remote, check that the remote/local

control circuit is operating properly. When the IEEE-488 Interface Option is the active

instrument interface, the remote/local control state is polled by the Main PCA

approximately every 1.0 ms. Normally, A5U5-8 goes low for approximately 1.0 µs

during the read cycle that checks the state of A5U6. If A5U3-11 is low during the read

cycle, A5U6 is in the local state. If A5U3-11 is high during the read cycle, A5U6 is in

the remote state. When A5U6 indicates that it is in remote, the REMOTE indicator on

the display is turned on.

8-11

Service Manual

8-20.

Failure to Receive Multiple Character Commands

Monitor the interrupt signal from A5U6-10 during attempts to communicate with the

meter. Each byte received with the ATN signal (A5U6-31) high should cause the

interrupt signal to go low. Follow the interrupt signal through A5U4, and verify that it

arrives at A5J3 properly. If the interrupt is not detected by A1U6, it will remain low

indefinitely. A5U6-10 will only go high when both the interrupt is detected and the

received byte is removed from A5U6 by A1U6.

8-21.

Failure to Transmit Query Responses

Check that TE (A5U6-24) goes high when the interface is addressed to talk. This signal

must go high to allow the bus interface transceivers to change the direction of DIO1

through DIO8, EOI, DAV, NRFD, and NDAC. Verify that each of these signals passes

through A5U7 and A5U8 properly.

8-22.

Failure to Generate an End or Identify (EOI)

When the IEEE-488 Interface Option sends the Line Feed termination character with a

message, the EOI signal should also be set true. When EOI is true, A5U6-30 should go

low. Follow this signal from A5J1 through A5U8 to A5U6.

8-23.

Failure to Generate a Service Request (SRQ)

When a Service Request is being generated, A5U6-32 should be low. Follow this signal

through A5U8 to connector A5J1. When a Serial Poll (SPL) is performed by the IEEE-

488 bus controller, A5U6-32 will go high again.

Note

If the meter is in the remote state without front panel lockout (i.e., REMS),

a service request can be sent from the front panel by pressing [UPB].

8-24. Schematic Diagram

The schematic diagram for the IEEE-488 Interface Option is included in Chapter 9 of

this manual.

8-25. List of Replaceable Parts

Figures 8-4 and 8-5 provide illustration for the parts lists in Tables 8-3 and 8-4,

respectively. Refer to Chapter 6 for parts ordering information.

8-12

Service Manual

Table 8-3. A5 IEEE-488 Interface PCA

Fluke

Reference

Total

Description

Stock

Note

Designator

Qty.

No.

6- 11

CAP,CER,0.1UF,±10%,25V,X7R,1206

747287

CAP,CER,0.022UF,±10%,50V,X7R,1206

747279

DIODE,SI,BV=75V,IO=250MA,SOT23

830489

HEADER,2 ROW,.100CTR,24 PIN

831834

HEADER,1 ROW,.050CTR,20 PIN

831529

HEADER,1 ROW,.050CTR,14 PIN

831511

TRANSISTOR,SI,PMOS,1W,D-PAK

836544

1,3

RES,CERM,5.1K,±5%,125W,200PPM,1206

746560

RES,CERM,47K,±5%,.125W,200PPM,1206

746685

RES,CERM,220,±5%,.125W,200PPM,1206

746347

1,2

IC,CMOS,QUAD INPUT NOR GATE,SOIC

830711

IC,CMOS,OCTAL BUS TRANSCEIVER,SOIC

742577

IC,CMOS,OCTL LINE DRVR,SOIC

801043

IC,CMOS,8 INPUT NAND GATE,SOIC

830729

IC,NMOS,GPIB CONTROLLER,PLCC

887190

IC,LSTTL,OCTAL GPIB XCVR,SOIC

831651

IC,LSTTL,OCTAL GPIB XCVR,SOIC

831669

IC,CMOS,DUAL D F/F,+EDG TRG,SOIC

782995

8-14

FLUKE 45 Dual Display Multimeter. Service Manual (For IEC 1010 Meters Only) - page 3