Schiller AT-10 Service Handbook

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Cardiovit
ECG and

AT-10

Spirometry Unit

Service Handbook

SCHILLER AG

Altgasse 68

CH-6341 Baar, Switzerland

Phone: + 41 41 766 42 42

Fax: + 41 41 761 08 80

Home page: http://www.schiller.ch

April 2002 Article Number: 2. 540 005

i

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

AT-10 Service Handbook

Article Number 2. 540005

Issue 1: January 1993

Issue 2: July 1998

Issue c: April 2002

Associated Documents

Guide to SCHILLER Interpretation
and Measurement Program E / D / F Article No. 2.510179

SCHILLER AT-10 USER GUIDE - English Article No. 2.510127
SCHILLER AT-10 USER GUIDE - German Article No. 2.510126
SCHILLER AT-10 USER GUIDE - French Article No. 2.510128

© Copyright 2002 by SCHILLER AG

ii

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Where to Obtain Service

WELCH ALLYN SCHILLER Inc., 7420 Carroll Road, San Diego, CA , US-92121-2334
USA

USA / Canada

Asia Pacific

Tel.: [phone] Fax : [phone]
Home Page : www.welchallyn.com
SCHILLER Asia Pacific, 10 Jalan SS 3/33, Taman Universiti, 47300 Petaling Jaya, Selangor,

Malaysia
Tel.: + 603 7877 5336 Fax : + 603 7877 5744

Austria

France

Germany (EU
authorized
representative)

India

Italy

Switzerland

All other
countries

SCHILLER HmbH, Kampmüllerweg 24, A-4044 Linz, Austria

Tel.: + 43 732 709 90 Fax : + 43 732 757 000
SCHILLER Medical S.A, BP 50, 19, Avenue de la Gare, F-67162 Wissembourg / Cedex,

France
Tel.: [phone] Fax : [phone]

SCHILLER Medizintechnik GmbH, Rudolf-Diesel Strasse 14, D-85521 Ottobrunn, Germany

Tel.: + 4989 629 981 0 Fax : + 4989 609 509 0
SCHILLER Healthcare India Pvt. Ltd.,D.C.Silk Mills Compound, 'A' Wing, 1st floor, 5,

Chunawala Estate, Kondivitta Lane, Andheri - Kurla Road, Andheri (E, Mumbai - 400 059,
India

Tel.: + 9122 826 3520 Fax : + 9122 826 3525
ESAOTE Spa (SCHILLER ), Via di Caciolle 15, I-50127 Firenze, Italy
Tel.: + 39055 4229 201 Fax : + 39055 4229 208
SCHILLER Reomed AG, Riedstrasse 14, CH-8953 Dietikon, Switzerland
Tel.: [phone] Fax : + 411 740 3710
SCHILLER AG, Altgasse 68, CH-6341 Baar, Switzerland
Tel.: + 4141 766 4242 Fax : + 4141 761 0880
Home Page : www.schiller.ch

iii

Warranty

Disclaimer

The Information in this guide has been carefully checked for reliability; however no guarantee is
given as to the correctness of the contents and SCHILLER makes no representations or warranties
regarding the contents of this manual. We reserve the right to revise this document and make
changes in the specification of the product described within at any time without obligation to notify
any person of such revision or change.

Trademarks

SCHILLER and AT-10 are registered trademarks of SCHILLER AG. All trademarks are the
property of their owners.

Copyright Notice

© Copyright 1998 by SCHILLER AG. All rights reserved. You may not reproduce, transmit,
transcribe, store in a retrieval system or translate into any language, in any form or by any means,
electronic, mechanical, magnetic, optical, chemical, manual or otherwise, any part of this
publication without express written permission of SCHILLER AG.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Terms of Warranty

The SCHILLER AT-10 is warranted against defects in material and manufacture for the duration
of one year (as from date of purchase). Excluded from this guarantee is damage caused by an
accident or as a result of improper handling. The warranty entitles free replacement of the defective
part. Any liability for subsequent damage is excluded. The warranty is void if unauthorized or
unqualified persons attempt to make repairs.

In case of a defect, send the apparatus to your dealer or directly to the manufacturer.

The manufacturer can only be held responsible for the safety, reliability, and performance of the
apparatus if:

° assembly operations, extensions, readjustments, modifications, or repairs are carried out by
persons authorized by him, and

° the unit and approved attached equipment is used in accordance with the manufacturers
instructions.

THERE ARE NO EXPRESS OR IMPLIED WARRANTIES WHICH EXTEND BEYOND THE
WARRANTIES HEREINABOVE SET FORTH. SCHILLER MAKES NO WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE WITH RESPECT TO
THE PRODUCT OR PARTS THEREOF.

iv

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Safety Notices

TO PREVENT ELECTRIC SHOCK DO NOT DISASSEMBLE THE UNIT. NO SERVICEABLE
PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL ONLY.

DO NOT USE THIS UNIT IN AREAS WHERE THERE IS ANY DANGER OF EXPLOSION
OR THE PRESENCE OF FLAMMABLE GASES SUCH AS ANAESTHETIC AGENTS.

IF THE DISPLAY IS DAMAGED, A LEAKAGE OF FLUID MAY OCCUR. DO NOT INHALE
THE VAPOUR FROM THIS FLUID AND AVOID CONTACT WITH MOUTH AND SKIN. IF
CONTACT IS MADE, CLEAN CONTAMINATED AREA IMMEDIATELY WITH FRESH
WATER.

THIS PRODUCT IS NOT DESIGNED FOR STERILE USE.
SWITCH THE UNIT OFF BEFORE CLEANING AND DISCONNECT FROM THE MAINS.
DO NOT, UNDER ANY CIRCUMSTANCES, IMMERSE THE UNIT OR CABLE ASSEMBLIES

IN LIQUID.
DO NOT OPERATE THE UNIT IF THE EARTH CONNECTION IS SUSPECT OR IF THE

MAINS LEAD IS DAMAGED OR SUSPECTED OF BEING DAMAGED.
DO NOT USE HIGH TEMPERATURE STERILISATION PROCESSES (SUCH AS

AUTOCLAVING). DO NOT USE E-BEAM OR GAMMA RADIATION STERILISATION.
DO NOT USE SOLVENT CLEANERS
USE ONLY ACCESSORIES AND OTHER PARTS RECOMMENDED OR SUPPLIED BY

SCHILLER AG. USE OF OTHER THAN RECOMMENDED OR SUPPLIED PARTS MAY
RESULT IN INJURY INACCURATE INFORMATION AND/ OR DAMAGE TO THE UNIT.

THE AT-10 COMPLIES WITH EMC REGULATIONS FOR MEDICAL PRODUCTS WHICH
AFFORDS PROTECTION AGAINST EMISSIONS AND ELECTRICAL INTERFERENCE.
HOWEVER SPECIAL CARE MUST BE EXERCISED WHEN THE AT-4 IS USED WITH
HIGH FREQUENCY EQUIPMENT.

IT MUST BE ENSURED THAT NEITHER THE PATIENT NOR THE ELECTRODES
(INCLUDING THE NEUTRAL ELECTRODE) COME INTO CONTACT WITH OTHER
PERSONS OR CONDUCTING OBJECTS (EVEN IF THESE ARE EARTHED).

THERE IS NO DANGER WHEN USING THE ECG UNIT FOR A PACEMAKER PATIENT OR
WITH SIMULTANEOUS USE OF OTHER ELECTRICAL STIMULATION EQUIPMENT.
HOWEVER, THE STIMULATION UNITS SHOULD ONLY BE USED AT A SUFFICIENT
DISTANCE FROM THE ELECTRODES. IN CASE OF DOUBT, THE PATIENT SHOULD BE
DISCONNECTED FROM THE RECORDER.

v

Safety Notices

THIS UNIT IS CF CLASSIFIED ACCORDING TO IEC 601-1. THIS MEANS THAT THE
PATIENT CONNECTION IS FULLY ISOLATED AND DEFIBRILLATION PROTECTED.
SCHILLER CAN ONLY GUARANTEE PROTECTION AGAINST DEFIBRILLATION
VOLTAGE, HOWEVER, WHEN THE ORIGINAL SCHILLER PATIENT CABLE IS USED.

WHEN NON-MEDICAL DEVICES ARE CONNECTED TO THE RS-232 INTERFACE ENSURE
THAT BOTH UNITS ARE SECURELY CONNECTED TO THE SAME EARTH POTENTIAL.

WHEN OPERATING THE UNIT ON BATTERY AND SIMULTANEOUSLY USING NON­MEDICAL DEVICES, THE RS-232 INTERFACE MUST BE FULLY ISOLATED.

BEFORE USING THE UNIT, ENSURE THAT AN INTRODUCTION REGARDING THE
UNIT FUNCTIONS AND THE SAFETY PRECAUTIONS HAS BEEN PROVIDED BY A
SCHILLER REPRESENTATIVE.

THE GUIDELINES FOR PATIENT ELECTRODE PLACEMENT ARE PROVIDED AS ON
OVERVIEW ONLY. THEY ARE NOT A SUBSTITUTE FOR MEDICAL EXPERTISE.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

THE AT-10 ECG UNIT IS PROVIDED FOR THE EXCLUSIVE USE OF QUALIFIED
PHYSICIANS OR PERSONNEL UNDER THEIR DIRECT SUPERVISION. THE NUMERICAL
AND GRAPHICAL RESULTS AND ANY INTERPRETATION DERIVED FROM A
RECORDING MUST BE EXAMINED WITH RESPECT TO THE PATIENTS OVERALL
CLINICAL CONDITION. THE RECORDING PREPARATION QUALITY AND THE
GENERAL RECORDED DATA QUALITY, WHICH COULD EFFECT THE REPORT DATA
ACCURACY, MUST ALSO BE TAKEN INTO ACCOUNT.

IT IS THE PHYSICIANS RESPONSIBILITY TO MAKE THE DIAGNOSIS OR TO OBTAIN
EXPERT OPINION ON THE RESULTS, AND TO INSTITUTE CORRECT TREATMENT IF
INDICATED.

vi

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

What´s in this Book

THE SERVICE PHILOSOPHY FOR ALL SCHILLER UNITS IS FAULT FINDING TO
MODULE LEVEL. THE PURPOSE OF THIS BOOK IS TO PROVIDE ALL THE INFORMA­TION NECESSARY TO ENABLE THE SERVICE ENGINEER TO EFFICIENTLY LOCATE
AND REPLACE A FAULTY MODULE. THIS BOOK ASSUMES NO DETAILED KNOWL­EDGE OF THE AT-10 BUT DOES REQUIRE THAT THE SERVICE ENGINEER IS FAMIL­IAR WITH STANDARD WORKSHOP PRACTICES.

The book is divided into the following chapters:

Chapter 1 - Operating Elements

The purpose of this chapter is to provide an easy reference for all the main operator functions and
to give a basic introduction to the AT-10. This chapter gives details of the operator controls with
the operation and function of each key briefly explained. The information in this chapter provides
a background to the operating functions only. Complete operating information is provided in the
SCHILLER AT-10 Operating Manual.

Chapter 2 - Functional Overview

This chapter provides a functional overview of the AT-10 The functional description is supported
by functional block diagrams.

Chapter 3 - Fault Diagnosis

This chapter provides a guide to locate a fault to module level. The diagnostics are presented in a
logical sequence of fault finding algorithms and procedures. Illustrations are provided to support
the text where needed.

Chapter 4 - Physical Overview & Module Replacement

This chapter gives an overview of the physical construction of the AT-10 with the main physical
attributes of the unit briefly described. The physical description is supported by illustrations
showing the internal location of all modules. Removal and Replacement instructions for all
replaceable modules are also provided in this chapter. Each procedure is autonomous with details
of tools, jumper settings, adjustments, and settings or special requirements that are required before
and after replacement. Functional checks that must be carried out after replacing a new module are
also provided.

Chapter 5 - Functional Checks & Adjustments

This chapter provides all adjustments and settings. Also detailed in this chapter are basic functional
test procedures that can be performed to check the functioning of the unit.

Chapter 6 - Spare Parts

This Chapter provides the part numbers and reordering information for all replaceable modules.
Also included in this chapter are details of any special test equipment or special tools required for
adjustment or fault finding procedures.

Chapter 7 - Technical Data

The full technical specification of the AT-10 is given in this chapter.

Chapter 8 - Glossary

This Chapter explains all the acronyms and signal titles used in this book and in the AT-10 circuit
diagrams.

vii

What´s in this Book

Circuit Diagrams & Board Layouts

The circuit diagrams and component layouts are provided for all boards. These details are provided
for information only.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

viii

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Introduction 1.2
The Keyboard 1.4

Alpha Numeric Keypad 1.4
General Purpose Keys 1.4
Control Keys 1.6
Function Keys 1.7
Resting ECG Function Keys 1.7

Exercise Function Keys 1.8

Connector Panels 1.9

Side Panel 1.9
Back Panel 1.10
Mains Panel 1.11

Liquid Crystal Display 1.12
Calibration 1.13

Manual Baseline Reset 1.13

System Setup 1.14

Defining Macro Functions 1.14
Save Settings 1.15

ECG Menu 1.16
Filters 1.17

Baseline Filter 1.17
Myogram Filter 1.17
Mains Filter 1.17

Number of Printed Copies 1.18
Lead Sequence 1.19
User-programmable Lead Group 1.20
Programmable channels for Printout 1.21

Chapter 1

Operating Elements

Chapter 1

Operating Elements

Contents

1.7

Page 1.1

Chapter 1
Operating Elements

Introduction

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

The Schiller Cardiovit AT-10

The CARDIOVIT AT-10 is a sophisticated compact work-station for cardiological diagnosis. It has
the facility to carry out both resting and exercise ECGs with the test results displayed on the integral
LCD and recorded on the built-in thermal printer.

Three RS-232 interfaces and one RS-422 interface are provided for the connection of digitally
controlled exercise test equipment, blood pressure equipment, and for data transmission/reception.
The unit also has facilities for connection of an external video monitor, experimental DC inputs, and
analog controlled exercise equipment.

With ECG program options, the AT-10 can be upgraded to provide ECG interpretation, exercise
test evaluation, pacemaker measurement and Frank vector loops. A Spirometry option enables
Spirometry tests to be performed and pulmonary function diagnosis to be carried out.

The AT-10 can also be connected to the Schiller PC-based data management program (designated
SEMA-200), for the validation and archiving of recorded data.

Page 1.2

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Introduction (cont.)

The main operating and connection modules of the Cardiovit AT-10 are as follows:

l Keyboard The keyboard is divided into three functional areas. The

l LCD Screen The LCD screen displays the real-time ECG traces and

l Thermal Printer The printer provides hard copy of test results.
l Right-hand Side Panel The side panel contains dc input connectors, the ECG

Chapter 1

Operating Elements

top area comprises the unit ON/OFF keys, the paper tray
key and other general function keys. The central area
contains dedicated control and function keys, and the
bottom area contains the alpha-numeric keys and other
general function keys.

certain operating and status information. Under operator
control the display also gives menu options and displays
operator entered data. The display is folded down when not
in use.

patient connector, the Spirometry connector and RS serial
connectors. When the floppy disk storage option is installed,
the disk drive is installed on this side panel.

l Left-hand Side Panel This panel contains the paper tray and (below the paper

tray) the program pack.

l Rear Panel The rear panel contains the data input/output connector,

the external video monitor and the ERGO connector. The
rear panel also contains the mains connector with on/off
switch, voltage selector and mains fuse. When the LAN
option is installed the LAN connector is mounted on the
back panel

Page 1.3

Chapter 1
Operating Elements

The Keyboard

Alpha Numeric Keypad

The functions of the dual purpose keys on the alphanumeric keyboard are as follows:

KEY FUNCTION

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

DUAL PURPOSE KEYS

'1' to

'7'

Printout Speed Selection 2.5, 5, 10, 12.5, 25, 50, or 100

mm/s

'8' to `_ Printout Sensitivity Selection 2.5, 5, 10, or 20 mm/mV

General Purpose Keys

The general purpose keys to the right of the alpha-numeric keypad, are as follows:

Page 1.4

The direction keys are used to move the cursor in order to make menu selections

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

The Keyboard (cont.)

Chapter 1

Operating Elements

The top line of the keyboard is dual purpose and when the unit is in the ECG mode, these keys double
as control for the direct setting of speed and sensitivity for manual printout. Otherwise, the
alphanumeric keyboard serves as a normal keyboard for data input.

Page 1.5

Chapter 1
Operating Elements

The Keyboard (cont.)

Control Keys

The Control keys are situated at the top of the keyboard and contain the function keys which are
common to all function modules. The control keys are as follows:

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 1.6

Note: Slight functional differences may exist in different modes

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

The Keyboard (cont.)

Function Keys

The function keys are arranged in a group in the middle of the keyboard. The left part of the group
comprises keys for the resting ECG recording functions. The middle part comprises keys for the
Exercise ECG functions. On the right hand side is the SPIRO key for the optional pulmonary
function testing program. The following is a summary of the keys and their functions:

Resting ECG Function Keys

Chapter 1

Operating Elements

Page 1.7

Chapter 1
Operating Elements

The Keyboard (cont.)

Exercise Function Keys

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 1.8

* The grade increases when pressed in conjunction with the YES (+) key and decreases when

pressed in conjunction with the NO (-) key.
The Speed/Load increases when pressed in conjunction with the YES (+) key and decreases

when pressed in conjunction with the NO (-) key.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Connector Panels

Side Panel

Chapter 1

Operating Elements

The following are located on the side panel:

1. 1 X RS-232C interface for connection of a bicycle with blood pressure measuring device
(Port 1)

2. 1 X RS-232C interface for connection of an ergometer (bicycle or treadmill) (Port 2)

3. 1 X RS-232C interface for data transfer (Port 3)

4. 1 X RS-422 interface for data transfer

5. LCD contrast control

6. DC inputs: DC2 0.5V/cm

7. DC inputs: DC1 0.5V/cm

8. Connection for SP-20, SP-150, SP-110 or SP-110/R flow sensor for lung function
measurements (Option)

9. Test socket for electrode leads with control light

10.EKG / ECG Socket for patient cable

Note: The socket is CF rated ie fully floating and isolated, defibrillation protected, suitable

for intra-cardiac application.

Page 1.9

Chapter 1
Operating Elements

Connector Panels (cont.)

Back Panel

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

The following connectors are located on the back panel:

1. Identification Plate

2. Mains Module

3. Connector for external video

4. Exercise (stress) test connection for analogue ergometers (bicycle or treadmill)

5. Data I/O socket for connection of foot-switch, QRS trigger, treadmill elevation control

6. Potential equalisation (ground) connection

7. Local area network Connector (Option)

Page 1.10

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Connector Panels (cont.)

Mains Panel

Chapter 1

Operating Elements

The following are located on the mains panel:

1. Mains fuse (200 mA slow) and voltage selector

2. Mains connection

3. Voltage indicator (mains)

4. Power on / off switch

Page 1.11

Chapter 1
Operating Elements

Liquid Crystal Display

The liquid crystal display (LCD) performs both as a real-time monitor and as an alphanumeric
display for menu selection, data input and the provision of important information.

The display can be folded down when not in use. The contrast can be adjusted by means of the LCD
control located on the side panel of the unit.

A typical display of an ECG recording (with patient simulator connected) is as follows:

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Depending on the function, the displayed information will vary but the screen is normally divided
into three general area as follows:

l The top of the screen gives status and operating information. These are permanently

displayed.

l The central part of the screen is taken up with the measured waveform (ie ECG trace, Lung

function curve, etc) with the lead identifications or measurement units on the left-hand side.

l The bottom of the screen displays the time interval of the recording, indicated in seconds.

The very bottom line gives, from left to right:

• Selected Baseline and Myogram filter settings

• Speed, sensitivity and the number of channels (for direct (manual) print-out)

• The leads that are selected for the printout (for direct (manual) print-out)

Page 1.12

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Calibration

At any time during the ECG recording, a 1mV calibration signal can be manually produced by
pressing the <1mV> key on the keyboard. This 1mV square wave signal is indicated both on the
display and on the printout.

Manual Baseline Reset

Pressing the manual baseline recentre key resets the displayed traces to the optimal
position. Use this key to centre the real-time ECG traces, when `drifting´ occurs.

Chapter 1

Operating Elements

Page 1.13

Chapter 1
Operating Elements

System Setup

There are several general settings for the AT-10. Press the <FNCT> key to call up the initial menu.
Two options are presented. Option 1 is for entry of the operator information - MTA (Medical
technical Assistant). The second menu item is the set-up option. Press <2> and the System Setup
menu is displayed as follows:

When the menu is entered, the cursor is always located on the first item. There are two ways to select
a particular menu item as follows:

• press the number indicated to the left, or

• use the direction keys to move the cursor to the item required and press the <ENTER> key.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Most of the options are self explanatory in the set-up menu, however the macro function and the save
setup options are detailed here.

Defining Macro Functions

With the AT-10 you can create your own macro functions and assign them to one of the first six
numerical keys on the alphanumeric keyboard. Up to 30 keystrokes can be stored for one macro
enabling you to call up a particular sub-menu or to carry out a particular programming sequence by
pressing only two keys.

Note: Before starting to program a macro, it is advisable to carry out the sequence making

a note of the order of the key strokes for reference.

In the System Setup menu, press key <1> to call up the Macro function input menu. To start the
programming sequence, press key <I> , then the number key which you wish to program and then
carry out the required sequence.

Once the sequence is completed, press the <2nd> key followed by the <ESC> key and storage of
the keystroke sequence is confirmed by an audible tone.

To initiate a programmed Macro sequence, press the <2nd> key and then the programmed number
key on the alphanumeric keyboard. The sequence will remain stored until a new sequence
overwrites the existing macro programmed for that key.

Page 1.14

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

System Setup (cont.)

Save Settings

Programmable parameters can be stored as base settings. These stored settings are not erased when
the unit is switched off. To call up this function, select the last item in the System Setup menu and
the Save Settings menu is displayed as follows:

Chapter 1

Operating Elements

See the AT-10 Operating Manual for full explanation. By pressing <ENTER>, the actual
configuration will be permanently stored and confirmation is given with the message:

*** Settings memorized! ***.

By pressing key "X" the factory default settings are activated. Press <ENTER> and these settings
are stored and confirmed through the message:

*** Settings memorized! ***.

Page 1.15

Chapter 1
Operating Elements

ECG Menu

To call up the menu for any of the main functions, simply press the respective function key (eg
<ECG> for resting ECG, <EXERCISE> for exercise ECG, etc). To return from any menu directly
to the Monitor mode, press the <FNCT> key. To return from any menu to the previous menu, press
the ESC key. To call up the main resting ECG menu, press the ECG key.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 1.16

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Filters

There are five filters which can be set before starting the recording of an ECG. To call up the menu
for these filters, press the <ECG> key, then select option `ECG Settings´ followed by 'Filters´. The
following menu is displayed:

Chapter 1

Operating Elements

Baseline Filter

A digital baseline filter has been designed in order to suppress excessive baseline drifts. By pressing
key <1> (for resting ECGs) or key <2> (for exercise ECGs), the setting can be altered to one of the
following values: 0.50, 0.25, 0.12 or 0.05 Hz. The value set is the lower limit of the frequency range
and is normally set to 0.05Hz (IEC recommendation), i.e. a frequency range of 0.05 to 150Hz.

The settings 0.12, 0.25 and 0.50Hz should only be used when absolutely necessary as the possibility
exists that they could affect the original ECG signal, especially the ST segments.

Pressing key <4>, <5> or <7> toggles the smooth filter, the baseline stabilisation or the pacemaker
detection circuit on or off.

The current baseline filter setting is indicated at the bottom of the screen. Once the setting has been
changed, firstly press the <FILTER> key in order to reset this indication.

Myogram Filter

The myogram filter suppresses disturbances caused by strong muscle tremor. This filter can be
switched on and off by pressing the <FILTER> key. When set to off, the displayed setting will be
150Hz. When set to on, the selected cut-off frequency (25 or 35Hz) will be indicated.

To alter the setting for the filter, press key <3> and the cut-off frequency can be set to either 25 or
35Hz. The current Myogram filter setting is indicated at the bottom of the screen to the right of the
baseline filter setting. Once the setting has been changed, press the <FILTER> key in order to reset
this indication.

The stored ECG can be printed either with or without passing the myogram filter.
Note: Using the myogram filter causes wave amplitudes on the printout to be reduced by as

much as 20%. Average cycles and measurement values however are not affected by
this filter.

Mains Filter

The mains filter is an adaptive 50Hz / 60Hz digital interference filter designed to suppress ac
interference without attenuating or distorting the ECG. By pressing key <6>, the filter can be set
according to country requirements to either 50Hz (for most European countries) or 60Hz (for the
USA) or switched off.

Page 1.17

Chapter 1
Operating Elements

Number of Printed Copies

The number of copies to be printed out can be pre-selected. To do this, press the <ECG> key, select
the ECG Settings / Further Settings menu option and then select ''Number of copies'' (1).

Press key <1> several times to select the required number of copies (either 1, 2, 3, 4 or none).

The unit will now produce the specified number of ECG copies whenever the <AUTO START>
or <COPY> key is pressed.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 1.18

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Lead Sequence

The lead sequence can be set to either Standard or Cabrera. The sequence required can be selected
by pressing the <ECG> key, selecting the ECG Settings / Further Settings menu option and then
selecting ''12 Lead Sequence'' (2).

Press key <2> to toggle between Standard and Cabrera leads.

Standard Cabrera

I VI II V4 aVL V1 II V4

II V2 aVF V5 I V2 aVF V5

III V3 III V6 -aVR V3 III V6

aVR V4 V2 V7 II V4 V2 V7

Chapter 1

Operating Elements

Lead Groups

aVL V5 V4 V8 aVF V5 V4 V8

aVF V6 V5 V9 III V6 V5 V9

Page 1.19

Chapter 1
Operating Elements

User-programmable Lead Group

The user-programmable group comprises 12 leads which can be individually programmed. To
program these leads, press the <ECG >key, select the ECG Settings menu option and then select
''Programmable Leads'' (5). The following table is then displayed:

The display shows the leads currently programmed. The numbers 1 to 12 symbolise the order of the
leads and the actual lead identifications show which lead is in which position in the group.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

To program your own lead group, simply enter the code number of the lead you require and press
it several times to select the lead that you want. As an example, to select lead V1 as the first lead,
press key <1> several times until lead V1 is displayed. All leads can be programmed in this way.

Page 1.20

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Programmable channels for Printout

The number of channels for the printout can be set to either 3, 4 (5,7), 6 or a user-defined number.
To set this user-defined number, press the <ECG> key, select the ECG Settings / Further Settings
menu option and then select ''Programmable Channels'' (3).

Press key <3>, several times to select the required number of channels (ie, 4, 5 or 7). This setting
is particularly useful when, for example, additional Doppler or Phono waveforms are to be recorded
through the experimental inputs.

Note: Selection of the number of channels (ie, 3, 4 or 6) is performed by pressing the

<PRINTER CHANNEL> key and the current selection is indicated at the bottom of
the screen.

Chapter 1

Operating Elements

Page 1.21

Chapter 1
Operating Elements

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 1.22

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Block Diagram 2.3
Brief Description 2.4
Overall Functional Description 2.7

Power Supply 2.7
Processor and Memory 2.7
ECG 2.7
Keyboard 2.8

Power Supply 2.11

On/Off Control and Low Battery Voltage Monitoring 2.11
Battery Controller 2.12

Processor Board 2.15

CPU 2.15
Program Pack 2.15
Memory 2.15
Communications Controller 2.16
Stress Analog Input/Output 2.17
Thermal Print Head Controller 2.17
Programmable Printer Timer and Beeper 2.17
Power On Reset 2.18

ECG Amplifier 2.20

ECG Isolated Power Supplies 2.20
Pacemaker Trigger 2.21
Cable Tester 2.22

Interface Board 2.23

Thermal Printer Control 2.23
Paper Carriage Control 2.25

Chapter 2

Functional Overview

Chapter 2

Functional Overview

Contents

Page 2.1

Chapter 2
Functional Overview

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 2.2

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Block Diagram

AT-10

P21

PAPER

DC

MOTOR

Chapter 2

Functional Overview

MAINS

DC 1
DC 2

SP-110/R

24 V

BATTERY

PROGRAM

PACK

MK 8-11

P27

POWER SUPPLY

P25
P26

P8
P9

P7

PROCESSOR

MK 8-6

P1

P1

MK 8-1

P20

P12

P2

STEPPER

MOTOR

PAPER
MARK

DETECTION

THERMAL

PRINT
HEAD

KEYBOARD

MK 8-3

LCD

RS-232 (x 3) AND

ONE RS-422

DATA I/O

MK 8-5

BUFFER

MK 8-4

MK 8-7

P22

P24

P23
P29

P13

P14
P15

INTERFACE

P20

LCD/KEYBOARD

P12

RS INTERFACE

P4

ECG

ECG AMPLIFIER

MK 7-20

P4

P3

P6

AT-10 Basic Block and Interconnection Diagram

ERGO

VIDEO

Page 2.3

Chapter 2
Functional Overview

Brief Description

The AT-10 comprises the following boards and major functional areas:
Power Supply The power supply rectifies the mains input and generates

Processor Board The Processor Board is the master control for all peripherals

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

all the required voltages for the AT-10 electronics. Two
rechargeable 12V batteries, connected in series, provide
the power for the printer and enable the AT-10 to operate
for about one hour when mains is not present.

and contains the main CPU, system timing circuits and the
unit RAM memory. This board also contains the following:

• Video signal generation circuits and the video/LCD
conversion circuit for the LCD

• Program Pack containing the unit software

• Print control, keyboard timing, and graphics control
circuits

The Processor Board communicates externally over the
following connectors:

• Serial RS-232 and RS-422 interfaces for connection of
RS controlled treadmills and blood pressure measuring
equipment. A port is also available for data transmission
to other ECG equipment or to an external computer for
data evaluation and storage.

• ERGO connector which provides an analog output to
control the speed of a treadmill or the load on a bicycle
ergometer. An analog signal is returned from a treadmill
to indicate the current elevation and speed.

• Data I/O connector which is used for the following:

- a foot-switch input

- QRS trigger output for BP-200

- control signal for treadmill elevation

• Video connector for connection of an external
monochrome VGA standard monitor. The digital video
signal reflects the current LCD display.

• Spirometry connector for connection of a spirometer
(SP-20, SP110, SP-150).

• DC connectors (DC1, DC2) which are used for
experimental analog input signals.

Page 2.4

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Brief Description (cont.)

ECG Amplifier Board This board amplifies and carries out some signal processing

Interface Board The Interface board contains the following:

LCD/Keyboard Buffer Board This board buffers the LCD and keyboard data and contains

Chapter 2

Functional Overview

on the incoming ECG signals. To ensure absolute safety of
the patient, all incoming/outgoing data is via opto-isolators.

• Paper mark detection circuit

• Thermal print head data buffers

• Stepper motor control circuit

• Control circuit for the paper tray dc motor

the high voltage circuit for the LCD.

Page 2.5

Chapter 2
Functional Overview

+UB

+ 5 V

- 18 V

± 12 V

SUPPLIES

UNIT POWER

(x 3)

RS-422

RS-232

DRIVER

COMMUNICATIONS

ERGO

DATA I/O

STRESS

ANALOG

INPUT / OUTPUT

VIDEO

GRAPHICS

CONTROLLER

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

LCD

BUFFER

VIDEO - LCD

CONVERTER

LCD/KEYBOARD

K/B

BUFFERMK 8-4

BUFFER

DISPLAY

KEYBOARD

VOLTAGE

REGULATION

POWER

CONTROL

ON/OFF

POWER SUPPLY MK 8-6

24V

VOLTAGE

REGULATION

RECTIFICATION

TO CPU

BATTERY CAPACITY

CHARGE

BATTERY

MONITOR

CONTROLLER

COMMUNICATIONS

EEPROM

STATIC AND

DYNAMIC RAM/

PACK

PROGRAM

CPU

MASTER

DATA

ADDRESS

CONTROL

ECG

Multiplexed

TIMER

PRINT HEAD

CONTROLLER

OPTO

ISOLATOR

MK 8-5

INTERFACE

POWER SUPPLY MK 8-6

HEAD BUFFER

THERMAL PRINT

DETECTION

PAPER MARK

MOTOR

DRIVER

PAPER TRAY

MOTOR CONTROL

PRINT HEAD

PHOTODETECTOR

PRINTER MOTOR

MOTOR

PAPER TRAY

AT-10 Functional Block Diagram

Page 2.6

MAINS

ISOLATION

TRANSFORMER

FILTER AND

VOLTAGE SWITCH

MAINS

A /D

CONVERTER

MK 8-1

BOARD

MICROPROCESSOR

DCIN1

DCIN2

SP-100

INTERFACE

SP-100/R

AND

PROCESSOR

MULTIPLEXER

INPUT

AMPLIFIER

ECG AMPLIFIER MK 7-2

ECG

ISOLATION

TRANSFORMER

DC - DC

CONVERTER

CABLE

TESTER

+ 12 V

PAPER

REPLACE

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Overall Functional Description

Power Supply

Mains is applied to the power supply via a mains filter, on/off switch and a voltage selection switch.
The voltage selection switch connects the supply to the relevant winding of the mains isolation
transformer. The ac voltage is then rectified to produce a resultant dc voltage of approximately
+27V. This voltage is applied to regulator circuits which generate all of the dc power supplies
required by the AT-10 electronics.

The power on/off control circuit switches the supply voltage to the regulators. The power on/off is
controlled by the following conditions:

• On signal from the keyboard

• Off signal from the Microprocessor (Off key pressed on keyboard, Reset pressed, Batt
Down (5V supply below 4.75V))

• Overcurrent condition on the +12V rail

Two 12V batteries, connected in series, directly provide the power for the thermal printer, and
provide power for the switching regulators when mains is not connected. The charge state of the
battery is monitored by a battery charge monitor circuit.

Chapter 2

Functional Overview

Processor and Memory

The AT-10 is controlled by a high speed, CMOS 68000 processor with a 16-bit data bus and 23­bit address bus. The clock speed is 16.7 MHz. The processor works in conjunction with a dedicated
gate array which is custom programmed to perform specific tasks. The working RAM memory
comprises 256 kByte of static RAM and 2MByte of dynamic RAM. The dynamic RAM holds the
ECG (or spirometry) data and other variables and an EEPROM holds the operator selectable
parameters. The unit software comprises 256kBytes of EPROM contained on the program pack. A
digital signal processing chip, also situated on the program pack, is used for real-time processing
of ECG data.

ECG

The ECG signal from the patient is low pass filtered, amplified and applied to the processor and
multiplexer circuit. The ECG Amplifier board carries out the following:

• Analog to digital conversion of the ECG signal at a sampling rate of 4kHz

• Reduction of the sampling rate to 1kHz

• Detection of pacemaker signals and

• Determination of the pulse width of a pacemaker signal

• Transmission of the processed ECG (and PM measurements and status signals) over the
opto-isolators

Page 2.7

Chapter 2
Functional Overview

Overall Functional Description (cont.)

The serial input/output is transmitted to the master CPU at 2.5 MBaud and commands are received
from the master CPU at 38.4 kBaud. To ensure absolute patient safety, an isolation transformer
galvanically isolates the AT-10 power supply from the patient.

A cable tester circuit is also incorporated on this board which allows open circuit testing of the
electrode leads. It is automatically activated when a patient lead is connected to the test point.

Keyboard

The keyboard is a matrix style circuit which is periodically scanned by the processor via the
Keyboard Interface circuit. When a key is pressed, the key information is clocked to the Processor
board for interpretation by the master CPU.

Printer Control

The Thermal Print Head is controlled by the print head controller circuit and the timer circuit. The
print head controller serialises the parallel data written by the CPU into a 16-bit FIFO register. The
timer circuit controls how long current is applied to the head, and thus the intensity of the print-out.

The printer motor speed is controlled by the master CPU via the timer circuit.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Graphics Control

The display data is generated in the graphics processor circuit under the control of the master CPU.
The graphics processor outputs a VGA standard serial video signal. The video signal is converted
to an LCD signal by the Video - LCD circuit.

Miscellaneous Inputs/Outputs

Spirometry

The serial input signal from the spirometer is connected to the interface circuit. The serial data is
clocked into a shift register in the interface circuit and, when enabled the data is presented in parallel
on the data bus for interpretation by the master CPU.

DC Inputs

The dc input connectors allow analog signals, for example from an ultra sound device or a phono
/ pulse recording unit, to be input to the AT-10. The analog inputs are converted to a digital level
and presented on the data bus. The maximum input voltage is 2.5 V p-p.

Video Connector

The video connector outputs the serial video signal generated by the graphics processor. The video
connector reflects the same data as that displayed on the LCD.

Page 2.8

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Overall Functional Description (cont.)

ERGO

The analog stress I/O circuit contains a digital to analog converter that converts load or speed
control data to an analog voltage. The elevation and speed of the treadmill is returned as an analog
value and converted to digital data for interpretation by the main CPU. When a bicycle is connected
an analog signal representing the load is sent and received.

Serial Ports

The communications controller contains USARTS which generate serial signals for the transmis­sion and reception of data. The communications driver circuit contains interface circuits to ensure
signal level compatibility with RS-232. The RS-422 connector is used when high data rates are
required or when longer cable lengths are used.

Chapter 2

Functional Overview

Page 2.9

Chapter 2
Functional Overview

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

CPU

OFF - FROM

K/B

ON - FROM

+5V

VCC

+5V

SWITCHING

REGULATOR

LOW

BATTERY

VOLTAGE

+US

ON/OFF

CONTROL

-12V

-12V
REGULATOR

12V

SWITCHING

SI2

2AF

-18V

-18V
REGULATOR

REGULATOR

OVER

+12V

CURRENT

+UB

+UBU

+3.5V

REGULATOR

+UB

BATTLC - TO

PROCESSOR

D/A

CONVERTER

UP/DOWN

CURRENT/

FREQUENCY

CONVERSION

BOARD

COUNTER

CURRENT

VOLTAGE/

MONITORING

BOARD MK 8-6

POWER SUPPLY

FILTER

FACTOR

(POWER

SWITCHING

REGULATOR

POWER

RECTIFIER

TRANS-

FORMER

ISOLATION

VOLTAGE

SELECTOR

LINE

FILTER

SWITCH

&ON/OFF

CONTROLLER)

SI1

(2 X 12V)

LEAD-ACID

BATTERIES

RECHARGABLE

10AT

24V

CURRENT

SENSE AND

RECTIFICATION

SENSE

CURRENT

BUFFER MK 8-4

LCD/KEYBOARD

BOARD

PROCESSOR

LEDB - FROM

BATT

MAINS

Power Supply - Functional Block Diagram

AT-10 (PART)

Page 2.10

FUSE

MAINS

200mAT

MAINS MODULE

INPUT

MAINS

STUD

POTENTIAL

EQUALISATION

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Power Supply

Mains is applied to the line filter via the on/off switch and two 200 mA, slow-blow fuses. The line
filter incorporates a temperature variable resistor to ensure that the current is limited at initial
switch-on. After a few seconds the resistor warms, the resistance drops and normal power is
supplied. The voltage switch ensures that the correct primary winding of the isolation transformer
is used for the mains voltage applied.

The transformed ac input is full-wave rectified by a bridge rectifier to produce a dc voltage of
approximately +22V. The rectified voltage is used by a switching regulator and filter circuit to
generate the +UB supply .

The switching regulator comprises a power factor controller chip (U1) and associated components.
The switching regulator controls a power MOS FET (Q1) which acts as a switch to regulate the
current flow in loading coil T1. Thus, via diode D4 and output filter (C89, C13 etc), the voltage of
+UB is regulated to +27V.

The pulse width set by U1, is determined by a zero current detection circuit incorporated in U1
(tapping from loading coil T1), the feedback on the current sense (via Q1 power FET), (and the
voltage feedback from +UB (via VR1) when mains is connected (Q3 is switched on). The frequency
of the switching can be between 40kHz and 500kHz.

Chapter 2

Functional Overview

An overvoltage protection circuit monitors +UB when the unit is operating form the mains and cuts
the voltage to the power supply if +UB exceeds +35V. The overvoltage protection circuit is formed
by Q30 and associated components and monitors +UB via Q3 (which is only switched on when
mains is connected to the unit). When an overvoltage is detected, the dc input voltage to the +UB
switching regulator is cut by switching off Q5.

A short circuit protection circuit formed by Q4, C3 and associated components, monitors for
undervoltage which indicates high current and a possible short circuit. If an undervoltage is detected
Q5 is switched off.

On/Off Control and Low Battery Voltage Monitoring

The supply for the +5 and ±12V regulators is controlled by an on/off control circuit. The switch of
the on/off control circuit is Q11. It is initially switched on by the ON signal from the keyboard, and
then latched by the Vcc (+5V) supply. When the OFF signal from the processor goes low, Q11 is
switched off, the power to the switching regulators is cut, and the unit is switched off.

The voltage of the battery is monitored by comparator U6C (monitoring the +US power rail). If the
voltage drops below 18.8V (battery voltage low) Q11 is switched off. In the same manner if an
overcurrent or overvoltage (+12V) is detected, Q11 is switched off via U7B.

Page 2.11

Chapter 2
Functional Overview

Power Supply (cont.)

+5V and ±12V Switching Regulators

The 5V and 12V step down switching regulators both function in the same manner. The description
given here is for the 12V regulator.

Power FETs Q9 and Q10 form a push-pull circuit which switches the supply to loading coil T2. The
power FET control circuit is formed by U6A which monitors the ac feedback (via C24) and dc
feedback (via R47) to control the switching oscillator (U5B, C17). A gate booster for the power
FETs is provided by U4 and associated components.

Secondary windings of T2 provide voltages of 13V and 25V. These are used by linear voltage
regulators to produce the regulated -12V and -18V supplies respectively.

The power supply distribution is given on the following table.

POWER SUPPLY DISTRIBUTION

Boards

+ 5 V

(VCC)

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Power Supplies

+ 12 V - 12 V -18V

+UBU

Backup

+ UB

Processor Board 3 3 3 3

LCD/Keyboard Buffer 3 3 3 3

ECG Amplifier 3 3

Interface Board 3 3

Battery Controller

The battery controller circuit measures the charge/discharge current of the battery to enable the
CPU to calculate the capacity of the battery. The battery controller circuit also controls the battery
LED to give a visual indication when the battery is charging and when the unit is using battery power.

The negative side of the battery is connected to a current sense circuit. Operational amplifier U15B
gives an indication to the counter of the current direction ie charging or discharging. Operational
amplifiers U15C and U15A form a current rectification and measurement circuit the output of which
is fed to a current frequency converter circuit. The current/frequency converter provides a
frequency output that is directly proportional to the battery charge or discharge current. The output
of the current/frequency converter clocks an up/down counter which is used to indicate the charge/
discharge current and charge/discharge time of the battery, and thus the actual capacity of the
battery.

Page 2.12

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Power Supply (cont.)

The frequency of the current/frequency converter at a charge or discharge rate of 1A is approxi­mately 31.3Hz.

The counter counts up when the battery is discharging and down when the battery is charging. The
count is converted to an analog value by D/A converter U13 for use by the CPU in determining the
charge state of the battery. When the battery is fully charged ie counter all `1´s, the DAC output
is 0V.

The counter is preset when the battery is fully charged. This is carried out by a comparator U14C
which acts as a current sense and goes high when the charging rate of the battery is less than 10mA.
Via Q23, the PRESET signal goes low and the counter is preset to all `1´s. This circuit is also used
(via Q24) to light the battery LED when the battery is charging.

Chapter 2

Functional Overview

Page 2.13

Chapter 2
Functional Overview

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

ERGO

LOAD OUT

STRESS

ANALOG

INPUT/OUTPUT

DC 2

I/O

DATA

DC 1

ECGO to ECG Amplifier

RS-232

RS-232

DATA

PORT 2

PORT 1

INTERFACE

COMMUNICATIONS

&

CONTROL

CONTROLLER

COMMUNICATIONS

RS-232

PORT 3

DUAL

PORT

RAM

PORT

RS-422

PRINTER

THERMAL

TPTH

ISYS

THERMAL

MCLK

GATING

ALBEEP

KBBEEP

TIMER

PROGRAMMABLE

PRINTER

PRINTER

THERMAL

AND CONTROL

SERIAL PRINT DATA

PRINT HEAD

CONTROLLER

TPDUR

CONTROL

VIDEO

CONNECTOR

SERIAL VIDEO DATA

SHIFT

REGISTER

LATCH

LIQUID

CRYSTAL

UPPER

LOWER

VIDEO - LCD

CONVERTER

DISPLAY

SIGNALS

CHIP SELECT

MK 8-1

BOARD

MICROPROCESSOR

AT-10 (PART)

DECODER AND

SYSTEM CONTROL LOAD IN, RPM IN

MAIN

PROCESSOR

SHIFT

REGISTER

ECG Amp

ECGI From

DATA BUS

SHIFT

REGISTER

BUS

ADDRESS

BUS

CONTROL

SP-100

CONTROL

CLOCK

REAL TIME

AND

EEPROM

STATIC RAM/

DYNAMIC RAM

PACK

PROGRAM

GRAPHICS

CONTROLLER

SYSEN

VCC

MASTER RESET

POWER ON

RESET AND

VOLTAGE SENSE

Processor - Functional Block Diagram

Page 2.14

SP-100

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Processor Board

CPU

Overall control and coordination of all circuits and all peripherals (with the exception of the paper
tray carriage motor), is by the CPU (U46) situated on the Microprocessor Board. The CPU used
is the 68000 and it works in conjunction with a dedicated gate array IC (U47). The main functions
of the gate array circuit are as follows:

• To decode the address bus (A17 to A23) and generate the chip select (CS) signals for the
memory and the peripherals.

• To generate interrupt priority signals (IPL0, IPL1, IPL2) for the main processor - the
highest priority interrupt is `7´ the lowest `1´.

• To generate the row address strobe (RAS), column address strobe (CAS) and address
multiplex control signals for the dynamic RAM.

• To synchronize the clock of the (asynchronous) ECG input signal.

Program Pack

The Program Pack comprises two EPROM chips and a DSP (digital signal processor). The DSP
is used for real time processing of the ECG signal as follows:

• QRS detection

Chapter 2

Functional Overview

• Filtering (Myogram, Mains, Baseline)

• Lead calculation ( I, II .. etc)

A 20 MHz oscillator provides the clock input for the DSP. Communication between the main CPU
and the DSP is via a 16-bit parallel port integral in the DSP.

The EPROM chips contains the AT-10 software. The EPROMs each have 256 or 512 kByte of
memory which is addressed by address lines A0 to A20 and enabled by the EPROM CS signal.

Memory

Dynamic RAM

The Dynamic RAM comprises four 1 Mbyte RAM modules. The RAM control signals are
generated by the gate array (U47). The RAM data is transparently refreshed via CAS before RAS
control protocol at approximately 1kHz. The dynamic RAM stores the following data:

• Printer pixel pattern

• Printer text data

• Stress test ECG data

• Rhythm ECG data

Static RAM and EEPROM

The two 128k RAM chips (U25 & U26) are addressed via address lines A0 to A19; they are enabled
by the CSSRAM signal. The static RAMs use the back-up power supply so that the stored data is
not lost when the unit is switched off.

Page 2.15

Chapter 2
Functional Overview

Processor Board (cont.)

The static RAM stores the following:

• Last 10 seconds of ECG data

• Patient data

The AT-10 EEPROM memory stores some user defined parameter settings and comprises a single
64k EEPROM chip (U27). It shares an enable signal (CSRTCC) with the real time clock (U30).

Communications Controller

The Communications Controller carries out the following functions:

• Controls the serial ports

• Converts the incoming analog values from the ERGO connector to digital and vice versa.

• Provides synchronization of the peripheral devices with the CPU

The communications controller comprises a single chip processor (U14) with built in RAM and
ROM to control the serial interfaces and Data I/O ports. Data between the Communications
Controller and the CPU, is via a dual port RAM (U13) which acts as a data buffer. It is selected by
the CSCC signal.

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

The inputs to the A/D converter of the communications controller processor are as follows:

• Speed/load (LOADIN)

• Elevation/RPM (RPMIN)

• Temperature signal from the thermal print head.

Communication over the RS ports is via two dual communication interface controllers. Each of the
controllers monitor two RS ports as follows:

The enable signals for the communication controllers are generated by U14 via a binary to octal
converter (U15).

U14 also outputs the TREADMILL UP and TREADMILL DOWN signals (TMUP, TMDN) to
control treadmill elevation via the Data I/O port.

Page 2.16

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Processor Board (cont.)

Stress Analog Input/Output

The analog input/output circuit comprises a digital/analog converter circuit and buffer circuits that
carry out the following functions:

• Converts the control commands for an exercise equipment (ergometer or treadmill), to the
required analog command signal - a 12-bit DAC (U40) produces the LOAD OUT signal
(ERGO 0). The output is 1V per 100 W.

• Buffers and scales the returned analog responses from the ergometer or treadmill. The
returned signals are:

• LOAD IN (ERGO 1) (also used for the treadmill speed input). The load signal is

100W = 1V,

• RPM IN (ERGO 2) (also used for the treadmill elevation input). The RPM signal

scaling is 1V = 100 RPM, the elevation angle scaling is 1V = 12°

These signals, are converted to a digital signal by the A/D converter in the Communications
Controller.

Chapter 2

Functional Overview

Thermal Print Head Controller

The thermal print head controller circuit comprises programmable generic array logic (GAL) chips
and latch buffers. Data to be printed is presented on the data bus and strobed through first in, first
out (FIFO) memories (U60 and U61) in two bytes (lower - D0 to D7, upper D8 to D15). The 10 input,
8 output GALs are programmed to serialise data from the FIFOs memories and send it in the
required format for the printer. To ensure a superior quality print the print head data is `cycled´ so
that each pulse is repeated eight times. This is carried out by FIFO memory U59.

TPD is the print head serial data signal, TPS0 and TPS1 are printer strobes, and TP clock is the 4
MHz serial data clock. The output to the printer is synchronized with the 1.9kHz clock. The
temperature control for the print head is set by the TPDUR signal (thermal print duration from the
programmable timer), which is strobed by signal TGATE (6kHz).

Programmable Printer Timer and Beeper

The timer circuit comprises U28 and U29 which decode the timing instructions from the CPU
encoded on the data bus. The timers are accessed by the CSEE signal. The timing signals produced
are as follows:

• MCLK The printer motor clock. The faster the speed of the motor the

faster the paper feed

• ISYS A general purpose timing clock of 2 kHz, used as system interrupt

(determines sampling rate, printing rate etc.)

• TPDUR The duration that the print head is heated. This is calculated by the

CPU, from the resistance of the print head and the measured
ambient temperature of the print head.

• ALBEEP, KBBEEP Audio signals for the alarm and keyboard beeper.

The timers are addressed by address lines A1 and A2 to select the required timing. The frequency
of the master clock input is 5 MHz.

Page 2.17

Chapter 2
Functional Overview

Processor Board (cont.)

Graphics Controller

A VGA standard signal (480 rows with 640 pixels/row with a horizontal sync of approximately 31.8
kHz and a vertical sync of 60 Hz), is generated by a graphics processor chip (U39) and associated
components. The video controller also generates all the necessary protocol signals (HSYNC,
VSYNC etc).

The parallel data output of the video controller is fed to two 8-bit shift registers (U33 and U34)
which together convert the 16-bit parallel output from the video controller to the required serial
video output. Two RAM chips (U31 and U32) form a latch circuit for the pixel memory and allow
picture freeze when required. The video signal to the Video/LCD Converter is gated with signal
SCINV which inverts the screen image (changes the LCD to white on black image), when set.

Certain control and enable signals from the video controller are further decoded by GAL U38.

Video - LCD Converter

The video/LCD converter chip (U74) generates all the timing and strobe signals required by the
LCD and converts the serial video signal into the correct format for display. Four upper and four
lower control and data signals are output to the LCD along with two clock signals. A working
memory for the converter chip is provided (U75).

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Power On Reset

The Power on reset circuit is formed by U54 and associated components. The circuit controls the
master reset of the CPU. This circuit has three functions as follows:

• Provides a delay on initial switch on to ensure that the power supply is fully stabilized and
to give the 200ms reset time required by the 68000 processor

• Ensures that the system is inoperative and in reset mode when the SYSEN indicates that the
Program Pack is not present

• Disables the unit if the +5V rail drops below +4.75V

Page 2.18

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Chapter 2

Functional Overview

GALVANIC ISOLATION

AT-10 (PART)

ISOLATION

TRANSFORMER

+ 12 V

DC - AC

28Vpp

POWER

ISOLATED

ECG AMPLIFIER

CONVERTER

7.5Vpp

SUPPLIES

DIGITAL/

ANALOG

CS DADY

CONVERTER

LINK

OPTO

ISOLATION

ECG I

SERIAL

TO CPU

ECG DATA

SI

SERIAL

CONVERTER

PARALLEL TO

D

A

CSGAL

SINGLE CHIP

CS DADY

ADDRESS

COMPUTER

DECODER

ECG O

CONTROL

SO

FROM CPU

- 5 Vi

- 24 Vi

- 12 Vi

+ 12 Vi

SUPPLY RAIL

STABILISATION

RECTIFICATION

28Vpp

ECG AMPLIFIER MK 7-2

GNDi

+ 5 Vi

SUPPLY RAIL

STABILISATION

BRIDGE

RECTIFICATION

7.5Vpp

DC - DC CONVERTER

CABLE

TESTER

-24V

Σ

Σ

ECGMUX

ECG

SIGNAL

MULTIPLEXER

INPUT

AMPLIFIER

FILTER AND

GAIN

SELECT

CHANNEL

CONTROL

BASELINE

DC OFFSET

PMPOS, PMNEG

TRIGGER

PACEMAKER

DETECTION AND

RA

ECG Amplifier - Functional Block Diagram

CABLE

PATIENT

CONNECTOR

Page 2.19

Chapter 2
Functional Overview

ECG Amplifier

ECG Isolated Power Supplies

The DC/DC converter circuit produces all the isolated power voltages required by the ECG
Amplifier circuit. The +12V rail from Power Supply MK 8-6 is applied to isolation transformer U2
via a pulsing circuit. The pulsing circuit comprises a 125kHz oscillator divided by two, which via
Schmitt triggers switches MOS FETs Q3 and Q4. This gives a pulsed, 180° phase shifted input on
the two primary windings of the isolation transformer.

The two secondary windings of the isolation transformer produce 28Vpp and 7.5Vpp respectively.
A Schotky diode and capacitor network produce the +12V, -12V and -24V isolated supplies. A
linear regulator (U5) generates the -5V supply from the isolated -12V supply.

The +5V isolated supply is generated from the 7.5Vpp secondary winding. A bridge rectifier
produces approximately +7V which is applied to a FET. The FET is controlled by an operational­amp and transistor circuit so that it acts as a variable resistor to stabilise and produce a +5V supply.

Servicing Note: When taking measurements always ensure that the isolated ground is

ECG Signal

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

used for reference.

The incoming ECG signals RA, LA, and C1 to C9 are 41kHz low-pass filtered and applied to non­inverting operational-amps giving a gain of 11. The signals are further low pass filtered (1.6kHz)
and amplified by 3 before being applied to the multiplexer.

The multiplexer enable signal is 4kHz with the output duration of each sampled lead approximately
20 microseconds.

The multiplexed ECG signal is base line compensated. The base line compensation is set by the
ECG processor and converted to an analog signal by a DAC (U20). The maximum compensation
is ± 300 mV. A gain control is also incorporated for the multiplexed ECG signal, and set by the
processor. This gain is selectable to 2.5, 5, or 10.

The signal is then passed to a summing circuit where the last sample value from the D/A converter
(U21) is subtracted from the present sample value. The resultant is the difference of the actual
sample and the previous sample. The resulting voltage is analog to digital converted by the ECG
processor and output to the CPU via a multiplexer and GAL circuit (U23, U26) and opto isolators.

Page 2.20

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

ECG Amplifier (cont.)

Pacemaker Trigger

The RA lead is fed, before it is filtered, to the pacemaker detection circuit. The RAPACE signal
from the patient is differentiated and fed to the ECG processor. The negative pulses (PMNEG), and
the positive pulses (PMPOS) indicate the start and end slope of the pacemaker pulse. From the
signals the CPU can calculate the timing of the pacemaker pulse for display (software option).

Chapter 2

Functional Overview

Page 2.21

Chapter 2
Functional Overview

ECG Amplifier (cont.)

Cable Tester

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

The cable tester circuit checks the resistance of an individual lead in the patient cable. The resistance
of the lead must be between 10KOhms and 1MOhms.

The cable tester comprises a 3.3kHz oscillator and comparator circuit. The oscillator is connected
to the test point and when a lead is connected to the test point, the potential on the lead (from the
input filter and amplifier circuit) alters the waveform. The waveform is rectified and, via a
comparator (U1B) lights the LED. The comparison voltage at U1B is 1.45V and the generated
waveform is at a base level of approximately -17V with an oscillation of 5V.

Page 2.22

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Interface Board

Thermal Printer Control

Chapter 2

Functional Overview

The Thermal Printer stepper motor is controlled by stepper motor controller U1. The MON signal
from the processor is the enable signal for the controller and the MCLK signal sets the speed; 209Hz
gives a paper speed of 2.5 mm/s, 2.09kHz gives a paper speed of 25 mm/s. The driver circuit
incorporates a current sense circuit. The current of the motor is approximately 100mA, depending
on the step rate set.

The printer data, the strobe and the clock signals are buffered by U5. The strobe frequencies (TPS0
and TPS1) are 2kHz, the clock (TPCLCK) is 4MHz, and the latch frequency (TPL) is 2kHz.

Because of the high power peaks drawn by the TPH, reservoir capacitors on the +24V rail ensure
a stable supply to the thermal print head (via the controller).

The paper mark detector is an opto sense circuit. The output from the detector is fed to an operational
amplifier (U4) to set the PM signal when a paper mark is detected. The input from the optocoupler
is 0.4V to 0.6V for white paper and 3.5V to 4V for black paper ie paper mark. The PM output signal
is logic 0 when a paper mark is detected.

Page 2.23

Chapter 2
Functional Overview

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 2.24

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Interface Board (cont.)

Paper Carriage Control

The paper tray carriage motor control circuit works independently from the CPU and has its own
power supply. The power supply is enabled as follows:

• AT-10 switched on Vcc (+5V) latches transistor Q9 on which latches Q7 on to

• AT-10 switched off pressing the REPLACE PAPER key sets signal EJCT to

+Uop is regulated by U4C to generate the +5V supply for the paper carriage motor control circuit
(5Vpd).

Chapter 2

Functional Overview

switch +UB and generate +Uop.

GND and switches transistor Q7 on to generate +Uop from
the +UB supply. Q7 is latched on by Q9 which is switched
on by the DIR.IN signal high. When the tray has returned,
the DIR.IN signal goes to ground which switches Q9 and
Q7 off. This cuts the +Uop rail and switches off the power
supply.

Note that when the AT-10 is switched on the power supply
remains on via Q9 held on from Vcc.

Extend Paper Tray

The 5Vpd voltage initially sets a delay and timing circuit formed by U6C, U6D and associated
components. This sets the ENABLE and INIT signals to flip-flops U7A and U7B so that the circuit
is in a known state. Pressing the REPLACE PAPER key sets the EJECT signal to the flip-flops, via
Q8. The flip-flops enable the motor control chip U8 and set the direction of the 24V dual polarity
motor (GO IN, GO OUT signals). The motor controller incorporates an `H´ bridge current sense
circuit to detect when the paper tray is fully extended. When the paper tray is fully extended the
current increases, the motor controller detects this and sets the sense line which, via comparator
U4D is fed back via a delay circuit, resets the flip-flops and stops the motor. A delay circuit (C34)
prevents the motor being stopped prematurely during the power surge when the motor is initially
activated.

Retract Paper Tray

When the paper tray is extended, pressing the REPLACE PAPER key switches off transistor Q8
and activates the EJECT signal. This produces a clock input to the flip-flops and activates the GO
IN signal to the motor controller. In the same manner as when the paper tray is being extended, the
current sense circuit stops the motor when the paper tray has fully returned.

The flip-flop control circuit monitors the printer motor via the MON signal, and the paper tray motor
via the Stop signal (paper tray motor active). This ensures that the circuit is disabled if the
REPLACE PAPER key is pressed when either the printer motor, or paper tray motors are active.

Page 2.25

Chapter 2
Functional Overview

SCHILLER AT-10 ECG and Spirometry Unit

SERVICE HANDBOOK Issue c April 2002

Page 2.26

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Introduction 3.2
Test Equipment 3.3
Fault Diagnosis 3.4

AT-10 Initial Fault Diagnosis Chart (Sheet 1) 3.5
AT-10 Initial Fault Diagnosis Chart (Sheet 2) 3.6
AT-10 Fault Diagnosis Chart (Sheet A - Power Problems) 3.7
AT-10 Fault Diagnosis Chart (Sheet B - Power Problems) 3.8
AT-10 Fault Diagnosis Chart (Sheet C - General Problems) 3.9
AT-10 Fault Diagnosis Chart (Sheet D - Printer Problems) 3.10
AT-10 Fault Diagnosis Chart (Sheet E - Auto Mode Problems) 3.11
AT-10 Fault Diagnosis Chart (Sheet F - Exercise Mode Problems) 3.12
AT-10 Fault Diagnosis Chart (Sheet G - Spirometry Problems) 3.13
AT-10 Fault Diagnosis Chart (Sheet H - Communication Problems) 3.14

Chapter 3

Fault Diagnosis

Chapter 3

Fault Diagnosis

Contents

Page 3.1

Chapter 3
Fault Diagnosis

Introduction

The purpose of this chapter is to provide fault-finding procedures that will quickly and efficiently
identify a fault on an AT-10 to a specific module. The fault-finding procedures are designed so that
test equipment is kept to a minimum.

An initial fault diagnosis chart is provided detailing all the general fault indications that may occur.
When this is followed it will indicate the module where the fault lies or specify a further fault-finding
procedure. When more than one module is stated, the first module given is the one most likely to
contain the fault. If the fault is not found on the first module, the other modules should be checked
in the order given.

If the initial fault-finding chart does not indicate the area where the fault exists, re-check all the
settings and parameters that have been entered (for the particular task that fails). If these are correct,
check the software. If this is correct suspect external connections.

If a key operation or menu selection is required when carrying out the functional checks after
replacement, the key sequence required is given in parenthesis ‘<>´. The character(s) given in
parenthesis is the actual character(s) printed on the key. When a key sequence is provided it must
be followed in the order given. For example the key sequence to give the Macro screen is:

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

<FNCT> <2> <ENTER>

This requires that the Function key on the keypad is pressed, followed by the `2´ key followed by
the Return (or Enter) key.

Page 3.2

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Test Equipment

The following proprietary and dedicated test equipment is the minimum that is required to fault find
and carry out any board checks and adjustments, on the AT-10.

The list of proprietary equipment is not comprehensive. Recommendations of suitable proprietary
test equipment can be obtained from the Schiller Service Department.

Dedicated Test Equipment

• RS Test Cable Assembly required for the RS self test

In addition to the above a Schiller patient cable (Schiller Number 2.400011) is required when
carrying out simulated ECG tests.

Proprietary Test Equipment/Tools

• ECG Emulator, eg Phantom 320*

• Oscilloscope

• Digital Multimeter*

• Stabilised Power Supply

Chapter 3

Fault Diagnosis

• Standard tool kit with a selection of cross-bladed, flat-bladed and posi-drive screwdrivers,
Pliers and general tools*

• Soldering Iron

• VGA Monitor

* Indicates Essential Equipment for basic AT-10 fault finding

Special Tools / Equipment

The following table lists all the special tools and equipment that may be required when fault finding
or carrying out certain maintenance procedures on the AT-10.

Page 3.3

Chapter 3
Fault Diagnosis

Fault Diagnosis

Use the fault finding charts and procedures on the following pages to indicate a faulty area or
module. In most cases the fault finding charts should indicate the most likely faulty area.

When a possible faulty module is indicated by the fault finding charts, the module must be replaced.
When a module has been replaced specific test parameters and setting-up of the module may be
applicable. The removal and replacement instructions for all replaceable modules, along with any
set-up or check procedures required, are given in Chapter 4.

MAINS POWER IS PRESENT WHEN THE UNIT COVER IS REMOVED. CERTAIN CHECKS
AND ADJUSTMENTS CAN ONLY BE CARRIED OUT WITH THE TOP ASSEMBLY
REMOVED AND MAINS CONNECTED. WHEN CARRYING OUT THESE PROCEDURES
BEWARE THAT POTENTIALLY LETHAL VOLTAGES ARE PRESENT.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

WARNINGS

CAUTIONS

THE AT-10 CONTAINS STATIC SENSITIVE CMOS COMPONENTS; OBSERVE ANTI­STATIC PRECAUTIONS. ALWAYS PLACE THE UNIT ON AN EARTHED ANTI-STATIC
MAT WHEN CARRYING OUT ANY MAINTENANCE PROCEDURES. PERSONNEL MUST
BE EARTHED WHEN HANDLING ANY BOARDS OR COMPONENTS. ALWAYS USE AN
ANTI-STATIC BAG WHEN TRANSPORTING BOARDS OR COMPONENTS

CARE MUST BE TAKEN WHEN REMOVING AND REPLACING CONNECTORS. NEVER
USE FORCE. NEVER STRAIN THE CABLE ASSEMBLIES.

Page 3.4

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

CONNECT MAINS TO THE

UNIT AND SWITCH ON

Chapter 3

Fault Diagnosis

IS THE GREEN MAINS

LED LIT?

YES

NO

DISCONNECT THE MAINS
SUPPLY AND CHECK THE

MAINS FUSE (IN THE MAINS

ASSEMBLY AND CHECK

MODULE)

FUSE OK?

YES

REMOVE THE TOP

FUSES SI 1 AND SI 2

FUSE SI 2 OK?

YES

NO

NO

ENSURE THAT THE

VOLTAGE SELECTOR IS

CORRECTLY SET. REPLACE

THE MAINS FUSE AND

SWITCH THE MAINS ON

INVESTIGATE THE REASON

FOR THE RUPTURED FUSE

REPLACE THE FUSE AND

SWITCH THE UNIT ON

FUSE OK?

FUSE SI 2 OK?

YES

GO TO FAULT DIAGNOSIS

NO

NO

(SHEET A - POWER PRO-

BLEMS)

REPLACE THE POWER

SUPPLY BOARD

PRESS THE AT-10

<ON> KEY

DOES THE LCD LIGHT?

YES

A

SHEET

TWO

YES

INVESTIGATE THE REASON

FOR THE RUPTURED FUSE

CHECK THE BATTERIES,

THE BATTERY LEADS AND

THE BATTERY

CONNECTORS FOR SHORT

CIRCUITS. REPLACE FUSE

AND SWITCH ON. IF THE

FUSE IS STILL RUPTURING

REPLACE THE POWER

SUPPLY BOARD

Note: The removal and replacement

instructions and the location of
all boards, cable assemblies

GO TO FAULT DIAGNOSIS

(SHEET B - POWER PRO-

NO

GO TO FAULT DIAGNOSIS

(SHEET C - GENERAL PRO-

FUSE SI 1 OK?

YES

BLEMS)

BLEMS)

NO

and connectors are given in
Chapter 4.

AT-10 Initial Fault Diagnosis Chart (Sheet 1)

Page 3.5

Chapter 3
Fault Diagnosis

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

A

FROM

SHEET

ONE

IS THE

DATA BOX

(DISPLAYED IN THE

TOP RIGHT HAND
CORNER OF LCD)

VISIBLE ?

YES

CHECK CABLE ASSEMBLY

BETWEEN PROCESSOR

BOARD AND POWER

SUPPLY(P1). CHECK CABLE

ASSEMBLY BETWEEN

POWER SUPPLY AND K/B/

LCD BUFFER. REPLACE:

1. K/B/LCD BUFFER BOARD

ARE STRAIGHT

LINE ECG TRACES

DISPLAYED ON THE

LCD ?

YES

PRESS

<PRINT SCREEN>. DOES

THE PRINTER FUNCTION

AT ALL?

YES

CHECK THE LCD CONTRAST

CONTROL ON THE RIGHT-

HAND PANEL OF THE UNIT.

NO

CONNECT AN EXTERNAL

VGA MONITOR TO THE VI-

DEO CONNECTOR ON THE

SIDE PANEL.

MONITOR

DISPLAYS DATA ?

YES

2. LCD

NO

NO

REPLACE THE

PROCESSOR BOARD

CHECK CABLE ASSEMBLY
BETWEEN POWER SUPPLY

AND INTERFACE BOARD

(P20) . CHECK CABLE

ASSEMBLIES FROM INTER-

FACE BOARD TO PRINTER.

1. PROCESSOR BOARD

3. THERMAL PRINTER

NO

REPLACE THE

PROCESSOR BOARD AND

PROGRAM PACK

REPLACE:

2. I/F BOARD

ARE ECG TRACES

DISPLAYED ON

THE LCD?

YES

PRESS THE <AUTO START>

KEY AND WAIT FOR THE

PRINT-OUT

DOES THE PRINT-

OUT GIVE THE ECG

TRACES AND PATIENT

DATA?

YES

DOES THE EXERCISE

TEST FUNCTION?

YES

DOES THE SPIROMETRY

TEST FUNCTION?

GO TO FAULT DIAGNOSIS

NO

NO

CHART (SHEET B - POWER

PROBLEMS). IF THE POWER

SUPPLY IS OK REPLACE:

1. ECG AMPLIFIER BOARD

2. PROCESSOR BOARD

NO

GO TO FAULT DIAGNOSIS

CHART (SHEET E - AUTO

GO TO FAULT DIAGNOSIS

EXERCISE MODE PRO-

NO

GO TO FAULT DIAGNOSIS

SPIROMETRY PROBLEMS)

MODE PROBLEMS)

CHART( SHEET F -

BLEMS)

CHART (SHEET G -

GOOD? IS THE PRINTER

CONNECT A PATIENT

SIMULATOR TO THE ECG

CONNECTOR AND SWITCH

Page 3.6

PRINTER MOTOR

FUNCTIONED?

YES

IS THE

PRINT QUALITY

FUNCTIONING

CORRECTLY?

YES

ON

GO TO FAULT DIAGNOSIS

NO

CHART (SHEET B - POWER

PROBLEMS). IF THE POWER

SUPPLY IS OK CHECK THE

PRINTER MOTOR.

DO THE RS INTERFACES

FUNCTION?

NO

GO TO FAULT DIAGNOSIS

CHART (SHEET D - PRINTER

PROBLEMS)

DOES THE PAPER

TRAY EJECTION WORK

CORRECTLY?

YES

CHECK ALL PARAMETER

SETTINGS. CHECK THE

TEST SCREEN AND ENSURE

THAT PARAMETERS ARE IN

TOLERANCE (PARAGRAPH

6). CONTACT SCHILLER IF

FAULT CANNOT BE FOUND

AT-10 Initial Fault Diagnosis Chart (Sheet 2)

YES

YES

NO

NO

GO TO FAULT DIAGNOSIS

CHART (SHEET H -

COMMUNICATION PRO-

BLEMS)

ENSURE THAT THE

BATTERIES ARE FULLY

CHARGED. REMOVE THE

PAPER TRAY AND ENSURE

THAT THE MECHANICAL

WORMDRIVE IS NOT

JAMMED. CHECK THE DC

MOTOR FOR OPEN CIRCUIT.

CHANGE THE INTERFACE

BOARD

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

MAINS FUSE RUPTURED

REMOVE THE TOP ASSEMBLY .

VISUALLY INSPECT ALL CABLE

ASSEMBLIES AND CONNECTORS.
ENSURE THAT ALL CONNECTORS
ARE SECURE. LOOK IN THE AREA

OF THE TRANSFORMER AND
MAINS INPUT FOR SIGNS OF

BURNING OR SCORCHING.

Chapter 3

Fault Diagnosis

ARE ALL THE CABLE

ASSEMBLIES AND
CONNECTORS OK?

YES

DISCONNECT THE FLYING

LEADS FROM THE MAINS

TRANSFORMER TO THE

POWER SUPPLY. REPLACE

THE MAINS FUSE AND

SWITCH ON.

IS THE MAINS FUSE

OK?

YES

NO

NO

RECTIFY THE CAUSE OF THE

FAULTY COMPONENT(S).

INTERNAL CABLES TO THE

REPLACE THE MAINS FUSE

PROBLEM. REPLACE

DISCONNECT THE

MAINS ASSEMBLY.

AND SWITCH ON.

IS THE MAINS FUSE

OK?

YES

NO

SHORT CIRCUIT IN THE

MAINS ASSEMBLY.

REPLACE THE MAINS

ASSEMBLY

SHORT CIRCUIT IN THE

POWER SUPPLY. REPLACE

THE POWER SUPPLY

SHORT CIRCUIT IN THE
MAINS TRANSFORMER.

REPLACE THE MAINS

TRANSFORMER

Note: The removal and replacement

instructions and the location of
all boards, cable assemblies
and connectors are given in
Chapter 4.

AT-10 Fault Diagnosis Chart (Sheet A - Power Problems)

Page 3.7

Chapter 3
Fault Diagnosis

REMOVE THE TOP

ASSEMBLY . VISUALLY

INSPECT ALL CABLE

ASSEMBLIES AND

CONNECTORS. ENSURE

THAT ALL CONNECTORS
ARE SECURE. CHECK THE
CABLE ASSEMBLY FROM

THE POWER SUPPLY TO

THE TOP ASSEMBLY.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

ARE ALL THE CABLE

ASSEMBLIES AND

CONNECTORS OK?

YES

DISCONNECT P27A AND

P27B FROM THE MAINS

TRANSFORMER TO THE

POWER SUPPLY. CONNECT

A DVM ACROSS THE MAINS

TRANSFORMER.

IS THE AC VOLTAGE

READING APPROXI-

MATELY 18 V?

YES

NO

NO

RECTIFY THE CAUSE OF THE

FAULTY COMPONENT(S).

DISCONNECT THE MAINS.

REMOVE THE CABLES TO

THE MAINS ASSEMBLY.

SWITCH ON THE MAINS AND

MEASURE FOR AC MAINS

ACROSS PINS 1 AND 3, AND

PROBLEM. REPLACE

PINS 2 AND 4

IS THE AC MAINS

SUPPLY GOOD?

YES

NO

REPLACE THE MAINS

ASSEMBLY

Mains

Assembly

Page 3.8

POSSIBLE FAULT IN THE
POWER SUPPLY. CHECK ALL
POWER RAILS AS DETAILED

IN CHAPTER 5.

ARE ALL POWER

SUPPLIES OK?

YES

NO

REPLACE THE MAINS

TRANSFORMER

REPLACE THE POWER

SUPPLY

Note: The removal and replacement

REPLACE THE CABLE

ASSEMBLY BETWEEN THE

POWER SUPPLY AND THE

LCD/K/B BUFFER BOARD

(BASE ASSEMBLY TO TOP

ASSEMBLY). REPLACE THE

LCD/K/B BUFFER BOARD.

REPLACE THE LCD.

instructions and the location of
all boards, cable assemblies
and connectors are given in
Chapter 4.

AT-10 Fault Diagnosis Chart (Sheet B - Power Problems)

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

ENSURE THAT THE PROGRAM PACK IS

INSERTED. REMOVE THE TOP ASSEMBLY.

ASSEMBLIES AND CONNECTORS. ENSURE

THAT ALL CONNECTORS ARE SECURE.

Chapter 3

Fault Diagnosis

VISUALLY INSPECT ALL CABLE

ARE ALL THE CABLE

ASSEMBLIES AND

CONNECTORS OK?

YES

CHECK ALL POWER

RAILS AS DETAILED IN

CHAPTER 5

ARE ALL POWER

SUPPLIES OK?

YES

CHECK THE LCD

CONTRAST CONTROL.

CONNECT AN EXTERNAL

VGA MONITOR TO THE

VIDEO CONNECTOR

NO

NO

RECTIFY THE CAUSE OF THE

PROBLEM. REPLACE

FAULTY COMPONENT(S).

REPLACE THE POWER

SUPPLY

MONITOR DISPLAYS

DATA?

YES

CHECK THE CABLE ASSEMBLY BETWEEN THE

POWER SUPPLY AND THE LCD/K/B BUFFER

BOARD (BOTTOM ASSEMBLY TO TOP

ASSEMBLY). CHECK THE CABLE ASSEMBLY

BETWEEN THE PROCESSOR BOARD AND THE

POWER SUPPLY (P1). REPLACE THE LCD/K/B

BUFFER BOARD. REPLACE THE LCD. REPLACE

THE VIDEO/LCD CONVERTER (PROCESSOR

BOARD)

NO

REPLACE THE PROCESSOR

BOARD AND PROGRAM

PACK

Note: The removal and replacement

instructions and the location of
all boards, cable assemblies
and connectors are given in
Chapter 4.

AT-10 Fault Diagnosis Chart (Sheet C - General Problems)

Page 3.9

Chapter 3
Fault Diagnosis

CHECK THAT THE CORRECT

PRINTER RESISTANCE IS

STORED IN MEMORY AND THAT

THE PRINT HEAD AMBIENT

TEMPERATURE IS CORRECT AS

DETAILED IN CHAPTER 5.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

WERE THE READINGS

CORRECT?

YES

ENSURE THAT GOOD
QUALITY, FRESH PAPER IS
INSTALLED IN THE PAPER

TRAY. CHANGE IF

NECESSARY.

DOES THE

PAPER JAM OR NOT

STOP AT THE CORRECT

POSITION ?

YES

CHECK AND ADJUST THE
PAPER MARK DETECTOR

AND CURRENT LIMITER

THRESHOLDS AS DETAILED

IN CHAPTER 5.

NO

NO

WAS THE PRINTER

RESISTANCE

CORRECT?

YES

PROBLEM READING

AMBIENT TEMPERATURE.

REPLACE:

1. THERMAL PRINT HEAD

2. PROCESSOR BOARD

CARRY OUT THE PRINTER

CHECK DETAILED IN

CHAPTER 5. REPLACE THE

THERMAL PRINT HEAD IF

NECESSARY

NO

ENTER THE CORRECT

PRINTER RESISTANCE

DETAILED IN

CHAPTER 5

Page 3.10

DOES THE PROBLEM

STILL EXIST?

YES

REPLACE:

1. PROCESSOR BOARD

2. INTERFACE BOARD

3. THERMAL PRINTER

Note: The removal and replacement

instructions and the location of
all boards, cable assemblies
and connectors are given in
Chapter 4.

AT-10 Fault Diagnosis Chart (Sheet D - Printer Problems)

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

CHECK ALL PATIENT LEADS.

ENSURE THAT ALL

CONNECTIONS ARE SECURE.

ENTER THE ELECTRODE

TEST SCREEN AS DETAILED

IN CHAPTER 5.

Chapter 3

Fault Diagnosis

ARE THE PATIENT

LEADS ALL WITHIN

TOLERANCE?

YES

PRESS <ECG>, <5> (ECG

SETTINGS), <6> (FURTHER
SETTINGS),<1> (NUMBER OF
COPIES). ENSURE THAT THE

NUMBER OF COPIES IS NOT

SET TO ´0`.

NUMBER OF COPIES

SET TO ´0`?

YES

SET THE NUMBER OF

COPIES TO REQUIRED

NUMBER

NO

NO

CHECK THE FAULTY LEAD.

REPLACE THE PATIENT

CABLE IF NECESSARY.

CHANGE THE PROGRAM

PACK. CHANGE THE
PROCESSOR BOARD.

AT-10 Fault Diagnosis Chart (Sheet E - Auto Mode Problems)

Page 3.11

Chapter 3
Fault Diagnosis

CHECK THAT THE CABLE ASSEMBLY TO THE

STRESS TEST EQUIPMENT IS CORRECTLY AND

FIRMLY CONNECTED. THAT IS:

- RS CONTROLLED STRESS
EQUIPMENT TO RS PORT 2

- ANALOGUE CONTROLLED STRESS
TEST EQUIPMENT TO THE STRESS
CONNECTOR.

- BLOOD PRESSURE EQUIPMENT TO
RS PORT 1 (IF USED)

NB ENSURE THAT THE STRESS

TEST PARAMETERS ARE
CORRECTLY SET (SEE CHAP­TER 1 OR AT-10 OPERATING
HANDBOOK)

NB ENSURE THAT THE STRESS

TEST EQUIPMENT IS
FUNCTIONING COR­RECTLY

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

IS A DIGITAL, RS

CONTROLLED STRESS

TEST EQUIPMENT

USED?

YES

NO

PROBLEMS

WITH BLOOD PRESSURE

MEASUREMENT?

YES

CARRY OUT THE RS

INTERFACE SELF TEST

DETAILED IN CHAPTER 5

DOES THE PROBLEM

STILL EXIST?

YES

NO

REPLACE:

1. PROGRAM PACK

2. PROCESSOR BOARD

Page 3.12

AT-10 Fault Diagnosis Chart (Sheet F - Exercise Mode Problems)

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

CHECK THE FILTER IN THE

FLOW SENSOR. ENSURE THAT

IT IS NOT BLOCKED AND THAT

IT IS CLEAN. REPLACE IF

NECESSARY AS DETAILED IN

CHAPTER 5.

CHECK ALL SPIROMETRY

CABLING. ENSURE THAT
ALL CONNECTIONS ARE

SECURE.

Chapter 3

Fault Diagnosis

FLOW SENSOR AND

CABLE OK?

YES

ENTER THE SPIROMETRY
MENU (<SPIRO>. ENSURE

THAT THE CALIBRATION IS

CORRECT AND THAT ALL
SETTINGS ARE CORRECT.

CAN THE CALIBRA-

TION PROCEDURE BE

CARRIED OUT?

YES

POSSIBLE OPERATOR

ERROR.

NO

NO

REPLACE THE FLOW

SENSOR.

CHECK FLOW SENSOR.

CHANGE:

1. PROGRAM PACK

2. PROCESSOR BOARD

Note: The removal and replacement

instructions and the location of
all boards, cable assemblies
and connectors are given in
Chapter 4.

AT-10 Fault Diagnosis Chart (Sheet G - Spirometry Problems)

Page 3.13

Chapter 3
Fault Diagnosis

PRESS <STORAGE> <1> (SETTINGS)

<3> (CONFIG OF TRANSMISSION).

CHECK THAT ALL SETTINGS( LINE

OR MODEM, RECORD OR BLOCK)

ARE CORRECT FOR THE

APPLICATION.

PRESS <STORAGE> <2> (TEST

MODE). CHECK THAT ALL

SETTINGS( PARITY, STOP BIT)

AND THE BAUD RATE ARE THE

SAME IN BOTH DEVICES.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

ARE THE SETTINGS

COMPATIBLE IN BOTH

THE TRANSMITTING

AND RECEIVING

DEVICES?

YES

CARRY OUT THE RS SELF

TEST PROCEDURE

DETAILED IN CHAPTER 5.

TEST PASSED?

YES

POSSIBLE OPERATOR

ERROR.

CHECK ALL CABLE

ASSEMBLIES. REPLACE IF

NECESSARY

NO

NO

PROGRAM ALL SETTINGS TO

ENSURE COMPATIBILITY

BETWEEN THE COMMUNI-

CATING DEVICES

1. CHECK THE +12V AND -12V
SUPPLY VOLTAGES AS

DETAILED IN CHAPTER 5.

2. CHANGE THE PROCESSOR
BOARD

3. CHANGE THE RS

CONNECTOR ASSEMBLY

Note: The removal and replacement

instructions and the location of
all boards, cable assemblies
and connectors are given in
Chapter 4.

Page 3.14

AT-10 Fault Diagnosis Chart (Sheet H - Communication (RS) Problems)

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Introduction 4.3
Base Assembly 4.4
Top Assembly 4.9
Removal and Replacement 4.11
Opening the Case 4.13

Top Assembly Removal 4.13
Top Assembly Replacement 4.14
Functional Check After Assembling the AT-10 4.14

Power Supply Board MK 8-6 4.17

Power Supply Board Removal 4.17
Power Supply Board Replacement 4.17
Checks and Tests after Power Supply Board Replacement 4.17
Checking the Power Supplies 4.18

Lead-acid Batteries 4.20

Battery Removal 4.20
Battery Replacement 4.21
Checks and Tests After Battery Replacement 4.21

Interface Board MK 8-5 4.22

Interface Board Removal 4.22
Interface Board Replacement 4.23
Checks and Tests After Interface Board Replacement 4.23

Paper Tray Assembly 4.24

Paper Tray Removal 4.24
Paper Tray Replacement 4.25
Checks and Tests after Paper Tray Assembly Replacement 4.25

Microprocessor Board 4.26

Microprocessor Board Removal 4.27
Microprocessor Board Replacement 4.27
Checks and Tests After Microprocessor Board Replacement 4.28

Chapter 4

Physical Overview & Module Replacement

Chapter 4

Physical Overview &

Module Replacement

Contents

Page 4.1

Chapter 4
Physical Overview & Module Replacement

Program Pack and Software Modules 4.29

Program Pack (and program EPROM and DSP) Removal 4.30
Program Pack (and program EPROM and DSP) Replacement 4.30
Checks and Tests After Program Replacement 4.30

ECG Amplifier Board 4.31

ECG Amplifier Board Removal 4.31
ECG Amplifier Board Replacement 4.31
Checks and Tests after Replacement 4.32

Mains Assembly 4.33

Mains Assembly Removal 4.33
Mains Assembly Replacement 4.34
Checks and Tests after Replacement 4.34

Mains Transformer 4.35

Mains Transformer Removal 4.35
Mains Transformer Replacement 4.35
Checks and Tests after Replacement 4.35

LCD / Keyboard Buffer MK 8-4 4.36

LCD/Keyboard Buffer Removal 4.38
LCD/Keyboard Buffer Replacement 4.38
Checks after Replacement 4.38

LCD 4.39

LCD Removal 4.40
LCD Replacement 4.40
Checks after LCD Replacement 4.41

Thermal Printer and Print Head 4.42

Thermal Printer Removal 4.42
Print Head Removal 4.42
Print Head Replacement 4.42
Thermal Printer Replacement 4.44
Checks, Tests and Adjustments after Printer Replacement 4.44

Keyboard 4.45

Keyboard Removal 4.45
Keyboard Replacement 4.46
Checks after Replacement 4.46

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Page 4.2

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Introduction

The AT-10 comprises two main assemblies as follows:

• The Base Assembly

• The Top Assembly

The Base Assembly contains most of the AT-10 electronics, and all external connectors. The Top
Assembly houses the keyboard and the LCD display. The two assemblies are moulded to fit together
and are secured with captive screws. Electrical connection between the two assemblies is achieved
with a ribbon cable assembly.

Because of the plastic construction, threaded metal inserts are used for all screw fixings in the unit.

Chapter 4

Physical Overview & Module Replacement

Page 4.3

Chapter 4
Physical Overview & Module Replacement

Base Assembly

The base assembly comprises a moulded plastic tray onto which is mounted the following:

• Mains Isolation Transformer

• Two Lead-Acid Batteries

• Power Supply PCB MK 8-6

• ECG Amplifier PCB MK 7-2

• Interface Board MK 8-5

• Microprocessor Board MK 8-1

• Program Pack MK 8-11

• Thermal Printer

• Paper Tray Assembly with Carriage Motor

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

The Microprocessor board and the ECG Amplifier are secured to moulded supports on the bottom
of tray. The Power Supply is mounted on four spacers above the Microprocessor board and the
Interface board and the thermal printer are mounted on the metal paper tray framework. Electrical
connection between all boards is achieved with ribbon cable assemblies or with flying leads.

The Mains Connector and Switch assembly is secured to the Back Panel with spring loaded clips.
The Mains Transformer is secured to the tray with a centre screw. Electrical connection between
the Power Supply board, the Transformer, the Batteries, and the Mains Connector and Switch
assembly, is achieved by flying leads.

The Program Pack is inserted via a cut-out in the side panel under the paper tray. It is mounted in
slides and connects directly with the Processor Board. One captive screw secures the Program Pack
in position.

Cut-outs in the back and side panels are provided for external connectors. The Video, DC1, DC2,
and the Spiro (SP-110) connectors are all mounted directly on the Microprocessor board. The
Patient connector is mounted directly on the ECG Amplifier. All other connectors are mounted on
dedicated mounting plates.

Page 4.4

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Chapter 4

Physical Overview & Module Replacement

Base Assembly - Top Assembly Removed

Page 4.5

Chapter 4
Physical Overview & Module Replacement

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Page 4.6

Base Assembly - Paper Carriage extended and Power Supply Board,

Interface Board and Battery Removed

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Base Assembly (cont.)

The metal paper tray framework allows the paper tray to be withdrawn. The dual rotation paper
carriage motor turns a worm drive to slide the paper tray in or out.

Chapter 4

Physical Overview & Module Replacement

Page 4.7

Chapter 4
Physical Overview & Module Replacement

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Page 4.8

LCD / Keyboard Assembly

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Top Assembly

The Top Assembly is manufactured from moulded plastic and comprises a Main Housing with a
hinged LCD Assembly.

Secured in the Main Housing is the LCD / Keyboard Buffer MK8-4 and the Keyboard MK 8-3. Both
of these boards are secured with double sided tape. Electrical connection between the modules is
achieved with ribbon cable assemblies or with flying leads.

Chapter 4

Physical Overview & Module Replacement

Page 4.9

Chapter 4
Physical Overview & Module Replacement

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

REMOVE TOP ASSEMBLY

POWER SUPPLY

BOARD

PROCESSOR

BOARD

IN BASE ASSEMBLY ACCESS

PAPER TRAY

ASSEMBLY AND

MOTOR

ECG AMPLIFIER

TO:

INTERFACE

BOARD

CONNECTOR

PANELS

THERMAL

PRINTER

MAINS

MODULE

BATTERIES

MAINS

TRANSFORMER

Page 4.10

REMOVE TOP ASSEMBLY

IN TOP ASSEMBLY ACCESS

TO:

LCD / KEYBOARD

BUFFER

KEYBOARD

Note: Access to the Program Pack is gained via the left-hand Side Panel under the paper tray

Access to the mains fuse and the voltage selector is from the back panel (Mains Module).

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Removal and Replacement

Introduction

This Chapter provides the procedures required to carry out the removal and replacement of all
modules that are spared at service level. The instructions given in this chapter are autonomous, with
each module containing the following:

• The pre-requisites that must be fulfilled before removal of the module

• Tools and equipment that are required to remove and replace the module and to carry out
the functional checks and adjustments.

• Removal Procedures

• Replacement Procedures

• Checks and Tests that must be carried out after replacement.

Any adjustments, jumper settings, special checks or functional procedures that are required during
a procedure, are detailed in the relevant step.

In-text diagrams support the text where required and provide location details of connectors, test
points and adjustment potentiometers.

Chapter 4

Physical Overview & Module Replacement

Specific warnings and cautions are given where applicable. Warnings indicate potential danger
could cause personal injury. Cautions indicate areas that could cause damage to the equipment .

If a key operation or menu selection is required, the key sequence required is given in parenthesis `<>´. The
character (or character string) given in parenthesis is the actual character that is printed on the key. When a
key sequence is provided it must be followed in the order given. For example the key sequence to display the
macro screen is as follows:

<FNCT> <2> <ENTER>

This requires that the function key on the keypad is pressed, followed by the 2 key, followed by the
return key (Enter).

Page 4.11

Chapter 4
Physical Overview & Module Replacement

Safety Notes

BEFORE COMMENCING ANY REMOVAL OR REPLACEMENT PROCEDURES ENSURE
THAT THE MAINS POWER SUPPLY IS SWITCHED OFF AND THAT THE MAINS CABLE
IS REMOVED.

CERTAIN CHECKS AND ADJUSTMENTS CAN ONLY BE CARRIED OUT WITH THE TOP
ASSEMBLY REMOVED AND WITH MAINS CONNECTED. WHEN CARRYING OUT
THESE PROCEDURES BEWARE THAT POTENTIALLY LETHAL VOLTAGES ARE
PRESENT.

THE AT-10 CONTAINS STATIC SENSITIVE CMOS COMPONENTS; OBSERVE ANTI­STATIC PRECAUTIONS:

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

WARNINGS

CAUTIONS

• WHEN CARRYING OUT ANY MAINTENANCE PROCEDURES ALWAYS PLACE THE
UNIT ON AN EARTHED ANTI-STATIC MAT.

• PERSONAL MUST BE EARTHED WHEN HANDLING ANY BOARDS OR
COMPONENTS

• ALWAYS USE AN ANTI-STATIC BAG WHEN TRANSPORTING BOARDS OR
COMPONENTS

THE UNIT IS SUSCEPTIBLE TO ABRASION DAMAGE. TO PREVENT SCRATCHING,
ALWAYS PLACE THE UNIT ON A SOFT, NON-ABRASIVE CLOTH WHEN CARRYING
OUT MAINTENANCE PROCEDURES

TAKE CARE NOT TO PLACE ANY STRAIN ON THE CONNECTING RIBBON CABLE
WHEN REMOVING THE TOP ASSEMBLY . ENSURE THAT THE CABLE ASSEMBLY IS
NOT CRIMPED OR TWISTED AND THAT THE TOP ASSEMBLY IS NOT PLACED ON THE
CABLE ASSEMBLY.

CARE MUST BE TAKEN WHEN REMOVING AND REPLACING CONNECTORS. NEVER
USE FORCE. NEVER STRAIN THE CABLE ASSEMBLIES.

THE PROCEDURAL STEPS GIVEN FOR EACH MODULE MUST BE FOLLOWED IN THE
ORDER GIVEN.

Page 4.12

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Opening the Case

Pre-requisites

• The unit must be placed on an anti-static mat and anti-static precautions observed when any
maintenance is carried out on the AT-10. The room temperature should be between 18 and
28 degrees.

• Mains supply is required to carry out the unit functional test after assembly.

• THE WARNINGS AND CAUTIONS AT THE BEGINNING OF THE CHAPTER MUST
BE OBSERVED.

Tools

• Posi-drive screwdriver

Test Equipment

The following test equipment is required to carry out the functional test after unit assembly

• Schiller Patient Cable

• Patient Simulator eg phantom 320.

Chapter 4

Physical Overview & Module Replacement

• RS Test Cable (supplied by Schiller)

Top Assembly Removal

The Top Assembly is mounted on the Base Assembly and is secured to the Base Assembly with four
screws and washers; access to the screws is gained from the underside of the unit. To remove the
Top Assembly, proceed as follows:

1. Remove all cable assemblies connected to the side and rear panels. Ensure that the mains
cable is removed.

2. Taking care to secure the hinged LCD module so that it cannot swing open, turn the unit up­side-down and rest on a soft cloth.

3. Unscrew the six retaining screws and washers situated in the extreme corners and edges of
the unit, indicated by an arrow.

4. Grasping the top and bottom of the unit to ensure that the two assemblies cannot part,
carefully return the unit to the standing position.

5. Gently lift the Top Assembly sufficiently to gain access to the interconnecting cable, and
disconnect the connector from the Power Supply Board.

6. Gently lift the Top Assembly away from the Base Assembly and place on a soft cloth.

Page 4.13

Chapter 4
Physical Overview & Module Replacement

Opening the Case (cont.)

Top Assembly Replacement

To replace the Top Assembly proceed as follows:

1. Check that all boards and components are firmly secured. Check for loose screws. Ensure
that no screws or foreign bodies are loose in the bottom of the case.

2. Inspect all the internal cable assemblies and ensure that they are in good condition and that
no visible damage can be seen. Ensure that no cable assemblies are strained, crushed or
caught.

3. Ensure that all connectors are firmly home.

4. Position the Top Assembly adjacent to the Base Assembly and without straining the ribbon
cable, plug in the interconnecting cable from the Top Assembly to the Power Supply (P12).

Note: It may be necessary to tilt the Top Assembly for the cable assemblies to reach.

5. Carefully position the Top Assembly on the Base Assembly.

6. Grasping the two assemblies to ensure that they cannot part, carefully turn the unit up-side­down and replace the six securing screws and washers in the extreme corners and edges of
the unit. Return the unit to the upright position.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Functional Check After Assembling the AT-10

The procedure detailed here is a general confidence check in the unit after an internal module or
board has been replaced. It is not a full functional test but is intended to identify any faults that may
be present after the unit has been reassembled. If any check fails go to Fault Diagnosis Chapter 4.
To carry out the general confidence check proceed as follows:

1. Ensure that the voltage selector on the back panel is set for the required voltage and connect
mains to the unit. Switch on the mains and ensure that the green mains LED on the hinged
LCD Assembly, lights.

2. Switch the unit on by pressing the <ON> key on the Keyboard. Ensure that the LCD lights
and that for a few seconds the test screen is displayed at the bottom of the screen. When the
test screen disappears, check that straight line traces are displayed for the selected leads and
that the information box in the top right-hand corner of the display, is present.

3. Press <FNCT> <2> <2> and enter the time and date details. Press <ESC> when complete.
Ensure that the correct date and time is displayed on the screen.

4. Connect the ECG phantom to the ECG connector on the side panel and switch the phantom
on. Ensure that a good ECG trace is displayed on the screen.

5. Press the <PRINT SCREEN> key and ensure that the print-out is accurate and of good
quality. Press <MAN START> and ensure that the print-out is accurate and of good quality.

6. Press the <AUTO START> key and wait approximately 10 seconds for the print-out to
commence. Ensure that the print-out is accurate and of good quality.

7. Connect the RS test cable to RS-232 ports 1, 2 and 3 on the back panel and carry out the RS
transmission test as detailed in Chapter 5.

Page 4.14

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Opening the Case (cont.)

8. Press the <PATIENT DATA> key and systematically press the keys:
<QWERTZUIOP>, <ENTER>, <1234567890>

Ensure that the entered data is presented on the screen as entered. Press <ESC> to exit from
the patient data display.

9. Press the <BEGIN> key and ensure that the AT-10 indicates that an exercise test has

commenced. Press the <STOP> key and ensure that a print-out is given.

10.Enter the required static parameter values. Store the entered parameter values by pressing

Note: Details of all parameters and parameter values are provided in the AT-10 Operating

Manual.

11.If a module has been replaced carry out the checks and tests detailed in the relative

Paragraph (if not already carried out). Switch the unit off and leave connected to the mains
supply for 15 hours to fully charge the battery. Ensure that the Battery LED is extinguished
when the battery is fully charged.

Chapter 4

Physical Overview & Module Replacement

<FNCT <2> <5>.

12.Disconnect the mains power supply and leave the unit for 24 hours. Switch the unit on and

check that the battery LED lights. Ensure that all static parameters have been remembered.
Leave the unit switched on for 45 minutes (without using the printer) and check that the
battery LED does not start to flash in that time.

Page 4.15

Chapter 4
Physical Overview & Module Replacement

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Page 4.16

Power Supply Board MK 8-6

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Power Supply Board MK 8-6

The Power Supply board is positioned on four spacers above the Processor board.

Pre-requisites

• The Warnings and Cautions at the beginning of the Chapter must be observed.

• The Top Assembly must be removed as detailed in Paragraph 2 and all external cable

assemblies disconnected.

Tools and Equipment

• Cross-Bladed screwdriver

• Small flat-bladed screwdriver

• Digital Voltmeter

In addition if the Power Supply board is checked in isolation, a Power Supply capable of supplying
up to 30V, is required.

Parts

• Power Supply MK 8-6. Part number as detailed in Chapter 6.

Chapter 4

Physical Overview & Module Replacement

Power Supply Board Removal

WARNING

ENSURE THAT THE MAINS CABLE IS DISCONNECTED BEFORE COMMENCING

To remove the Power Supply board proceed as follows:

1. Disconnect the flying leads to the mains transformer and to the batteries. Disconnect P20 to

the Interface board, P1 to the Microprocessor and the GND guard P17. (P12 to the LCD/
Keyboard Buffer MK 8-4 will already be removed).

2. Unscrew the four screws securing the board to the spacers and remove the board

Power Supply Board Replacement

To replace the Power Supply proceed as follows:

1. Position the board on the spacers and secure with the four securing screws.

2. Connect the Mains Transformer leads and the battery leads. Connect P1, P20 and P17

(GND).

Checks and Tests after Power Supply Board Replacement

After assembly, connect the mains supply to the unit and ensure that the green mains supply LED
is lit. Switch the unit on and ensure that the LCD is lit and that meaningful data is displayed. Press
the <PRINT SCREEN> key. Ensure that the printer functions.

Page 4.17

Chapter 4
Physical Overview & Module Replacement

Power Supply Board MK 8-6 (cont.)

Check that the battery charge monitor circuit is functioning as follows:

1. Switch the unit off but leave the mains connected. Leave the battery to charge for 10 hours.
Check that the battery light flashes when the battery is charging and extinguishes when the
battery is fully charged (after a maximum time of 15 hours).

2. Disconnect the mains and run the unit on battery power for 60 minutes (without using the
printer). Check that:

• the battery LED lights when running on battery power

• the battery LED flashes when the battery capacity is low

• the unit switches off when the battery capacity falls below a preset value

Note: Control of the Battery LED is from the CPU which uses the counter signal

(BATTLC ) to calculate the charge state of the battery. If the Battery LED is not
giving the expected indications, the fault may lie on the Processor board (or P1
connector). The signal to control the battery LED is LEDB.

The nominal battery capacity at which the Battery Low is active (LED flashing) is
25%. The nominal voltage at which the Battery down signal is active and the unit
switches off, is 21V.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Checking the Power Supplies

The power supply voltages can be checked without the AT-10 being assembled. However the Power
Supply board is easily accessible and it is usually easier to check the power supplies with the unit
assembled and the Top Assembly positioned by the side. If the board is to be checked in isolation
a latch circuit must be manually set to switch on the power supply ( equivalent to pressing the <ON>
key).

Test points are provided on the Power Supply board for measurement of all power rails.

Individual adjustment is not possible for any of the voltage rails except +UB (from which all other
supplies are generated and the batteries are charged). Note that +UB can only be adjusted with mains
connected.

On Signal Simulation

If the Power Supply board is checked in isolation the on line must be connected to GND to latch
the power supply on. To simulate the on signal, proceed as follows:

Note: The on simulation signal is only required when the ON key on the keypad, cannot be

used to switch the power supply on, that is when P12 to the Top Assembly is
disconnected.

1. Connect power to the Power Supply board as follows:

• If the unit is assembled, use either mains (via the mains transformer) or two fully

charged batteries connected to the battery connectors

Page 4.18

• If the unit is not assembled, connect a power supply to the battery connectors on the

Power Supply board. Connect the positive to pin 1 of plug P25, and the negative to
pin 2 of plug P26. Set the Power Supply to 24V.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Power Supply Board MK 8-6 (cont.)

2. Using a suitable lead, connect GND to Plug P12 pin 25, and hold for 2 seconds. The power
supply will now be latched on and all generated power supplies can be checked for the
correct voltage.

Note: To switch the power supply off, connect 0V to P1 pin 50.

+UB Adjustment

This adjustment sets the voltage supplied from the switching regulator on the mains power factor
controller circuit. To adjust this voltage the unit must be assembled and mains connected.

WARNING

Chapter 4

Physical Overview & Module Replacement

LETHAL VOLTAGES ARE PRESENT WHEN CHECKING AND ADJUSTING THE POWER
SUPPLY. DO NOT LET CONCENTRATION LAPSE. EXERCISE GREAT CARE WHEN
TAKING MEASUREMENTS.

To check and adjust +UB supply proceed as follows:

1. Connect mains power to the unit and switch on by pressing the <ON> key on the keyboard.

2. Measure the voltage at P25 pin 1. Adjust VR1 to achieve a voltage of +27V ±200mV.

Power Rail Measurement

No adjustment is possible for any of the power rails. To check the power rail voltages go on the
relevant test point (component layout given at the end of this book) and measure with a DVM. If
any of the values are out of tolerance first ensure that +UB voltage is correct. If this is correct the
power supply must be changed.

Page 4.19

Chapter 4
Physical Overview & Module Replacement

Lead-acid Batteries

Two batteries are installed in the AT-10. They are self contained with integral leads and connectors.

Pre-requisites

• The Warnings and Cautions at the beginning of the Chapter must be observed.

• The Top Assembly must be removed as detailed in Paragraph 2 and all external cable
assemblies disconnected.

Parts

The part numbers of all replaceable items are given in Chapter 6.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Battery Removal

THE MAINS SUPPLY MUST BE DISCONNECTED DURING THIS PROCEDURE

To remove the battery proceed as follows:

1. Ensure that the unit is switched off and that the mains is disconnected. Remove all cable

2. Disconnect the battery connectors from the Power Supply board and remove the batteries.

Page 4.20

WARNING

assemblies connected to the front and rear panels.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Lead-acid Batteries (cont.)

Battery Replacement

To replace the battery position the battery and connect the leads to the battery connector on the
Power Supply.

Note: Red lead is the + battery terminal

Black lead is the - battery terminal

Checks and Tests After Battery Replacement

To ensure that the battery and the battery recharging circuit are functioning after battery replacement,
proceed as follows:

1. Connect mains to the unit and ensure that the green mains and the yellow battery indicators,
next to the display, are lit. Charge the battery for approximately 15 hours.

2. Ensure that the Battery indicator is extinguished after 15 hours (battery fully charged).

3. So that the capacity of the newly installed battery is calculated correctly by the processor,
run the unit on battery power until the battery is fully discharged and the unit switches off.
Repeat this process two times. This ensures that the correct capacity of the battery is
registered by the processor. The calculated value of the battery capacity can be seen by
pressing:

Chapter 4

Physical Overview & Module Replacement

<ECG> <6> (electrode test) <ENTER> <ENTER>

The B CAPACITY indication displays the calculated battery capacity. See Chapter 5 for
further details.

4. Program all static settings, for example time and date, which will have been lost when the
battery was disconnected.

Page 4.21

Chapter 4
Physical Overview & Module Replacement

Interface Board MK 8-5

Pre-requisites

• The Warnings and Cautions at the beginning of the Chapter must be observed.

• The Top Assembly must be removed as detailed in Paragraph 2 and all external cable
assemblies disconnected.

Tools

• Cross-bladed screwdriver

• Small flat-bladed screwdriver

Parts

• Interface Board MK 8-5. Part number as detailed in Chapter 6.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Page 4.22

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Interface Board MK 8-5 (cont.)

Interface Board Removal

To remove the Interface Board disconnect all connectors, unscrew the four screws securing the
board to the Paper Tray Assembly, and lift the board away from the Paper Tray Assembly.

Interface Board Replacement

The replace the Bus Interface position the board on the Paper Tray Assembly and secure using the
four captive screws. Reconnect all connectors to the Thermal Printer and the Power Supply.

Checks and Tests After Interface Board Replacement

The paper mark detection offset must be checked. To set the paper mark threshold proceed as
follows:

1. Connect a digital voltmeter across the P4 connector (test point 1).

2. Switch the unit on and adjust VR1 to obtain a reading as follows:

• > 3.5V when the black paper mark is under the paper mark detector

Chapter 4

Physical Overview & Module Replacement

• 0.4 to 0.5V when there is no paper mark under the detector ie white paper

NB IF THE DETECTION DOES NOT RECOGNISE THE PAPER MARK AFTER

ADJUSTMENT, ENSURE THAT THE PAPER MARK WINDOW IS CLEAN.

3. Carry out the printer check to ensure that the board is functioning correctly . Enter the
following key sequence:

<ECG> <6> (electrode test) <P>

A print-out of a series of diagonal lines will be given. Examine the print-out and ensure that
all the lines are even and uninterrupted. Ensure that the complete paper is covered with
close diagonal lines and that no blocks of plain paper are present. Any faulty print-head
pixels will be seen as a horizontal white line. Examine the print-out for evenness of print.

Note: Unevenness of print or faulty individual pixels indicates a problem with the printer

or printer alignment. If a complete block is left unprinted it additionally indicates
that the Interface board could be faulty or the fault lies with the printer data control
circuits on the Processor board.

Page 4.23

Chapter 4
Physical Overview & Module Replacement

Paper Tray Assembly

The Paper Tray Assembly comprises a metal framework onto which is mounted the paper tray and
motor, the thermal printer and the interface board. It is positioned above the Processor board and
is mounted on four spacers.

Pre-requisites

• The Warnings and Cautions at the beginning of the Chapter must be observed.

• The Top Assembly must be removed as detailed in Paragraph 2 and all external cable
assemblies disconnected.

Tools

• Cross-Bladed Screwdriver

• Flat-Bladed Screwdriver

Parts

• The part number for the Paper Tray Assembly, complete with the DC motor is given in
Chapter 6.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

WARNING

ENSURE THAT THE MAINS CABLE IS DISCONNECTED BEFORE COMMENCING

Paper Tray Removal

To remove the Paper Tray Assembly proceed as follows:

1. Remove P20 on the Power Supply.

2. Carefully turn the unit upside down and rest it on a soft cloth. Remove the four screws
retaining the paper tray assembly.

3. Hold the two parts together and turn them right side up. Watch for screws falling out !

4. Taking care not to damage the printer motor gently ease the complete Paper Tray Assembly
away from the unit.

Page 4.24

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Paper Tray Assembly (cont.)

Paper Tray Replacement

To replace the Paper Tray Assembly proceed as follow:

1. Gently ease the assembly in position on the four spacers above the Processor board.

2. Hold the two parts firmly together and turn upside down. Secure the four screws retaining
the Paper Tray Assembly to the Base Assembly.

3. Turn right side up and replace P20 on the Power Supply.

4. Replace the Top Assembly as detailed earlier.

Checks and Tests after Paper Tray Assembly Replacement

After assembly connect mains to the unit and ensure that the green power LED lights. Press the
<REPLACE PAPER> key and ensure that the paper tray retracts smoothly. Check the printer by
entering enter the following key sequence:

<ECG> <6> (electrode test) <P>

A series of diagonal line will be printed. Ensure that the print-out is even.

Chapter 4

Physical Overview & Module Replacement

Page 4.25

Chapter 4
Physical Overview & Module Replacement

Microprocessor Board

Pre-requisites

• The Warnings and Cautions at the beginning of the Chapter must be observed.

• The Top Assembly must be removed as detailed in Paragraph 2 and all external cable
assemblies disconnected.

• The Power Supply board and the paper tray assembly must be removed before removing the
Processor board.

Tools

• Cross-Bladed screwdriver

Parts

• Microprocessor Board MK 8-1. Part number as detailed in Chapter 6.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Page 4.26

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Microprocessor Board (cont.)

Microprocessor Board Removal

The Microprocessor board is secured to the Base Assembly with screws. To remove the Microproc­essor Board proceed as follows:

CAUTION

THE MICROPROCESSOR BOARD CONTAINS CMOS COMPONENTS. ANTI-STATIC
PRECAUTIONS MUST BE OBSERVED AT ALL TIMES.

1. Remove the Top Assembly as detailed above.

2. Remove the Power Supply board

3. Remove the Paper Tray Assembly as detailed above.

4. Remove the Program Pack

5. Disconnect the following connectors from the Microprocessor board:

• P4 A and B to the ERGO and DATA I/O connectors on the back panel

Chapter 4

Physical Overview & Module Replacement

• P6 to the ECG Amplifier

• P2 to the RS connectors on the Back Panel

• P11 to the Beeper Connector

• GND

6. Unscrew and remove the six Microprocessor board securing screws (one under the program
pack) and the four spacers for the Power Supply board and remove the Microprocessor
Board.

Note: The Program Pack is mounted in slides on the Microprocessor board and connects

directly with it. Removal and replacement instructions for the Program Pack are
provided in Paragraph 8.

Microprocessor Board Replacement

To replace the Microprocessor board proceed as follows:

1. Position the Microprocessor board in the Base Assembly and secure with the ten securing
screws.

2. Reconnect the following connectors to the Microprocessor board:

• P4 A and B to the ERGO and DATA I/O connectors on the back panel

• P6 to the ECG Amplifier

• P2 to the RS connectors on the Back Panel

• P11 to the Beeper Connector

• GND

Page 4.27

Chapter 4
Physical Overview & Module Replacement

Microprocessor Board (cont.)

3. Slide in, and secure the Program Pack as detailed below

4. Replace the Paper Tray Assembly as detailed above.

5. Replace the Power Supply board as detailed above.

6. Replace the Top Assembly.

Checks and Tests After Microprocessor Board Replacement

When the unit is reassembled after Microprocessor board replacement, the functional check
detailed on page 14 must be carried out to ensure the integrity of the assembled unit.

The capacity of the battery is calculated and stored by the processor for reference. To recalculate
and store the correct battery capacity proceed as follows:

1. Fully charge the battery by leaving the unit connected to the mains for 15 hours.

2. Run the unit on battery power until the battery is fully discharged and the unit switches off.

3. Repeat this process two times.

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

The value of the battery capacity calculated (and stored) by the processor, can be seen by pressing:

<ECG> <6> (electrode test) <ENTER> <ENTER>

The B CAPACITY indication displays the calculated battery capacity. See Chapter 5 for further
details.

Program all static settings.

Page 4.28

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Program Pack and Software Modules

Pre-requisites

Tools

• Cross-Bladed screwdriver

• Special chip removal tool type AMP.

Parts

• Program Pack with the correct software installed, or the software EEPROM or DSP
modules. Part numbers as detailed in Chapter 6.

Chapter 4

Physical Overview & Module Replacement

Note: The EEPROM software is available in various languages indicated by the label on

the EEPROM. The second letter in brackets indicates the language as follows:

E - English

D - German

S - Swedish

I - Italian

F - French

P - Spanish

Page 4.29

Chapter 4
Physical Overview & Module Replacement

SCHILLER AT-10 ECG and Spirometry Unit
SERVICE HANDBOOK Issue c April 2002

Program Pack and Software Modules (cont.)

Program Pack (and program EEPROM and DSP) Removal

The Program Pack is mounted in slides secured on the Processor board. Access to the Program Pack
is gained from the side panel under the Paper Tray.

CAUTION

THE PROGRAM PACK CONTAINS STATIC SENSITIVE CMOS COMPONENTS. OBSERVE
ANTI-STATIC PRECAUTIONS.

Use the attached handle to gently ease the Program Pack away from the connector.

To remove an EEPROM or DSP chip from the board, use the special chip removal tool to gently
and evenly ease the chip away from the socket.

Program Pack (and program EEPROM and DSP) Replacement

Note: The software version of a program EEPROM or DSP chip is written on the label

attached to the chip. Before replacing a program chip ensure that it is the correct
software version for the application.

To replace an EEPROM or DSP chip, position it above the socket so that the chip alignment notch
is matched with the socket alignment notch. Gently and firmly push home until retained by the
connector.

To replace the Program Pack, slide the pack in the board guides and gently and firmly push home.

Checks and Tests After Program Replacement

1. Switch the unit on by pressing the <ON> key on the Keyboard for approximately a second.
Ensure that the LCD lights and that for a few seconds the test screen is displayed at the
bottom of the screen. When the test screen disappears, check that straight line traces are
displayed for the selected leads and that the information box in the top right-hand corner of
the display, is present.

2. Switch the unit on and check that the correct software version, as stated on the label is
installed. To do this press the key sequence:

<ECG> <6> (electrode test) <.> (period)

The software version is displayed on the LCD. (See Chapter 5 for software details).

3. Carry out the AT-10 functional check detailed on page 14.

Page 4.30