Model 7300 Service Manual Rev 03

Service Policy

Respironics Novametrix, Inc. provides 24-hour a day access to technical support through its Technical Support Department in Wallingford, Connecticut, and company Service Representatives located throughout the United States. (Outside the U.S., primary technical support is handled through our qualified international sales and service distributors.) Respironics Novametrix, Inc. will provide Warranty Service support within 48 hours of receiving a request for assistance. Contact the Technical Support Department by telephone toll free at 800-243-3444, or 203-265-7701; by facsimile at 203-284-0753; or, by e-mail at [email protected]. After hours telephone support requests (before 8:00 AM and after 5:00 PM Eastern Time) will be responded to promptly by the Technical Support on-call staff. After hours facsimile and e-mail requests will be answered the next business day. It is suggested that any person calling in for technical support have the equipment available for product identification and preliminary troubleshooting. Respironics Novametrix, Inc. reserves the right to repair or replace any product found to be defective during the warranty period. Repair may be provided in the form of replacement exchange parts or accessories, on-site technical repair assistance or complete system exchanges. Repairs provided due to product abuse or misuse will be considered “non-warranty” and invoiced at the prevailing service rate. Replaced or exchanged materials are expected to be returned to Novametrix within 10 days in order to avoid (additional) charges. Return materials should be cleaned as necessary and sent directly to Novametrix using the return paperwork and shipping label(s) provided (Transferring return materials to a local sales or dealer representatives does not absolve you of your return responsibility.). Respironics Novametrix, Inc. manufactures equipment that is generally field serviceable. When repair parts are provided, the recipient can call Technical Support for parts replacement assistance and repair assurance. In the event a replacement part requires increased technical capability, Technical Support may request Biomedical assistance, provide on-site technical support or complete replacement equipment. If the customer requires the return of their original product, the exchange material will be considered “loaner material” and exchanged again after the customer equipment is repaired. Respironics Novametrix, Inc. promotes customer participation in warranty repairs, should they become necessary. A longer useful product life, and quicker, more costeffective maintenance and repair cycles-both during and after the warranty period, are benefits of a smooth transition into self-maintenance. The Technical Support Department can provide technical product support at a level appropriate to your protocol and budget requirements. Please contact Technical Support for information on these additional programs and services: • Focus Series Technical Training Seminars • Test Equipment and Test Kits • Service Contract / Parts Insurance Plans • On-Site Technical Support • “Demand Services” including: Flat rate parts exchange Flat rate return for repair Time and material, Full warranty, discounted replacement sensors.

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Warranty

Equipment manufactured or distributed by Respironics Novametrix, Inc., is fully guaranteed, covering materials and workmanship, for a period of one year from the date of shipment, except for certain disposable products and products with stated guarantees other than one year. Respironics Novametrix, Inc. reserves the right to perform guarantee service(s) at its factory, at an authorized repair station, or at the customer’s installation. Novametrix’ obligations under this guarantee are limited to repairs, or at Novametrix’ option, replacement of any defective parts of our equipment, except fuses, batteries, and calibration gasses, without charge, if said defects occur during normal service. Claims for damages during shipment must be filed promptly with the transportation company. All correspondence concerning the equipment must specify both the model name and number, and the serial number as it appears on the equipment. Improper use, mishandling, tampering with, or operation of the equipment without following specific operating instructions will void this guarantee and release Novametrix from any further guarantee obligations.

Service Department For factory repair service: Call toll free: 1-800-243-3444 To Call Direct: (203) 265-7701 Facsimile (203) 284-0753 http://www.novametrix.com [email protected]

Caution: Federal (U.S.A.) law restricts this device to sale, distribution, or use by or on the order of a licensed medical practitioner. Copyright ©2003. Respironics Novametrix, Inc., 5 Technology Drive, Wallingford, Connecticut, 06492. All rights reserved.

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Table of Contents Safety ... 1 Warnings ... 1 Cautions ... 2 Notes ... 3 Introduction ... 5 About this manual ... 5 Front and Rear Illustrations ... 5 NICO® Monitor Technical Description ... 6 Manufacturing Quality & Safety ... 6 Declaration of Conformity with European Union Directive ... 6 Trademarks and Patents ... 6 Manual Revision History ... 6 Theory of Operation ... 7 NICO® Model 7300 Non-Invasive Cardiac Output Monitor ... 7 Digital Board 2763 ... 7 Microprocessor ... 7 Background Mode Debugging and Application Development ... 11 System Memory ... 11 User Interface Control Circuitry ... 12 Real Time Clock, Power on RESET Generation and Glue Logic ... 12 Power Supply 2764 (Power Supply and Communications) ... 13 Serial Communications UART ... 13 CO2 Pulser Source Drive ... 15 CAPNOSTAT Case and Detector Heater Control ... 16 Saturation LED Power Generation and LED Drive ... 17 Power Supply and Voltage Reference Generation ... 17 Logic and Input / Output Signal Control ... 20 Analog Board 2765-01 ... 20 CAPNOSTAT Interface ... 20 CO2 Input Signal Path ... 20 CO2 Case and Detector Heater Regulation ... 21 Flow Zeroing and Patient Line Purging ... 22 Flow Circuitry ... 22 Barometric and Airway Pressure ... 23 Patient Airway Adapter Type Sensing ... 23 NICO® Sensor Rebreathing Valve Control ... 24 Saturation Input Signal Path and Signal Conversion ... 24 Functional Testing ... 25 Equipment Required ... 25 Functional Test ... 25 Determining Torr Value ... 27 Accuracy Tests ... 31 Equipment Required ... 31 CO2 Testing ... 31 SpO2 Testing ... 32 Flow Testing ... 33 Time / Date Setting ... 33

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Electronic Tests ... 35 Equipment Required ... 35 Power Supply ... 36 Voltage Checks ... 37 CO2 Testing ... 39 SpO2 Testing ... 39 Flow, Barometric Pressure and Rebreathe Valve Testing ... 40 Serial / Analog Testing ... 41 Safety Testing ... 42 Maintenance ... 43 General ... 43 Cleaning and Sterilization ... 43 Single Patient Use NICO® Sensor ... 43 CO2/Flow Sensors ... 43 CAPNOSTAT® CO2 Sensor ... 43 NICO® Monitor ... 43 SpO2 Finger Sensor ... 43 SpO2 Y-Sensor ... 44 SpO2 Tapes and Foam Wraps ... 44 Ear Clip ... 44 Monitor Maintenance Schedules ... 44 Battery Maintenance ... 44 Disassembly ... 44 Equipment Required ... 44 Disassembling Unit ... 45 Reassembling Unit ... 48 Replacing the Internal Battery ... 48 Mains Voltage Configuration ... 49 Fuse Replacement ... 50 Software Update Instructions ... 50 Equipment Required ... 50 Setup ... 50 Procedure ... 51 Troubleshooting ... 53 Screen Messages ... 53 Additional troubleshooting ... 60 Specifications ... 61 General ... 61 Cardiac Output ... 61 CO2 ... 61 Flow ... 62 SpO2 ... 62 Monitor Specifications ... 62 RS232 Communications ... 63 Analog Specifications ... 63 NICO® Accessories ... 65 Parts Lists ... 67 9226-00 Non-Invasive Cardiac Output Monitor, Model 7300 ... 67 9226-01 Main Assy ... 67 2763-01 Digital Board Assy ... 69 2764-01 Power Board Assy ... 70 2765-01 Analog Board Assy ... 74 2766-01 CO2 Input Board Assy ... 77 9392-01 Pump W Rsvr Assy ... 78 Test Fixtures ... 79 5776-48 TB1265 Adapter Cable ... 79 5693-48 Current Limit Test Jack ... 80 6573-48 Shorted Saturation Test Jack ... 81

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9636-48 Differential Test Jack ... 82 9638-48 Common Mode Test Jack ... 82 9645-48 Plug Test Fixture ... 83 9635-14, 9635-48 Optical Encoder Test Jacks ... 83 9695-48 Leak Test Adapter ... 84 Drawings ... 85

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Safety For maximum patient and operator safety, observe the following warnings, cautions and notes.

1.1

Warnings WARNING:

!

Indicates a potentially harmful condition that can lead to personal injury.

• Explosion Hazard: Do not use the NICO® monitor in the presence of flammable anesthetics. Use of this instrument in such an environment may present an explosion hazard. • Electrical Shock Hazard: Always turn the NICO monitor off before cleaning it. Do not use with a damaged external power source. Refer servicing to qualified service personnel. • Connect the AC Mains power cord to a properly grounded hospital-grade outlet. The NICO monitor should be connected to the same electrical circuit as other equipment in use on the patient. Outlets of the same circuit can be identified by members of the hospital’s engineering department. • Failure of Operation: If the monitor fails to respond as described, do not use it until the situation has been corrected by qualified personnel. • Reuse (disassembly, cleaning, disinfecting, resterilizing, etc.) of the CO2, CO2/ Flow and NICO Sensors may compromise device functionality and system performance and cause a potential patient hazard. Performance is not guaranteed if a sensor is reused. • Inspect the CO2, CO2/Flow, SpO2 and NICO Sensors prior to use. • Do not use if they appear to be damaged or broken. • Do not attempt to rotate the NICO Sensor in the breathing circuit by grasping the pneumatic tubes exiting the flow sensor. • Do not apply excessive tension to any cable or pneumatic tubing. • Periodically inspect sensor tubing lines for kinks. • Replace the CO2/Flow or NICO Sensor if excessive moisture or secretions are observed in the tubing. • The NICO monitor automatically identifies the type of sensor (small, standard or large NICO Sensor, or neonatal, pediatric or adult CO2/Flow sensor) when it is connected. If a sensor identification message is not displayed when a sensor is first connected, DO NOT use the sensor. If the condition persists, refer the monitor to qualified service personnel.

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1 Safety

Cautions

• Do not use the NICO monitor if it is unable to properly identify a CO2/Flow sensor or a NICO Sensor. If the condition persists, refer the monitor to qualified service personnel. • In the event the message NICO SENSOR FAILURE is displayed, remove the NICO Sensor from the patient circuit. • The CO2/Flow or NICO Sensor connector should be properly inserted into the front panel receptacle prior to connecting a sensor to the breathing circuit, in order to avoid a circuit leak, or occlusion of sensor tubing. • NICO Sensors increases airway deadspace by 35 cc (minimum). At low tidal volumes, compensatory changes to ventilation protocol should be considered. • NICO Sensors are not for pediatric use. • Patient Safety: Care should be exercised to assure continued peripheral perfusion distal to the SpO2 sensor site after application. • Inspect the SpO2 sensor site for adequate circulation at least once every four hours. • When applying sensors take note of patient’s physiological condition. For example, burn patients may exhibit more sensitivity to heat and pressure and therefore additional consideration such as more frequent site checks may be appropriate. • Periodically check sensors and tubing for excessive moisture or secretion build up. Although the NICO monitor automatically purges the lines, excessive moisture or secretions may still remain. • While using the sensors, a system leak, such as that caused by uncuffed endotracheal tubes or a damaged sensor may significantly affect flow related readings. These include flow, volume, pressure, deadspace, CO2 production and other respiratory mechanics parameters. • Do not position sensor cables or tubing in any manner that may cause entanglement or strangulation. • The NICO monitor is not intended to be used as an apnea monitor. • The NICO monitor has no protection against the ingress of water.

1.2

Cautions CAUTION:

!

Indicates a condition that may lead to equipment damage or malfunction.

• Use only Novametrix approved sensors and accessories with the NICO monitor. • Do not operate the NICO monitor when it is wet due to spills or condensation. • Do not operate the product if it appears to have been dropped or damaged. • Never sterilize or immerse the monitor in liquids. • Do not sterilize or immerse sensors except as directed in this manual. • No tension should be applied to any sensor cable or tubing. • To avoid the effects of excessive moisture in the NICO Sensor, insert it in the ventilator circuit with the pneumatic tubes upright. Excessive moisture in the NICO Sensor may affect the accuracy of the measurements. • To avoid the effects of excessive moisture in the measurement circuit, insert the CO2/Flow sensor in the ventilator circuit with the tubes upright. Improper placement may result in erroneous data.

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Safety 1

Notes

• Excessive moisture in the CO2/Flow sensor tubing may affect the accuracy of the measurements. • It is recommended that CO2/Flow or NICO Sensors be removed from the circuit whenever an aerosolized medication is delivered. These medications may contaminate the sensor windows, causing the sensor to fail prematurely. • Operate the monitor at temperatures between 10 to +40° C (50 to 104° F), 10-95% R.H. non-condensing. • Avoid storing the monitor at temperatures less than -10° C or greater than +55° C (<14° F or >131° F) 10-95% R.H. non-condensing • Observe precautions for electrostatic discharge (ESD) and electromagnetic interference (EMI) to and from other equipment. • Where electromagnetic devices (i.e., electrocautery) are used, patient monitoring may be interrupted due to electromagnetic interference. Electromagnetic fields up to 3 V/m will not adversely affect system performance. • Caution: Federal (U.S.A.) law restricts this device to sale, distribution, or use by or on the order of a licensed medical practitioner.

1.3

Notes NOTE: A point of particular interest or emphasis intended to provide more efficient or convenient operation.

• In order to ensure proper monitoring of oxygenation and ventilation: • The use of pulse oximetry is recommended during monitoring with the NICO system. • Setting of ETCO2 and SpO2 alert limits is recommended. • A “NO RESPIRATION” alert is not generated when both the CAPNOSTAT® CO2 sensor and the NICO Sensor or CO2/Flow sensor are disconnected from the NICO monitor. • Be certain that the monitor is not in Demo mode while monitoring. Demo mode can be identified by the flashing DEMO MODE label in the General Message area of the display. To exit Demo mode and return to normal monitoring mode, turn the power off and back on. • The NICO monitor contains no user serviceable parts. Refer servicing to qualified service personnel. A technical Service Manual is available for use by technical personnel. • Do not attach an SpO2 sensor distal to a blood pressure cuff. Valid data cannot be processed when the cuff is inflated. Attach the sensor to the limb opposite to the site used for the blood pressure cuff. • This product and its accessories which have patient contact are free of latex. • The NICO monitor is Year 2000 compliant. • Data Validity: Inaccurate SpO2 and Pulse Rate values may be caused by: • Incorrect application or use of a sensor • Significant levels of dysfunctional hemoglobin; carboxyhemoglobin or methemoglobin • Significant levels of indocyanine green, methylene blue, or other intravascular dyes • Exposure to excessive illumination such as surgical lamps-especially ones with a xenon light source, or direct sunlight

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1 Safety

Notes

• Excessive patient movement • Venous pulsations • Electrosurgical interference • Use of an IABP. • The NICO monitor provides C.O. measurements when the following conditions are met: • The NICO Sensor assembly is properly installed in the patient’s breathing circuit. • Valid flow and CO2 signals are detected with no significant signal artifact. • VCO2 is greater than 20 mL/min. • ETCO2 is between 15 and 85 mmHg (2.0 - 11.5 kPa or %) during baseline • ETCO2 is between 15 and 100 mmHg (2.0 - 13.5 kPa or %) during rebreathing • The tidal volume is greater than 200ml (small and standard sizes) • The tidal volume is greater than 400 ml (large size). • The respiratory rate is between 3 and 60 br/min. • The STOP/CONTINUE REBREATHING key is not illuminated. • The NICO cycle is not paused by the monitor for any other reason (displayed in the C.O. message area). • When a new CAPNOSTAT® CO2 sensor is attached to the monitor, or is moved from one monitor to another, it must be zeroed before use. • After the life cycle of the equipment and accessories has been met, disposal should be accomplished following national and local requirements.

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2 2.1

Introduction About this manual This document contains information which is proprietary and the property of Respironics Novametrix, Inc., and may not be reproduced, stored in a retrieval system, translated, transcribed, or transmitted, in any form, or by any means, without the prior explicit written permission of Respironics Novametrix, Inc. Novametrix reserves the right to change specifications without notice.

2.2

Front and Rear Illustrations

Front panel keys

Knob Operate/standby key Display screen

NICO® sensor input connection SpO2 sensor input connection CAPNOSTAT® CO2 sensor input connection

Serial number label

Power cord entry module (power cord receptacle and fuse housing) Rear panel power switch Power cord retainer (secure power cord) Equipotential connection (connection to monitor chassis)

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Rear panel power connectors

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2 Introduction 2.3

NICO® Monitor Technical Description

NICO® Monitor Technical Description Per requirements of IEC 601-1, the NICO® monitor is classified as class II equipment, internally powered, with type BF applied part, and an enclosure protection rating of IPX0. The NICO® monitor is Year 2000 compliant. Transport/Storage: -10 to +55° C (14-131° F), 10-95% R.H. non-condensing Operating Conditions: 10 to +40° C (50 to 104° F), 10-90% R.H. non-condensing

2.4

Manufacturing Quality & Safety The Respironics Novametrix, Inc. manufacturing facility is certified to both ISO 9001 and EN46001 (MDD93/42/EEC Annex II). Novametrix’ products bear the “CE 0086” mark. The product is certified by Underwriter’s Laboratories (UL) to bear the UL mark; and tested by TÜV Rheinland to IEC 601-1/EN60601-1. Respironics Novametrix, Inc. 5 Technology Drive Wallingford, CT 06489 U.S.A.

2.5

Declaration of Conformity with European Union Directive The Authorized Representative for Novametrix equipment is: D.R.M. Green European Compliance Services Limited, Oakdene House, Oak Road, Watchfield Swindon, Wilts SN6 8TD United Kingdom

2.6

Trademarks and Patents CAPNOSTAT, NICO, NICO2 are registered trademarks (®); CObar (cardiac output confidence bar), SuperBright and Y-Sensor are trademarks (™) of Respironics Novametrix, Inc. Other trademarks and registered trademarks are the property of their respective owners. The NICO® monitor and its sensors and accessories are covered by the following USA patents: 4,859,858, 4,859,859, 4,914,720, 5,146,092, 5,153,436, 5,190,038, 5,206,511, 5,251,121, 5,347,843, 5,369,277, 5,379,650, 5,398,680, 5,448,991, 5,535,633, 5,616,923, 5,693,944, 5,789,660, 5,793,044, 5,820,550, 5,891,026, 5,999,834, 6,042,550, 6,059,732, 6,098,622, 6,099,481, 6,126,610, 6,179,784, 6,200,271, 6,210,342, 6,227,196, 6,238,351, 6,241,681, 6,258,038, 6,306,098, 6,312,389, D424,193. Other patents pending.

2.7

Manual Revision History 27-Aug-99 2-Jul-02 19-Nov-02 9-Jul-03

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Release Revision 01, R-N1013 Revision 02, CO-N0020 Revision 03, CO_N0390

Rev. 03

3 3.1

Theory of Operation NICO® Model 7300 Non-Invasive Cardiac Output Monitor The NICO ® model 7300 monitor measures cardiac output based on changes in respiratory CO 2 concentration caused by a brief period of rebreathing. The measurement of cardiac output is accomplished by interpreting data collected by proprietary sensors that measure flow, airway pressure, and CO2 concentration, and then combining these signals to calculate CO2 elimination. Using these variables, a technique known as Fick partial rebreathing is applied to calculate cardiac output. NICO® can be used with mechanically ventilated patients in the operating room, intensive care, or emergency departments.

3.2 3.2.1

Digital Board 2763 Microprocessor Refer to sheet 1 of the 2763-03 schematic. The generation of the logic and control signals for the purpose of acquiring the raw physiological parameters, and management of the data needed to produce an accurate Non-Invasive Cardiac Output, are the responsibilities of microprocessor IC1. This device, a Motorola MC68332, is a highly integrated 32-bit microcontroller that combines high-performance data manipulation capabilities with powerful peripheral subsystems. These subsystems include circuitry for timing generation, peripheral chip selection and data control, interrupt generation, as well as synchronous and asynchronous serial communication. Also included is a sophisticated timing coprocessor, the TPU (Time Processor Unit), that can generate complex timing waveforms independent of the main processor. In general, the signals for subsystems are functionally grouped into ports which can be independently programmed by software to be a pre-defined port function or discrete I/O. Additionally, the functionality for several ports (Ports C, E and F) can be pre-defined by the state of specific data bus lines on system power-up. Included is a special “background mode” port that allows the device to be externally controlled, facilitating system debugging and testing. Also integrated on-chip are several activity monitors as well as a software watchdog to ensure proper device and system operation. Refer to table 1. Port

Defined Function

Functionality & Power-up Control

TPU 16 Channels

Timing Signal Generation

Each channel independently user programmable as TPU function or as Discrete I/O

Table 1: CPU Port Functions

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3 Theory of Operation

Digital Board 2763

QSM 4 Synchronous Serial Chip Selects & one asynchronous serial channel

Serial Communications Port: QSPI: Queued Serial Peripheral Interface SCI: Serial Communications Interface

QSPI chip selects independently user programmable, can be used as Discrete I/O or decoded to create up to 16 chip selects. SCI transmit can be programmed as Discrete I/O

Background Mode

System debugging

Allows an appropriate external device to control the microprocessor and system

C

Chip Selects

D0: CSBOOT* Data Width, 8 or 16bit D1: CS1*-CS3* or BR*,BG*,BGACK* D2: CS3*-CS5* or FC0-FC2 D3-D7: CS6*-CS10* or A19-A23

E

Bus Control

D8: Control Signals or Discrete I/O

F

MODCK and Interrupts

D9: MODCK & IRQ or Discrete I/O

Table 1: CPU Port Functions

The operating frequency of the system clock in the NICO® system is 24.117 MHz. It is generated by an internal VCO (Voltage Controlled Oscillator) derived from Y1, a 32.768KHz watch crystal, and is software programmable. The Timing Processor Unit (TPU) co-processor of the MC68332 provides complex timing functions generated from the system clock. This feature is utilized to control the precise timing required for the acquisition of the End Tidal Carbon Dioxide (etCO2) and saturation (SpO2) signals. The TPU is also used to generate the PWM (Pulse Width Modulation) control for the Capnostat Case and Detector heaters, and to provide the frequency generation for the audio tones. See Tables 2 and 3. Signal

Name

Function / Timing

CO2AZ

Auto Zero

Clears the Sample/Hold circuitry prior to data acquisition. Active High, 90 us

CO2PWENB

Pulse Width Enable

Defines the active time for both phases of the bipolar source pulse, used for pulse width protection circuitry. Active High, 810 us

SRCDRV0

Source Drive 0

First source drive signal. Active High, 405 us

CO2CSHL

Current Sample/Hold

Enables circuitry for source current measurement. Sample is taken when SRCDRV0 is active. Low = Sample, 90 us, High = Hold

SRCDRV1

Source Drive 1

Second source drive signal delayed for 10 microseconds after SRCDRV0 ends. Active High, 395 us

CO2SSH

Signal Sample/Hold

Enables circuitry for CO2 and Reference channel data acquisition. Low = Sample, 90 us, High = Hold

CASEPWM

Case Heater PWM

PWM control for the case heater servo

DETPWM

Detector Heater PWM

PWM control for the detector heater servo

Table 2: TPU Timing Generation for the etCO2 subsystem

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Digital Board 2763

TOUT1, TOUT2

Tone Generation

Variable frequency outputs to generate system audio

Table 2: TPU Timing Generation for the etCO2 subsystem

Signal

Name

Function / Timing

ASAMPL

Auto Zero

Clears the Sample/Hold circuitry prior to data acquisition. Active Low

RDLEDL

Red Channel LED control pulse

Defines the active time for the Red LED. Active Low

IRLEDL

Infra-Red Channel LED control pulse

Defines the active time for the Infra-Red LED. Active Low

RSAMPL

Red Channel Sample/Hold

Enables circuitry for the Red Channel signal measurement. Sample is taken when SRCDRV0 is active. Low = Sample, 90 us, High = Hold

ISAMPL

Infra-Red Channel Sample/Hold

Enables circuitry for the InfraRed Channel signal measurement. Sample is taken when SRCDRV0 is active. Low = Sample, 90 us, High = Hold

Table 3: TPU Timing Generation for the SpO2 subsystem

To help reduce and suppress the radiation of electromagnetic interference, ferrite filters (L1-L11) have been placed on clock signals with fast rise and fall times. Other digital signals, including address and data lines, are rise-time limited by the addition of small valued resistors and / or capacitors. In addition, good EMI/EMC design techniques have been incorporated in the component layout and printed circuit board manufacture. Table 4 lists the chip select, control and discrete I/O functions for the NICO® system module. On power-up, Ports E and F are programmed as discrete inputs by pulling down their controlling data lines, DB8 and DB9. After power-up, the software sets up each pin function individually and performs a series of self-tests to check the integrity of the system. During this period, the MPU holds the SYSUP line low which keeps the system in the initialization state. The state of configuration inputs on Port E (CNFG0, CNFG1 and CNFG2) and on data input buffer IC10 (see sheet 2 on 2763-03 schematic) (JP1, JP2, JP2, JP4, TP4, TP5 and TP6) are read. These inputs allow the software to identify different operating conditions, such as Manufacturing Diagnostic Mode, or to recognize different hardware configurations. After the initialization period is complete and all system functions have been set, the MPU brings the status signal SYSUP high, indicating that the system is ready for patient monitoring operation.

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3 Theory of Operation

Digital Board 2763

Port

Pin Functions

System Signal

I/O

Comments

O

D0-D7 pulled high, Pins are Chip Select on power-up

Name1 C

E

DATA0 thru DATA7 CSBOOT*

ROMOEL

O

Program PROM Chip Select Word (16-bits) wide mode, D0 = HIGH

CS0* / BR*

UBRAMWRL

O

Upper Byte SRAM Write Enable Allows for byte (8-bit) or word writes

CS1*/ BG*

LBRAMWRL

O

Lower Byte SRAM Write Enable Allows for byte (8-bit) or word writes

CS2* / BGACK*

SRAMOEL

O

SRAM Read Enable, Word

CS3* / PC0 / FC0

ROMWRL

O

FLASH PROM Write Enable, Word

CS4* / PC1 / FC1

UARTCSL

O

High Speed quad UART Chip Select

CS5* / PC2 / FC2

BOOTWE

O

Port C Discrete Output, prevents unintentional writes to FLASH EPROM. This signal must be asserted before ROMWR* in order to overwrite the FLASH

CS6* / PC3 / A19

A19

O

High Address line A19

CS7* / PC4 / A20

RTCCSL

O

Real Time Clock Chip Select

CS8* / PC5 / A21

DISPCSL

O

EL Display Chip Select

CS9* / PC6 / A22

VRAMCSL

O

Video Memory Chip Select

CS10* / ECLK / A23

CASCADEL

O

Cascaded Chip Select for Additional Parallel Peripherals

O

D8 pulled low, Discrete I/O on power-up

DATA8 DSACK0* / PE0

CNFG2

I

Configuration Switch 2

DSACK1* / PE1

DS1L

I

Data and Size Acknowledge 1*

AVC*

/ PE2

CNFG0

I

Configuration Switch 0

RMC*

/ PE3

CNFG1

I

Configuration Switch 1

DS*

/ PE4

DSL

O

Data Strobe

AS*

/ PE5

ASL

O

Address Strobe

SIZ0*

/ PE6

SIZ0

O

Signifies current operation is 8-bit data

SIZ1*

/ PE7

CNFG2

I

Configuration Switch 2

RDL

O

Data Read Strode

WRL

O

Data Write Strobe

R/W*

Table 4: Chip Select, Control and Discrete I/O

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Digital Board 2763

F

DATA9

O

D9 pulled low, Discrete I/O on power-up

MODCLK / PF0

LED

O

LED CPU Activity Indicator

IRQ1*

/ PF1

SYSUP

O

System Initialization Complete

IRQ2*

/ PF2

CSOFTOT

O

Case Heater Over Temperature Shut Down

IRQ3*

/ PF3

DSOFTOT

O

Detector Heater Over Temperature Shut Down

IRQ4*

/ PF4

UARTIRQL

I

External UART Interrupt

IRQ5*

/ PF5

EXTDCIN

I

Indicates external AC MAINS power operation

IRQ6*

/ PF6

PWRDWN

O

System power down enable

IRQ7*

/ PF7

NMIL

I

Non-Maskable Interrupt

Table 4: Chip Select, Control and Discrete I/O 1.Signal names with an “L” suffix are active low signals.

3.2.2

Background Mode Debugging and Application Development Refer to sheet 1 on 2763-03 schematic. Background debugging of the system during applications development or during system testing is possible by connecting an appropriate external device (emulator or debugger) to header J1. The signals present on this header enable an external device to halt the current microprocessor bus activity. This turns control of the microprocessor system over to the external device, placing the microcontroller into Background Debugging Mode. In this mode, the internal MPU registers can be viewed and altered, special test features can be invoked and the system’s memory, and peripherals can be read and written to. To enable this, header J1 and 0 ohm resistors R106 and R107 need to be populated. Refer to sheet 2 on 2763-03 schematic. In addition to the inherent debugging capabilities of the microprocessor, the digital board also contains circuitry to monitor events during application development. Output latches IC15 and IC17 along with Profiling header J4 are used to determine CPU utilization during system development, latching various status bits out on the header.

3.2.3

System Memory Refer to sheet 1 on 2763-03 schematic. A 16-bit wide data path is used for FLASH PROM and SRAM transfers to maximize system throughput. Non-volatile memory, used for the storage of the boot-up and main program code, is contained in IC4, a 1024K x 8-bit, 5V FLASH ROM. To initiate the data transfer process, the MPU brings the ROMOEL output signal LOW, causing a word of program data stored in the FLASH ROM to be sent out on the data bus from the appropriate memory address. Program data may be updated by commanding the device to erase a block of its present programmed data then using the ROMWRL signal to place new program data into the address specified by the MPU. The FLASH ROM is internally protected from unintentional overwrites of the boot code by requiring an independent signal, BOOTWE, going active in addition to ROMWRL. The BOOTWE line must be high prior to writing new boot code into the FLASH device. Two Static RAMs (IC3 and IC6) contain volatile data storage for use as a temporary data scratch pad during system operation and for recording patient trend information. To retain

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3 Theory of Operation

Digital Board 2763

patient trending data during periods of power down, the SRAMs are battery backed to retain their contents. A 2.5 Volt level VBACK generated from the main battery via IC30 on the 2764 Power Board, is supplied when the system is turned off and removed from the AC MAINS. During this battery backed-up state, transistor Q1 keeps the chip enable control line of the SRAMs high and in a low power, inactive state. This forces the SRAMs data bus to a high impedance state, isolating the parts from the rest of the system. True non-volatile storage for system parameters is provided by a serial EEPROM (IC8), which has the ability to retain programmed information in the absence of power.

3.2.4

User Interface Control Circuitry Refer to sheet 3 on 2763-03 schematic. The user interface features a high contrast, 320 row by 240 column Electroluminescent Display module. Patient and system information is presented in both graphical and textual formats organized into several screen configurations. An integrated display controller, IC19, works in conjunction with the MC68332 MPU, and provides the necessary timing signal generation and housekeeping functions to display the visual information generated by the system. Programmable logic device IC2 is designed to condition the logic signals between the MPU and display controller, making sure that the critical timing specifications of the two devices are met. SRAMS IC18 and IC22 provide video RAM storage for the display system. In addition to buffering the signals for the display interface, CPLD IC2 also decodes chip selects for the system input buffers and output latches off of CASCADEL. If required, IC2 can be reprogrammed in-circuit using header J9. A 5-switch silicon keypanel and multifunctional rotary encoder provide operator control of screen selection, patient data entry, and user selectable input. The keypanel also contains several LEDs which represent various system conditions such as input power status (AC or Battery) and alarm state. Control of the user interface is generated from the CASCADEL chip select signal along with the appropriate address line state and WRL signals from the microprocessor. IC10 and IC13 (sheet 2 on schematic) are input buffers, which read in the present state of the keypanel and rotary encoder. Depressing a key or activation of the encoder causes the signal line associated to be pulled low, in contrast to its normally high state. Input buffer IC14 provides a latched output for controlling the front panel LEDs as well as several other latched control outputs. To supplement the visual indicators associated with the membrane keypanel and display, an audio output signal is generated to provide an additional mode to convey information to the user. The TPU processor of the MC68332 (TOUT1 and TOUT2) can generate two-tone frequencies. These signals are fed into separate reference inputs of the Quad 8-bit DAC, IC20, providing a means for independently attenuating each signal under CPU control. From the DAC, the individual signals are summed together by IC21B and filtered by L11 and C50. Audio amplifier IC23 drives the system speaker to produce system audio. Inverter IC7F, controlled by the SYSUP signal from the MPU, disables the audio amplifier until system initialization has been completed. DAC IC23 also supplies an output voltage level SPO2VLED to set the current gain of the saturation drive circuit which is found on the NICO® Power PCB, 2764-01. The circuitry associated with the DACB output (including IC21A, Q3 and J6) is presently not used.

3.2.5

Real Time Clock, Power on RESET Generation and Glue Logic Refer to sheet 2 on 2763-03 schematic. Time keeping for date and time stamping of patient trend information is provided by Real Time Clock IC16. This device contains a built in crystal for precise time and date

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Model 7300 Service Manual

Rev. 03

Power Supply 2764 (Power Supply and Communications)

Theory of Operation 3

measurement. The NICO® system has been designed and tested for Y2K compliance. In the absence of AC power, the time keeping function is maintained by the battery backed-up supply, VBACK. On power-up, the system is forced into a RESET state by IC9 (sheet 1 on schematic). This chip creates the master active low system reset signal SRST*, holding up system initialization until a stable 5 VDC logic level is maintained. An inverter is used to generate RESET for devices that require an active high reset signal.

3.3 3.3.1

Power Supply 2764 (Power Supply and Communications) Serial Communications UART Refer to sheet 3 on 2764-03 schematic. To enable serial communication with up to three external devices simultaneously, a Quad UART (Universal Asynchronous Receiver/Transmitter), IC14, is provided for buffered high-speed data communication. The connection to external, non-patient contact-type devices is electrically isolated from the patient applied sections by optical data couplers (IC16, IC17, IC21, IC23, IC26) and isolated winding off of the power supply flyback transformer, T1. Transceiver IC13, located on the patient-isolated circuit, provides signal translation between the system’s TTL logic level and the RS-232 level requirements. Serial Ports A and C (J1 and J3) are configured for a simple 3-wire (Transmit, Receive and Ground) connection, while Serial Port B (J2) has additional hardware handshaking capabilities. Connection to an external device is through a nullmodem type of interface cable. The fourth UART channel is available on internal connector J5 for future product expansion. In addition, the system is capable of outputting four channels of analog output data through IC22 and receiving four channels of analog input through buffer amplifiers IC18 and A/D Converter IC20 on connector J4. Voltage reference IC19 supplies the analog I/O circuitry with a stable voltage level. Connector J4 allows sensing of external cable connection by shorting pin 15 (IOSNSE) of the external cable to ground. Refer to Tables 5 to 8 for the pinout and signals of interface connectors. J1 Pin Number

Signal

Function

1

NC

No Connection

2

RxC

Serial Channel A Receive

3

TxC

Serial Channel A Transmit

4

NC

No Connection

5

Isolated Ground

Non-Patient Signal Ground

6

NC

No Connection

7

NC

No Connection

8

NC

No Connection

9

NC

No Connection

Table 5: Serial Channel A, 9-pin D-subminiature connector located on the rear panel

Rev. 03

Model 7300 Service Manual

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