Huntleigh DA100PB User manual

771402-2 dopplex ABIlity Service Manual 1
SERVICE MANUAL

771402-2 dopplex ABIlity Service Manual 2
1 Table of Contents
1Table of Contents.................................................................................................................................. 2
2General................................................................................................................................................. 5
2.1 Standards compliance ................................................................................................................... 5
2.2 CE Mark........................................................................................................................................ 5
2.3 Classification................................................................................................................................. 5
2.4 Symbols ........................................................................................................................................ 6
2.5 Warnings....................................................................................................................................... 6
2.6 Cautions........................................................................................................................................ 6
2.7 System Connection........................................................................................................................ 6
2.8 Electromagnetic Compatibility........................................................................................................ 7
2.9 Electrostatic Discharge.................................................................................................................. 9
2.10 Service & Warranty........................................................................................................................ 9
2.11 Addresses ....................................................................................................................................10
3Introduction..........................................................................................................................................11
4Initial Unit Set-Up.................................................................................................................................12
4.1 Battery Connection.......................................................................................................................12
5Product Description..............................................................................................................................13
5.1 Front panel connections and controls............................................................................................13
5.2 Rear Panel ...................................................................................................................................13
5.3 Base.............................................................................................................................................14
5.4 Product Labelling..........................................................................................................................14
5.5 User Interface...............................................................................................................................16
5.6 System Connection.......................................................................................................................18
6System Block Diagram.........................................................................................................................19
6.1 Base PCB assembly:....................................................................................................................20
6.2 Daughter PCB assembly:..............................................................................................................21
6.3 Regulator PCB assembly:.............................................................................................................21
6.4 Front panel PCB assembly: ..........................................................................................................21
6.5 Printer Interface PCB:...................................................................................................................21
6.6 Manifold assembly........................................................................................................................21
6.7 Pneumatic Circuit Diagram ...........................................................................................................22
7Operating Principles.............................................................................................................................25
7.1 Cuff Inflation & Deflation Control...................................................................................................26
7.2 Brachial occlusion cuff chambers..................................................................................................26
7.3 Ankle occlusion cuff chambers......................................................................................................26
7.4 All detect chambers......................................................................................................................26
7.5 Systolic Pressure Determination ...................................................................................................26
7.6 System Faults...............................................................................................................................26
8Product Specifications..........................................................................................................................28
8.1 Equipment Classification...............................................................................................................28
8.2 Performance.................................................................................................................................28
8.3 Environmental...............................................................................................................................28
8.4 General ........................................................................................................................................29

771402-2 dopplex ABIlity Service Manual 3
9Disassembly & Assembly.....................................................................................................................30
9.1 Tools Required.............................................................................................................................30
9.2 Case Front (SP-771054) Removal................................................................................................31
9.3 Case Rear Removal .....................................................................................................................32
9.4 Base PCB (SP-7711067) Removal ...............................................................................................34
9.5 KEYPAD (SP-771335) REPLACEMENT.......................................................................................35
9.6 CONNECTOR REMOVAL/REPLACEMENT .................................................................................36
9.7 IEC MAINS INLET (SP-771499) REPLACEMENT.........................................................................37
9.8 Printer Door/Roller (SP-771535) Replacement..............................................................................38
9.9 Printer Mechanism (SP-771537) Replacement..............................................................................39
9.10 Fuse (SP-771539) replacement....................................................................................................41
9.11 PSU Module (SP-771517) Replacement.......................................................................................42
9.12 Regulator PCB (SP-771551) Replacement ...................................................................................43
9.13 Pump (SP-771552) Replacement..................................................................................................44
9.14 Valve (SP-771505) Replacement..................................................................................................45
9.15 Solenoid Valve (SP-771585) Replacement ...................................................................................45
9.16 Over Pressure PCB (SP-771507) Replacement............................................................................46
9.17 Base PCB (SP-771067) Replacement...........................................................................................47
9.18 Manifold (SP-771053) Replacement..............................................................................................48
9.19 REAL TIME CLOCK BATTERY (SP-771514) Replacement ..........................................................50
10 Safety Testing......................................................................................................................................51
10.1 Product Classification ...................................................................................................................51
10.2 Electrical Safety Test: Mains Inlet to Enclosure Leakage Current ..................................................51
10.3 Electrical Safety Test: USB (Enclosure Leakage) Test ................................................................52
10.4 Electrical Safety Test: Printer (Enclosure Leakage) Test .............................................................53
11 Maintenance ........................................................................................................................................54
11.1 Automatic Service Prompt & Service Report .................................................................................54
11.2 Air Filter Replacement ..................................................................................................................54
11.3 Rechargeable Battery Conditioning or Replacement .....................................................................54
11.4 Cuffs.............................................................................................................................................55
11.5 General Inspection........................................................................................................................56
11.6 Real Time Clock Battery Check ....................................................................................................56
12 Performance Verification......................................................................................................................57
12.1 Flow Test......................................................................................................................................57
12.2 Leak Test .....................................................................................................................................58
12.3 ADC Check and Overpressure Reset Check.................................................................................58
12.4 Pressure Calibration.....................................................................................................................59
12.1 Printer Test...................................................................................................................................59
12.2 Hardware Monitor Test .................................................................................................................60
13 Software Upgrade ................................................................................................................................60
13.1 Upgrade Utility User Instructions – Internet Method.......................................................................60
13.2 Upgrade Utility User Instructions – Non-Internet Method...............................................................62
14 Fault Modes.........................................................................................................................................63
14.1 Introduction...................................................................................................................................63
14.2 Descriptive Faults.........................................................................................................................63
14.3 Internal Faults...............................................................................................................................69
15 Spare Parts..........................................................................................................................................72
15.1 Ordering Spare Parts....................................................................................................................72
15.2 Spare Parts ..................................................................................................................................72
Issue History
Issue
Date
CN
Notes
1
- - - -
Draft issue. Applicable to software V2.224.
2
28/2/13
10220
Semi-automated service test functions included. Valid from
software version 2.235.

771402-2 dopplex ABIlity Service Manual 4
Periodic inspection and preventative maintenance are essential to ensure continued effective
operation. Contact the Company or its approved agents or distributors for further information on
service contracts.
Manufactured in the UK by Huntleigh Healthcare Ltd.
As part of the ongoing development programme the company reserves the right to modify
specifications and materials without notice.
Dopplex, Ability and Huntleigh are registered trademarks of Huntleigh Technology Ltd. 2011.
© Huntleigh Healthcare Ltd. 2011

General
771402-2 dopplex ABIlity Service Manual 5
2 General
2.1 Standards compliance
The dopplex Ability complies with:
EN60601-1: 1990 + A1, A2, A11,
A12 & A13
Medical Electrical Equipment Part 1
General Requirements for Safety
EN60601-1-1: 2001
[collateral standard] Safety Requirements for Medical Electrical Systems
EN60601-1-2: 2001
[collateral standard] General requirements for safety: Electromagnetic compatibility
EN10993-1: 2009 & AC: 2010
Biological Evaluation of Medical Devices; Guidance on selection of tests
EN62366 :2008
General requirements for basic safety and essential performance -
Collateral standard: Usability
IEC 62304: 2006
Medical device software - Software life cycle processes.
BS EN 980:2008
Symbols for use in the labelling of medical devices
2.2 CE Mark
The dopplex Ability is in conformity with the Medical Devices Directive
93/42/EEC as amended by 2007/47/EC and has been subject to the
conformity assurance procedures laid down by the Council
2.3 Classification
Type of protection against
electric shock.
Class II and Internally powered equipment with a functional earth
terminal, which provides a ground path for the internal mains filter.
Degree of protection against
electric shock Type BF - equipment with an applied part.
Mode of operation.
Continuous
Degree of protection against
harmful ingress of particles
and/or water.
IP30
Degree of safety of application
in the presence of a flammable
anaesthetic
Equipment not suitable for use in the presence of a FLAMMABLE
ANAESTHETIC MIXTURE WITH AIR, OXYGEN OR NITROUS OXIDE

General
771402-2 dopplex ABIlity Service Manual 6
2.4 Symbols
WARNING: .....
Indicates the possibility of death or serious injury
CAUTION: ......
Indicates the possibility of personal injury or material damage.
Attention, consult accompanying documents / Instructions for Use
2.5 Warnings
WARNING: A possible explosion hazard exists if used in the presence of flammable
anaesthetics.
WARNING: Do not operate the unit from the mains supply if the mains cable is damaged.
WARNING: Do not immerse any portion of the unit in water or other liquids.
WARNING: If this product is connected to another item of electrical equipment, it is
important that the system is fully compliant with EN60601-1-1.
WARNING: When configuring the system, consider and minimise the risk of persons tripping
over the tubing and electrical cables
2.6 Cautions
Observe ESD (electrostatic discharge) precautions
when working within the unit and/or when
disassembling and reassembling the dopplex Ability
and when handling any of the
components of the dopplex Ability.
2.7 System Connection
WARNING: These requirements must be met when a dopplex Ability is connected to any
other electrical equipment, such as a PC.
Non-medical equipment must comply with the relevant IEC or ISO safety standard. For Information
Technology equipment, this standard is IEC950/ EN60950.
Medical equipment must comply with IEC601-1/EN60601-1, or equivalent.
The configured system must comply with the requirements of IEC60601-1:2005; clause 16.
If non-medical equipment (e.g. the PC or printer) with enclosure leakage currents greater than those
allowed by IEC601-1/ EN60601-1 is to be used in the patient environment (within 1.5m of the patient),
the enclosure leakage currents must be brought within the limits laid down by IEC601-1/EN60601-1.
This may be achieved by using a medical grade isolating transformer. Suitable types are available via
Huntleigh sales agents.
Anyone who connects additional equipment to signal input or signal output parts of the system is
configuring a medical system, and is therefore responsible for ensuring that the system complies with
the requirements of IEC60601-1:2005; clause 16. If there is any doubt as to whether your system
complies, consult the technical service department of your local Huntleigh representative.

General
771402-2 dopplex ABIlity Service Manual 7
2.8 Electromagnetic Compatibility
Make sure the environment in which dopplex Ability is installed is not subject to strong sources of
electromagnetic interference (e.g. radio transmitters, mobile phones).
This equipment generates and uses radio frequency energy. If not installed and used properly, in strict
accordance with the manufacturer’s instructions, it may cause or be subject to interference. Type-tested
in a fully configured system, complies with EN60601-1-2, the standard intended to provide reasonable
protection against such interference. Whether the equipment causes interference may be determined by
turning the equipment off and on. If it does cause or is affected by interference, one or more of the
following measures may correct the interference:
Reorienting the equipment
Relocating the equipment with respect to the source of interference
Moving the equipment away from the device with which it is interfering
Plugging the equipment into a different outlet so that the devices are on different branch circuits
WARNING: The use of accessories, transducers and cables other than those specified, with the
exception of transducers and cables sold by the manufacturer of the dopplex Ability as replacement
parts for internal components, may result in increased emissions or decreased immunity of the
dopplex Ability.
WARNING: The dopplex Ability should not be used adjacent to or stacked with other equipment and
that if adjacent or stacked use is necessary, the dopplex Ability should be observed to verify normal
operation in the configuration in which it will be used.
Guidance and Manufacturer’s declaration - electromagnetic emissions
The dopplex Ability is intended for use in the electromagnetic environment specified below. The customer or the user of the dopplex Ability
should assure that it is used in such an environment.
Emissions Test
Compliance
Electromagnetic Environment - guidance
RF emissions
CISPR 11 Group 1
The dopplex Ability uses RF energy only for its internal function. Therefore, its RF emissions are
very low and are not likely to cause any interference in nearby electronic equipment.
RF emissions
CISPR 11
Class B
The dopplex Ability is suitable for use in all establishments, including domestic establishments
and those directlyconnected to the public low-voltage power supply network that supplies
buildings used for domestic purposes.
Voltage fluctuations /
flicker emissions
IEC 61000-3-2
Class A
Harmonic emissions
IEC 61000-3-3
Complies

General
771402-2 dopplex ABIlity Service Manual 8
Guidance and Manufacturer’s declaration - electromagnetic immunity
The dopplex Ability is intended for use in the electromagnetic environment specified below. The customer or the user of the
dopplex Ability should assure that it is used in such an environment.
Immunity Test
IEC 60601 test
level
Compliance
level
Electromagnetic Environment -
guidance
Portable and mobile RF communications
equipment should be used no closer to
any part of the dopplex Ability, including
cables, than the recommended
separation distance calculated from the
equation applicable to the frequency of
the transmitter.
Conducted RF
IEC 61000-4-6
3 Vrms
150kHz to 80MHz
3V d = 1.2 √P
Radiated RF
IEC 61000-4-3
3 Vrms
80MHz to 2.5MHz
3V/m
d = 1.2 √P 80MHz to 800MHz
d = 2.3 √P 800MHz to 2.5GHz
where P is the maximum output power
rating of the transmitter in watts (W)
according to the transmitter manufacturer
and d is the recommended separation
distance in metres (m).
Field strengths from fixed RF
transmitters,
as determined by an electromagnetic
site survey, a should be less than the
compliance level in each frequency
range b.
Interference may occur in the vicinity of
the equipment marked with the following
symbol:
NOTE 1 At 80MHz and 800MHz, the higher frequency range applies.
NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and
rejection from structures, objects and people.
a Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land mobile
radios, amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To
assess the electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey should be considered.
If the measured field strength in the location in which the dopplex Ability is used exceeds the applicable RF compliance level
above, the dopplex Ability should be observed to verify normal operation. If abnormal performance is observed, additional
measures may be necessary, such as re-orienting or relocating the dopplex Ability.
b Over the frequency range 150kHz to 80kHz, field strengths should be less than 3V/m.

General
771402-2 dopplex ABIlity Service Manual 9
Recommended separation distances between portable and mobile RF communications
equipment and the dopplex Ability
The dopplex Ability is intended for use in an electromagnetic environment in which radiated RF disturbances are controlled.
the customer or user of the dopplex Ability can help prevent electromagnetic interference by maintaining a minimum
distance between portable and mobile RF communications equipment (transmitters) and the dopplex Ability as
recommended below, according to the maximum output power of the communications equipment.
Rated maximum
output power of
transmitter
W
Separation distance according to frequency of transmitter
m
150kHz to 80MHz
d = 1.2 √P
80MHz to 800MHz
d = 1.2 √P
800MHz to 2.5GHz
d = 2.3 √P
0.01
0.12
0.12
0.23
0.1
0.38
0.38
0.73
1
1.2
1.2
2.3
10
3.8
3.8
7.3
100
12
12
23
For transmitters rated at a maximum output power not listed above, the recommended separation distance d in metres (m)
can be estimated using the equation applicable to the frequency of the transmitter, where P is the maximum output power
rating of the transmitter in watts (W) according to the transmitter manufacturer.
NOTE 1 At 80MHz and 800MHz, the separation distance for the higher frequency range applies.
NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and
reflection from structures, objects and people.
2.9 Electrostatic Discharge
Electrostatic discharge (ESD) is a known problem that can affect electrical equipment. If the dopplex Ability is
subjected to ESD during an ABI measurement, it is possible that the measurement will be suspended. The air in
all cuff chambers will be rapidly exhausted, and the unit will reset to the start-up screen.
If this happens, simply perform the usual checks and repeat the test.
2.10 Service & Warranty
Huntleigh Healthcare's standard terms and conditions apply to all sales. These contain full details of warranty
terms and do not limit the statutory rights of the consumer. A copy is available on request.
If there is any reason to return the dopplex Ability unit, please:
1. Clean the product, as described in the cleaning section.
2. Pack it in suitable packing.
3. Attach the decontamination certificate (or other written statement declaring that the product has
been cleaned) to the outside of the package.
4. Mark the package "Service Department – dopplex Ability” and return to the address below.
Huntleigh Healthcare Ltd reserve the right to return product that does not contain a decontamination
certificate.

General
771402-2 dopplex ABIlity Service Manual 10
2.11 Addresses
UK:
Huntleigh Healthcare Ltd. – Diagnostic Products Division
35 Portmanmoor Road, Cardiff,
CF24 5HN United Kingdom
T: [phone]
F: [phone]
E: [e-mail]
W: www.huntleigh-diagnostics.com
E-mail:
[e-mail]

Introduction
771402-2 dopplex ABIlity Service Manual 11
3 Introduction
This manual contains information for servicing the dopplex Ability. Only qualified service personnel should
service this product. Before servicing the dopplex Ability, read the products Instructions for Use Manual carefully
for a thorough understanding of safe operation.
Read and understand all safety warnings and service notes printed in this service manual and the user’s
manual.
The fault finding described is only intended to identify boards, modules or major components that need to be
replaced. This document is not intended as a full diagnostic tool because many of the boards and modules
cannot be satisfactorily repaired in the field and must be returned to Huntleigh Healthcare if faulty.
If any warranty claim is intended then it is important to ensure that any security seals are intact on the items to
be returned if the warranty is not to be invalidated.
To isolate the dopplex Ability from the mains or line supply, disconnect the power cable
from the mains inlet at the rear of the unit

Initial Unit Set-Up
771402-2 dopplex ABIlity Service Manual 12
4 Initial Unit Set-Up
On delivery of a new unit the battery will not be connected. Prior to performance testing the battery will need to
be connected and conditioned. The conditioning routine will automatically operate when the dopplex Ability is
switched on for the first time.
4.1 Battery Connection
Make sure the unit is NOT connected to the mains supply before proceeding.
4.1.1 Invert the unit and remove the battery cover by removing the securing screw using the Allen key
provided.
4.1.2 Lift the battery out, and connect the battery to the unit.
4.1.3 Replace the battery, re-fit the battery cover (ensure that the air filter is still in place) and replace the
securing screw with the Allen key provided. DO NOT OVERTIGHTEN!
The battery should now be conditioned by connecting the unit to the mains supply. The battery conditioning
mode will automatically start when the unit is first switched on. Battery conditioning will take 8-10 hours. When
complete the unit will switch off automatically.

Product Description
771402-2 dopplex ABIlity Service Manual 13
5 Product Description
It is intended to be used on all patients considered to be at risk of having, or developing peripheral arterial
disease (PAD).
Dopplex Ability is intended for the rapid measurement of ankle-brachial pressure index (ABPI) or ankle-brachial
index (ABI) in adults and pulse volume recording (PVR) / volume plethysmography.
Ability is suitable for use in woundcare assessment, for assessing symptomatic PAD, and as a screening device
for PAD.
It may also be used on patients with venous or arterial ulcers prior to the application of compression therapy.
Dopplex Ability can be used on patients with unilateral lower limb amputation.
5.1 Front panel connections and controls
1
On/Off Button
2
Display
3
Function Buttons
4
Colour Coded Tubes
5.2 Rear Panel
1
Mains Inlet
2
Printer Cover
3
COM Port connector (USB)

Product Description
771402-2 dopplex ABIlity Service Manual 14
5.3 Base
1
Battery Cover
2
Battery Cover Retaining Screw
3
Slide Plate Mounting Boss
4
Air Filter
5.4 Product Labelling

Product Description
771402-2 dopplex ABIlity Service Manual 15

Product Description
771402-2 dopplex ABIlity Service Manual 16
5.5 User Interface User Set-Up Options Menu
Service Menu Map
-Exit
-Contrast
-Set Time/Date
-Paper Type
-Audio Volume
-Classification
-Waveforms
-Language
-Battery Conditioner
-Service Menu
Refer to User Service Menu Map

Product Description
771402-2 dopplex ABIlity Service Manual 17
PIN Code
5315
-Exit
-Demo Mode
-Calibration
-ADC Check
(Also tests overpressure sensor)
-Cuff Leak Test - Tests cuffs for leakage
-Record Service -Enters Date of Service into memory
-Print Service Report -Prints report using internal printer
-Test Printer -Initiates a Test Printout
-Flow Test - Tests for pneumatic integrity
-Hardware Monitor - Checks function of independent timer

Product Description
771402-2 dopplex ABIlity Service Manual 18
Patient Type Set-Up Menu Map
5.6 System Connection
WARNING: These requirements must be met when a dopplex Ability is connected to any
other electrical equipment, such as a PC.
1. Non-medical equipment must comply with the relevant IEC or ISO safety standard. For Information
Technology equipment, this standard is IEC950/ EN60950.
2. Medical equipment must comply with IEC601-1/EN60601-1, or equivalent.
3. The configured system must comply with the Medical System standard IEC601-1-1/ EN60601-1-1.
4. If non-medical equipment (e.g. the PC or printer) with enclosure leakage currents greater than those
allowed by IEC601-1/EN60601-1 is to be used in the patient environment (within 1.5m of the patient),
the enclosure leakage currents must be brought within the limits laid down by IEC601-1/EN60601-1.
This may be achieved by using a medical grade isolating transformer. Suitable types are available via
Huntleigh sales agents.
5. Anyone who connects additional equipment to signal input or signal output parts of the system is
configuring a medical system, and is therefore responsible for ensuring that the system complies with
IEC60601-1-1/EN60601-1-1. If there is any doubt as to whether your system complies, consult the
Service Department of your local Huntleigh representative.

System Block Diagram
771402-2 dopplex ABIlity Service Manual 19
6 System Block Diagram
Front Panel PCB
Regulator PCB
Pneumatics
LCD Display
Printer
Power down
Keypad ON/OFF
DAC
(16 bit)
Gas-
gauge
Isolated Area
HUNTLEIGH HEALTHCARE 77130xx A 1 of 1
RHOOSE (HD771)
Pressure Sensors Solenoid Valves
Pump
SV SVSV SV SV
MCU
(ARM9)
SPI bus
PSRAM
Solenoid Valves
6.0V_SW
6.0V
LV LV LV
Linear Valves
6.0V _SW
Solenoid control
Pump control
(opt)
Reset
Reset
Base PCB
Solenoid Drivers Drivers
Overcurrent signal
6.0V_SW
5.0V Linear regulator
6.0V
Amp
ADC
PS PS PS PS PS PS PS SV SVSV SV
SPI I/F GP IO
Daughter PCB
All one chip
Solenoid Drivers
Sensor Interface
5.0V, 3.3V
LED Backlight Control
Buffer / Level Shifter
Printer I/F
Connectors for Cuffs
Power-path
controller
6.0V Switcher
Vcc
5.0V Switcher
1.8V Switcher
En En En En En
System power rails
MCU
(PIC)
Isolated Area
5.0V, 6.0V
Mains
Inlet
Isolated Area
3.3V Switcher
5V PERM Lin
Hardware monitor
EEPROM
I2C bus
Printer PCB
USB
Connecor USB
Isolator
Bus or Port
Control
Circuit block
Key:
Peripheral
Device
Pneumatics
Supply
Power
PCB
Isolation
Multiple
Power up sequencing
15V switcher
Indicator
Indicator
On-off control
Charging
LCD I/F
Linear Valves
Solenoids
Sensor Signals
Printer electronics
(Fujitsu)
Boost 20V
LS
Driver
Dig
Pot
Audio
Control
Battery Charger
14V PSU
Programmable
Device
EM Power Switch
Driver
P
P
P
P
Keypad
Pump
The unit is divided into six main assemblies:

System Block Diagram
771402-2 dopplex ABIlity Service Manual 20
•Base PCB assembly.
•Daughter PCB assembly.
•Regulator PCB assembly.
•Front panel PCB assembly.
•Printer PCB.
•Manifold assembly.
6.1 Base PCB assembly:
MCU: This is the main control / data processing block of the system. The MCU is
responsible handling user input, presenting data on LCD, handling of printer,
and processing of raw PVR signals.
USB Isolator: Provides full speed isolated USB 2.0 interface to PC hardware. The isolation is
rated at 5KVrms for 1 minute.
PSRAM: Provides temporary storage for the main ABI determination algorithm (64Mb).
EEPROM: Provides non-volatile storage of factory and user settings.
Hardware Monitor: Provides a software-independent safety function to ensure all cuffs are safely
deflated in case of software failure.
DAC: Generates analogue drive voltage required to operate the linear valves.
Digital POT: Used to control the audio volume.
BOOST: Used to step-up the main PSU voltage to the level required for optimal battery
charging.
Battery Charger: Provides all the functions required for reliable charging and charge termination
of the NiMH rechargeable battery.
Gas-gauge: The gas-gauge monitors the battery state of charge and employs a self-learning
algorithm to compensate for battery ageing and self-discharge rate. The gas-
gauge circuit is always powered from 5V_PERM rail.
Charge Indicator: The charge indicator is used to flash the front panel LED indicating that battery
charging is in progress.
Keypad: Provides three function keys for user interaction plus ON/OFF control.
Solenoid Drivers: Provide ON/OFF control of five of the solenoid valves.
Pump Driver: Provides ON/OFF and filtering of the PWM drive signals for the air pump.
Linear Valve Drivers: Provides the necessary drive voltage for reliable operation of the linear valves.