VersaPulse Select Service Manual

VersaPulse® Select™

SERVICE MANUAL

This service manual is to be used in conjunction with the operator manual for the product. The operator manual contains important information regarding instrument description, location of controls, specifications, and normal operating procedures.

DANGER

VISIBLE AND INVISIBLE LASER RADIATION. AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION.

HOLMIUM:YAG LASER: 2.1 MICROMETERS MAX OUTPUT 5 JOULES 250 µs PULSE Nd:YAG LASER: 1.06 MICROMETERS MAX. OUTPUT 2 JOULE 350 µs PULSE DIODE LASER: 650 NANOMETERS MAX OUTPUT 5 MILLIWATTS

CLASS IV LASER PRODUCT

Santa Clara, CA 95051

DANGER

2400 Condensa Street

(408) 764-3000

VISIBLE AND INVISIBLE LASER RADIATION. AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION.

HOLMIUM:YAG LASER: 2.1 MICROMETERS MAX OUTPUT 5 JOULES 250 µs PULSE DIODE LASER: 650 NANOM ETERS MAX OUTPUT 5 MILLIWATTS

CLASS IV LA SER PRODUCT

0621-499-01

DEC. 95

This manual is copyrighted with all rights reserved. Under the copyright laws, this manual cannot be copied in whole or part without the express written permission of Coherent, Inc. Permitted copies must carry the same proprietary and copyright notices as were affixed to the original.

Please note that while every effort has been made to ensure that the data given is accurate, the information, figures, illustrations, tables, specifications, and schematics are subject to change without notice.

Coherent and the Coherent Logo are registered trademarks of Coherent, Inc.

Please direct all inquiries about this manual to:

Coherent, Inc. Technical Support B-35 2400 Condensa Street Santa Clara, CA 95051 (408) 764-3638

DISCLAIMER

Coherent service manuals are written specifically for use by Coherent service engineers who have received formal training in the servicing of Coherent equipment, and by customers who have taken and passed a Coherent certification service training course for the equipment being serviced. Information on certification service training courses offered to customers can be obtained by contacting the Technical Training Coordinator at 800-367-7899.

Coherent does not accept responsibility for personal injury or property damage resulting from the servicing of Coherent equipment by its customers or by third parties, except where such injury or property damage is a direct result of Coherent's negligence. Customers, by accepting the service manual, agree to indemnify Coherent against any claims alleging personal injury or property damage resulting from the servicing of Coherent equipment by the customer or by third parties, except where such injury or property damage is a direct result of Coherent's negligence. These limitations include situations where Coherent personnel are advising customers on the repair of Coherent equipment over the telephone.

The servicing of Coherent equipment by persons who have not passed a current Coherent certification service training course for that equipment will void Coherent's product warranty.

VersaPulse Select Service Manual Disclaimer 0621-499-01 12/95

REVISION INFORMATION

This is the DEC '95 release of the Versapulse Select Service Manual. Contact Coherent Medical Group Technical Support to determine if this is the most current release of this service manual.

Each page of this manual has a MM/YY date at the bottom. This indicates the release date for the individual page. Note that when the manual is updated, not all of the pages are necessarily updated, so some pages may have a MM/YY earlier than the release date for the manual (the release date for the manual is the MM/ YY that appears on the cover and in the first sentence of this revision information page). The following list provides a complete list of the release date information, by section, for this release of the service manual.

Cover page, copyright page, disclaimer page, this page, table of contents page or pages are all dated with the release date of the manual (12/95).

SECTION 1 Pages 1-1, 01/94

Pages 1-2, 12/95

SECTION 2 Pages 2-1,4,6 12/95. All other pages 03/94.

SECTION 3 Pages 3-1 thru 3-10 12/95. All other pages, 03/94.

SECTION 4 Pages 4-4 Thru 4-17, 4-22 Thru 4-30, 12/95.

All other pages, 01/94

SECTION 5 All pages, 12/95

SECTION 6 All pages, 12/95

SECTION 7 FSB's released for this service manual are listed in the Versapulse Select FSB

Index. Each time an FSB for this manual is released or updated the Index is also updated and distributed with the FSB. The current Index is placed behind the single sheet that makes up Section 7, and the FSB's are placed in order behind the Index. Contact Coherent Medical Group Technical Support for the date of the most current FSB Index.

SECTION 8 Page 8-1,12, 10/95

Pages 8-2 thru 8-11, 8-13 thru 8-18, 01/94 Pages 8-19 thru 8-30, 08/95

VersaPulse Select Service Manual Revision Information 0621-499-01 12/95

Table Of Contents

DISCLAIMER .................................................................................................................................................. 3

REVISION INFORMATION ........................................................................................................................ 4

1.0 GENERAL INFORMATION ............................................................................................................... 1

1.1 USE OF THIS MANUAL .......................................................................................................................1

1.2 CONVENTIONS USED IN THIS MANUAL.......................................................................................1

1.3 SERIAL NUMBERS ............................................................................................................................... 2

2.0 INSTALLATION ....................................................................................................................................1

2.1 INSTALLATION INSTRUCTIONS......................................................................................................1

3.0 CALIBRATION & ADJUSTMENT ....................................................................................................1

3.1 OVERVIEW............................................................................................................................................ 1

3.1.1 Safety Precautions ..................................................................................................................................1

3.2 System Check Out .................................................................................................................................. 2

3.3 Energy Monitor and Automatic Laser Calibration..............................................................................5

3.4.1 Making Test Burns .................................................................................................................................. 7

3.4.2 Adjusting the YAG Channel Optics .......................................................................................................7

3.4.3 YAG Channel Check Out and Adjustment Procedure......................................................................... 8

3.5 AIMING BEAM ADJUSTMENT ........................................................................................................10

3.6 PERIODIC MAINTENANCE REQUIREMENTS............................................................................ 13

4.0 THEORY OF OPERATION.................................................................................................................. 1

4.1 INTRODUCTION ...................................................................................................................................1

4.1.1 Operational Overview ............................................................................................................................. 1

4.1.2 Functional Overview ...............................................................................................................................2

4.2 POWER SWITCHING, CONDITIONING, DISTRIBUTION .......................................................... 5

4.2.1 Input Power..............................................................................................................................................5

4.2.2 Circuit Breaker on, Keyswitch off .........................................................................................................5

4.2.3 Turn on ..................................................................................................................................................... 5

4.2.4 Shutdown..................................................................................................................................................6

4.2.5 Low Voltage Power Supplies................................................................................................................... 6

4.3 COOLING................................................................................................................................................7

4.4 CONTROL ELECTRONICS ................................................................................................................. 9

4.4.1 Overview...................................................................................................................................................9

4.4.2 Main Processor ...................................................................................................................................... 10

4.4.3 Shutter / Footswitch / Remote Interlock Circuits............................................................................... 11

4.4.4 Servo Motor Control Circuit ................................................................................................................ 13

4.4.5 HVPS & PFN Control Circuits ............................................................................................................14

4.4.6 Energy Monitor Circuits.......................................................................................................................17

4.4.7 Touch Screen & Remote Control Circuits ........................................................................................... 18

4.4.8 Aiming Diode Laser Circuit..................................................................................................................20

4.4.9 Fiber and Blast Shield Position Sense Circuits ...................................................................................21

4.4.10 Service Attenuator Circuit .................................................................................................................. 22

4.4.11 Coolant Temperature and Conductivity Monitoring Circuits.........................................................23

4.4.12 Low Energy Attenuator Circuit ......................................................................................................... 24

4.4.13 DC Power Supply Voltage Monitoring Circuits.................................................................................24

4.4.14 Safety Processor....................................................................................................................................25

4.5 FLASH LAMP POWER CIRCUITS.................................................................................................. 27

4.6 OPTICS .................................................................................................................................................27

4.7 SOFTWARE.......................................................................................................................................... 29

5.0 TROUBLESHOOTING ........................................................................................................................ 1

5.1 OVERVIEW............................................................................................................................................. 1

5.1.1 Service Philosophy..................................................................................................................................1

5.1.2 Safety Precautions ..................................................................................................................................2

5.2 INTERIOR ACCESS & PART LOCATIONS.....................................................................................3

5.3 SERVICE MODE ................................................................................................................................. 12

5.4 FAULT ISOLATION............................................................................................................................14

5.4.1 TURN-ON AND SHUTDOWN FAULT ISOLATION ...................................................................... 15

5.4.2 "NO FAULT CODE REPORTED" FAULT ISOLATION ...............................................................15

5.4.3 "FAULT CODE REPORTED" FAULT ISOLATION .....................................................................15

6.0 SELECTED PARTS ................................................................................................................................ 1

8.0 SCHEMATICS AND DRAWINGS .................................................................................................... 1

1.0 GENERAL INFORMATION

1.1 USE OF THIS MANUAL

This manual contains service instructions for the Coherent VersaPulse Select series of Holmium:YAG surgical lasers. The content of this manual is intended solely for use by Coherent Medical Group Field Service Engineers and Coherent trained and certified customer technicians. Coherent, Inc. can not be responsible for service or repairs attempted by uncertified persons, and the use of this manual by such persons is prohibited.

This manual is to be in conjunction with the Coherent Operator Manual for the VersaPulse Select. The operator manual contains important information regarding instrument description, location of controls, specifications, and normal operating procedures.

As necessary, Coherent Medical Group Service Technical Support releases Field Service Bulletins for the Versapulse Select series. These bulletins supplement the information in this manual. As they are released, the bulletins become a part of this manual (Section 7).

1.2 CONVENTIONS USED IN THIS MANUAL

Within the text, logic signals that are active low ("notted") will appear inside of slash marks, as illustrated below.

/BRHOK/

These signals are "active", or true, when the logic level is low. When the logic signal /BRHOK/ is low, the BRH loop is "OK" (complete). When the logic signal /BRHOK/ is high, the BRH loop is not OK (open).

In most of the schematic diagrams such signals are indicated by the more usual solid line above the signal name, as illustrated below.

BRHOK

The schematics in this manual do not include individual numbers for the logic elements or operational amplifiers within a single component. For example, U1 below contains two operational amplifiers. The top op amp would be referred to as U1-1 ( its output is pin 1), and the other would be referred to as U1-7.

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1-1

1.3 SERIAL NUMBERS

Serial numbers for the Versapulse Select are in the format,

MYPHWVXXXX

where M is the month produced

Y is the last digit of the year produced

P is a number indicating maximum system power

H is the number of laser heads installed (1, 2, 3, or 4) W is a number indicating the mix of rods installed

V is a number indicating power supply configuration

XXXX is the number of the laser built

W: 1= Holmium only

2= Erbium only 3= Nd:Yag only 5= Nd/Ho combo

(a is January, b is February, etc..)

(4 is 1994., etc..)

(6=60w, 4=45w, 3=30w)

(See Below)

(1= 208VAC single phase)

(0001, 0002, etc..)

GENERAL INFORMATION 1-2

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2.0 INSTALLATION

2.1 INSTALLATION INSTRUCTIONS

These installation instructions are provided for use by Coherent Service Engineers who have completed certification service training on the VersaPulse Select. Installation by untrained persons is a potential hazard to the person or persons doing the installation, others present, and to the equipment itself. In addition, improper installation is a potential hazard to the user, persons present during use, and patient.

Perform the following steps to install a VersaPulse Select system.

1. Check for proper site set up. This includes proper AC service and adequate space for the console.

AC power configuration: The VersaPulse Select requires 220 VAC ±10%, 50/60 Hz, 30 amp single phase electrical service. The power cord is a 26 foot cable with 3 conductors. A terminal board behind the right side cover allows for tapping of the isolation transformer to the setting closest to the incoming electrical service. The system can be hard wired to electrical service or installed to electrical service with a plug and receptacle. The plug and receptacle are shipped in the site preparation kit.

Console dimensions and weight: The console measures 39" l x 18" w x39" h. It weighs approximately 325 lbs. A minimum of 18" of air space is required around the unit to provide adequate cooling air circulation.

The system requires approximately 2.5 gallons of deionized water for its closed loop cooling system. The coolant must be added as described in this procedure.

Complete specifications for the VersaPulse Select are included in the VersaPulse Select Operator Manual. Contact Technical Support in Palo Alto, CA, if there are any questions concerning site preparation.

2.) Check the crate/carton for any shipping damage.

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CARDBOARD TOP COVER

STRAP

WOODEN RAMPS

CARDBOARD SIDE COVER

STRAP

FOAM

Accessories

Removable wooden ramp (2)

INSTALLATION 2-2

Front lifting bolts (2, 3/4ths)

LIFTING BAR (2)

As the bolts turn, the lifting bar is raised or lowered. The system ships with the lifting bar up. The bar must be lowered and removed, then the system is rolled down the wooden ramps to remve it from the crate base.

FIGURE 2.1 SHIPPING CRATE

WOODEN BASE

Rear lifting bolts (2, 5/8ths)

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The shipper is responsible for any damage to the system in shipment. If the crate/carton appears to be damaged, report the damage to the customer and shipper.

3.) Remove the console and accessories from the crate.

Refer to drawing 2-1. Remove the straps, remove the top cover, remove the side cover, remove the protective foam, remove the accessories box, then locate and remove the two wooden ramps stored in the base. Lower the lift plates (2) by turning the bolt at each end of each lift plate (5/8" and 3/4" bolts). Loosen the bolts all the way, then remove the bolts and lift plate. Remove the front fence from the base by removing the four wing nuts that secure it to the base. Install the ramps onto the base, then roll the unit down the ramps.

4.) Move the system to its installation location.

The VersaPulse Select rolls best when pushed from the front handles. The front wheels swivel, the rears wheels do not.

6.) Open/remove covers and do a visual inspection of the interior.

Refer to Section 5 for information on removing the covers. Open the front cover, then remove the top and two side covers. Inspect the interior carefully for loose or broken electrical connections, loose or broken plumbing connections, or any indication of shipping damage.

7.) Set up for site AC.

Measure the voltage of the site electrical service at the point where the VersaPulse Select will be connected. The three connections include an earth ground and two hot mains. Measure line voltage across the two hot mains. Mains voltage must be between 200 and 240 VAC, 50/60 Hz. Confirm that the circuit is rated for 30 amps.

The isolation transformer has two secondaries: one operates the turn-on circuitry and the other provides AC to the low voltage power supply, display power supply, fan and pump. These secondary loads (not the turn-on circuitry) are rated for 220 VAC supply input. The isolation transformer is tapped to allow a range of AC line inputs ( 200 to 240 VAC) to be stepped up or down to result in a secondary voltage at or near 220 VAC to these secondary loads. The various taps on the isolation transformer are wired out to terminal board TB1 on the right side on the system. The tapping is done by changing the connections at the terminal board.

POWER CORD

TB1

MAINS TO CIRCUIT BREAKER

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MAINS (from F1)

MAINS ( from F2)

120

100

ISOLATION XFORMER (primary)

EARTH GROUND TO GROUNDING STUD

FIGURE 2-2 TB1 TAPPING

INSTALLATION

2-3

8.) Connect to AC service.

CAUTION: Once connected to site electrical service lethal voltages are present inside the unit. The AC power is present at the circuit breaker, main contactor and isolation transformer. In addition, the isolation transformer secondary outputs are hot. Review and understand the safety subtopic in Section 5 before proceeding.

The system can be hard wired to electrical service, but is more typically connected by a plug to an electrical outlet.

If the system is to be hard wired, the customer must provide an electrician to wire the cord end into the electrical service outlet.

If the system is to be plugged into an electrical receptacle, the appropriate receptacle should already be installed by the customer's electrician. The installing engineer connects the plug to the end of the VersaPulse Select electrical cable.

9.) Add coolant.

Add coolant (deionized water) to the fill reservoir. The coolant will drain out of the fill reservoir and into the main reservoir. The system uses approximately 2.5 gallons of coolant. Most of the coolant can be added at this time - until the fill reservoir level stays up. The system coolant level will be "topped off" after the system is turned on (in a later step).

9.) Initial power application.

CAUTION: Once the circuit breaker is turned on lethal voltages are present throughout the system.

With the side covers still removed, turn on the electrical service and turn on the circuit breaker on the VersaPulse Select. Wait a few minutes, observing for any indication of failure of mains or turn-on components.

10.) Initial turn on.

CAUTION:

• The system will fire during the turn-on sequence if SW3 (Autocal) on the CPU PCB is up and the BRH plug is installed. Only those persons required should be present during this portion of the installation

• The cooling fan blades are not covered. The fan is located on top of the heat exchanger. It operates whenever the system is turned on. Keep tools, system parts and body parts clear of the fan blades.

Turn the keyswitch to the START position, then release it to the ON position. The system will go through its start up sequence. Observe for normal start up, and for any indication of leaks in the cooling system.

INSTALLATION 2-4

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11.) Add coolant.

With the system turned on, top off the fill reservoir. Cycle the machine off and on several times, adding coolant as necessary until the fill reservoir level stays up to approximately half full as the system runs.

12.) Operational and Safety Checkout.

Attach a test fiber, remote interlock plug, and footswitch, then check system operation as follows:

a.) Footswitch, remote control (if included) and remote interlock plugs connect properly to jacks.

b.) Fiber attaches to the fiber port.

c.) Touch screen display matrix is operating properly.

d.) Touch screen inputs are functional.

e.) Remote control (if installed) display and input buttons are functional.

f.) Aiming beam responds to off, low, medium, and high settings.

CAUTION: The remaining operational tests include firing the system and attempts to fire the system with one disabling condition. Select a low power setting and direct the test fiber output into a calibrated power meter.

g.) Fire into the meter for several seconds, noting the power reading on the meter.

i.) Confirm that the total energy display value has incremented, then confirm that the value clears back to zero when RESET is touched.

j.) Disconnect the footswitch and confirm that the "ATTACH FOOTSWITCH" message appears on the display.

k.) Reconnect the footswitch, then disconnect the fiber and confirm that an "ATTACH FIBER" message appears on the display. Depress the footswitch and confirm the system will not fire.

l.) Reconnect the fiber, then disconnect the remote interlock plug and confirm the " REMOTE INTERLOCK" message appears on the display.

m.) Reconnect the remote interlock plug, then go to STANDBY. Depress the footswitch and confirm the system will not fire.

n.) Pull the blast shield out, then confirm the "REPLACE BLAST SHIELD" message appears on the display. Depress the footswitch and confirm the system will not fire.

o.) Reinsert the blast shield.

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13.) Confirm the power calibration.

Connect a good test fiber onto the fiber port and direct the fiber output towards the head of your calibrated power meter, then, for each operating point, fire the system into the meter, confirming that displayed power remains within ± 10% of the power indicated on the meter (typically, the power calibration will be much more accurate than ±10%). If the power calibration is not better than ±10% at all operating points, refer to Section 3 for instructions on system calibration.

14.) Check the fiber focus using a test fiber.

Two test fibers are shipped with the system. Check the fiber focus as described in Section 3, topic 3.2, step 3.

15.) Replace all covers and prepare the system for demonstration to the customer.

16.) Demonstrate the system installation to the customer.

17.) (for U.S. Field Service) Fill out and mail the "self mailer" installation quality audit report.

INSTALLATION 2-6

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3.0 CALIBRATION & ADJUSTMENT

3.1 OVERVIEW

This section includes a System Checkout Procedure, Energy Monitor Calibration Procedure, a YAG Channel Adjustment Procedure and an Aiming Beam Adjustment Procedure. The procedures assume the reader has successfully completed a Coherent service training course on the Versapulse Select series.

The System Check Out, Topic 3.2, is an operational check of the system. It confirms that the system turns on properly, responds properly to operator inputs, provides the full range of pulse energies and pulse rates, delivers average power within ±10% of the displayed average power, delivers the multiplexed YAG beam into the center on an attached fiber, and provides an adjustable aiming beam through the fiber. It also checks system coolant level and consumables (i.e., air filter, DI filter and particulate filter).

The Energy Monitor Calibration Procedure, Topic 3.3, calibrates the voltage output of the three energy monitor circuits to the field service engineer's calibrated power meter.

The YAG Channel Adjustment Procedure, Topic 3.4, is done when the System Check Out Procedure indicates a problem with one or more of the YAG channels. It provides adjustment procedures for the channel cavities and relay optics.

Aiming Beam Adjustment, Topic 3.5, provides information on adjusting the aiming beam optics to get the aiming beam out through the fiber. See Section 6 for required tools.

3.1.1 Safety Precautions

Lethal voltages and laser emission are the primary dangers to the servicing engineer. In addition to the general safety precautions which always apply when working on electronics and lasers, the servicing engineer must be aware of the following specific precautions:

Only Coherent certified VersaPulse Select Service Engineers should attempt any service on this system.

Even with the keyswitch and the breaker in the "OFF" position there are potentially lethal voltages present inside the console. Always disconnect the main electrical service before working on the console.

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Storage capacitors inside the system are capable of holding a lethal charge, even after power has been removed from the unit. A charge level indicator bulb located on the PFN PCB mounted across

the top of the main storage capacitor flashes at a rate proportional to the level of charge on the main charging capacitor. Do not rely on this indicator to determine that the main charging capacitor has been discharged. Before contacting the main charging capacitor, disconnect the system from primary power and use a shorting probe to discharge the capacitor to ground.

Do not touch the YAG Cavity Module when the system is on - IT IS A SHOCK HAZARD. The YAG Cavity Module is electrically isolated from the chassis and can be at a voltage potential much higher than ground.

Whenever the footswitch is pressed a single pulse is fired immediately, before the shutter opens, to dump any charge remaining on the charge capacitor. The laser cavity that fires is the one directly

opposite the one that the servo mirror is pointing towards. The energy is dependent upon how much charge remains on the capacitor. Since the relay mirror is not directed towards the channel, the beam will be directed away from the first turning mirror (usually towards the mounting screws for the plano mirrors on the OC wall.

The Ho:YAG, Er:YAG and Nd:YAG laser light is invisible to the human eye. Because the YAG laser energy can not be seen, there is no visible indication of the primary or reflected beam. Eye protection that attenuates the Ho:YAG, Nd:YAG and Er:YAG wavelengths to a safe level must be worn by all persons in the area of the laser system, whenever the laser is being serviced.

The YAG laser light and its reflections are potential burn hazards and can ignite flammable materials. Use extreme caution when operating the system with covers opened or removed. The

covers contain the beam and reflections safely within the console. Only those persons required should be present during servicing, and eye protection that safely attenuates the Ho:YAG, Nd:YAG and Er:YAG wavelengths must be worn by all present.

The Ho:YAG, Er:YAG and Nd:YAG laser light and its reflections are potential hazards to the eye.

Use extreme caution when operating the system with the covers opened or removed. The covers contain the beam and reflections safely within the console. Only those persons required should be present during servicing and eye protection that safely attenuates the Ho:YAG, Er:YAG and Nd:YAG wavelengths should be worn by all those present.

3.2 SYSTEM CHECK OUT

This system check out confirms that the laser is functioning properly.

1.) Open the front door and defeat the door interlock, then turn the system on and allow it to go through autocalibration. After autocalibration is completed, place the system in service mode.

If the system fails to pass autocalibration, there is something wrong; continue on to step 2 to gather more information about why the system failed autocalibration.

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2. Check rod calibration values.

Go to the second service screen and note the cap voltage values displayed for each of the four channels at minimum (low point) and maximum (high point).

The HVPS maximum output is 1500 VDC, so each rod must be capable of making its maximum pulse energy (high point) at less than 1500 VDC. Typical values at high point are from 1280 to the low 1400's. Typical voltages for low point are in the 700 to 900 VDC range.

For Nd:YAG the typical values at high point are from 500 to 800 VDC, and typical low point values are from 200 to 400 VDC.

As the rod temperature increases (during use), its output will tend to drop off for a given cap voltage. The software compensates for this effect, so as the rod temperature increases, it is normal to see the cap charge voltage required at a particular pulse energy increase. Since the system goes through its autocalibration at turn on, when the rods tend to be cooler, the cap charge voltages found during autocal will tend to be lower than those that might be required during sustained, high duty cycle operation. Thus, a channel with a cap charge voltage in the mid to high 1400's @ 2.8 Joules at turn on may require a cap charge voltage higher than the HVPS can provide to make 2.8 Joules during operation.

If the system has failed to complete autocalibration or channel performance appears poor, perform the YAG Channel Adjustments (Topic 3.4).

3. Inspect debris shield and clean/replace as required.

4. Check the power supply voltages, coolant temperature and coolant conductivity.

5. Check the fiber focus using a test fiber.

If the system passes autocalibration and channel performance appears normal (service screen min/ max cap charge values are good), check for proper alignment of the beam into the fiber. This is done using a special test fiber (0621-675-01). The fiber proximal end is coated with a red ink (Berol 8800 red marker) that records an impression of the YAG beam footprint where it enters the end of the fiber. The laser is fired into the test fiber, then the fiber end is examined using a hand held 100X microscope. A good alignment will result in a "concentric" footprint, i.e., the footprint will be approximately centered in the fiber core and be well away from the cladding that surrounds the fiber.

a.) Install a test fiber in the 100X fiber examination microscope and examine its surface to confirm that it is unused.

b.) Install the test fiber at the fiber port, then turn on the system and go to service mode.

c.) Turn on all the rods, select 850 cap volts and a pulse rate of 20 Hz.

d.) Fire the laser for approximately one second.

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e.) Remove the fiber and examine it in the microscope. The burn and cladding will be easily visualized if the other end of the test fiber is pointed towards a light source. The burn should be approximately centered in the fiber optic and be well away from contact with the fiber cladding, as shown in the drawing below. If the system fails this check, perform the YAG Channel Adjustments (Topic 3.4.).

Cladding

Core

Footprint

ACCEPTABLE

Examining the test fiber end with the 100x microscope - The footprint will not always be circular, but it should be approximately centered in the fiber and away from contact with the cladding.

FIGURE 3.1 EXAMINING THE TEST FIBER BURN

* If spot size is large, check individual YAG channels for proper alignment. Spot size should be less than 210 µm in diameter and no closer than 70 µm from the cladding.

6. Confirm the calibration

Once the system passes steps 1 through 3, attach an Infratome fiber (nonsterile fibers for service purposes are available through Technical Support) to the fiber port and direct its output into a calibrated power meter. Go to user mode and fire the system to confirm that the measured power (as seen on the power meter) is within ±10% of displayed average power across the range of pulse energies and pulse rates.

7. Check consumable parts. Replace as necessary.

NOT ACCEPTABLE

Check/replace the air filter. The air filter is mounted on the bottom of the system, held in place by a removable bracket. A dirty filter should be cleaned or replaced.

Replace the DI filter after 6 months of use, or when the system has coolant conductivity faults.

Check/replace the coolant particulate filter. Replace the filter when it is visibly discolored.

8. Perform functional and safety checks.

a.) Attach a fiber.

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b.) Confirm that the aiming beam is visible at the fiber output and that the aiming beam intensity properly responds to touch screen intensity control.

c.) Place the system in STANDBY, then depress the footswitch. Confirm the system does not fire.

d.) Go to READY and fire the system a number of times, verifying that the system displays the cumulative energy. Stop firing, then press "clear" and verify the counter returns to zero.

e.) Unplug the footswitch and verify the system goes to STANDBY and displays "Attach footswitch".

f.) Open the front door and verify the system shuts down. Defeat the interlock and confirm that the system turns back on.

g.) Remove the fiber optic. Verify that the system goes to STANDBY and "Attach fiber" is displayed. Replace the fiber optic and verify that the fault clears.

h.) Remove the blast shield. Verify that the system goes to STANDBY and "Install blast shield" is displayed. Replace the fiber and confirm that the fault clears.

i.) Check the operation of the keyswitch. It should turn the system on, turn the system off, and only be removable when the system is switched off.

j.) Confirm that the emergency off button shuts the system down.

3.3 ENERGY MONITOR AND AUTOMATIC LASER CALIBRATION

The energy monitor calibration adjusts the three energy monitor circuits to output 2.2 volts per Joule of energy as measured on a calibrated power meter at the output of an attached fiber. The automatic laser calibration (also referred to as "autocalibration" and "autocal") is run to allow the system to determine and store the capacitor voltages required to provide the maximum and minimum pulse energies for each rod.

1. Set up.

Open the front door of the VersaPulse Select and defeat the door interlock. Connect a known good test fiber to the fiber port and direct its output into a calibrated power meter. Connect an oscilloscope probe to CPU PCB TP2 (ENERGYI).

2. Turn on the system and go to service mode.

3. Turn off three rods, leaving one on. Select 40 Hz, then go to READY.

4. Adjust the cap voltage for a fiber output of 10 watts (1 Holmium head).

Fire the laser into the power meter, adjusting cap voltage up/down to get 10 watts of average power at the power meter. Once the charge voltage is set to provide a consistent power meter reading of 10 watts, stop firing and leave the cap charge at that setting.

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The system software has a 2.2 volts/Joule conversion factor written into it, so the energy monitor circuit must be calibrated to output 2.2 volts for a 1 Joule pulse. With 40 Hz selected, but only one rod on, the actual pulse rate will be 40/4 = 10 Hz. Since 1 Watt= 1 Joule/sec, 10 Watts = 10 Joules/ second,i.e. each pulse is 1 Joule.

5.) Calibrate ENERGY II.

Attach the scope probe to TP3.

Fire the laser, adjusting CPU PCB R8 to adjust the amplitude of the positive pulses on the oscilloscope screen to approximately 2.22 volts (the pulse will be about 2 mseconds in width, with a relatively "square" profile). Once the pulses are of the correct amplitude, release the footswitch.

6.) Calibrate ENERGY I

Move the probe to TP2, then adjust as in step 5 above, using CPU PCB R7.

7.) Calibrate ENERGY III

Move the probe to TP4, then adjust as in step 5 above, using CPU PCB R9.

8.) Turn all the rods back on, then confirm the calibration.

Turn the system back on (CPU PCB SW3 in its up position so the system will go through its autocalibration), then fire the laser into the power meter across its range of operating points, confirming that delivered power as measured by the power meter is always within ±10% of selected power.

3.4 YAG CHANNEL ADJUSTMENTS

When properly adjusted the YAG channel will meet each of the following three criteria.

•␣The cavity HR will be positioned to direct the YAG output to the center of the first relay mirror, and the cavity OC will be positioned to provide maximum power for that HR position.

• The first relay mirror and second (plano) relay mirror will direct the YAG energy off the two folding mirrors so that it is centered through the wedge optic apertures and centered into the proximal end of the fiber.

• Each YAG beam will be coaxial with the other YAG channels, confirmed at the second wedge optic aperture and at the fiber port.

The adjustment procedure for a single channel follows. The procedure is a complete check out and alignment for a single channel. The procedure is meant to be done in the order given, from beginning to end.

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It may often be appropriate to do less than the complete adjustment, but in such a case the field service engineer must consider the possible effect of doing only a portion, i.e., the adjustment may have an effect on some other portion of the alignment. As an example, If a single channel is only slightly out of center at the fiber port, it can usually be corrected by simply adjusting the first relay mirror (using the fiber detector signal) and then confirming the adjustment using a test fiber burn and second wedge optic burn.

When replacing a damaged optic, it should not be necessary to do the entire procedure - try to bring the system back into alignment by just adjusting the optic that was replaced.

3.4.1 Making Test Burns

(Refer to figures 3.2 and 3.3) Checking out and aligning the YAG channels requires making burns on photopaper to check alignment. The Alignment Aperture and Cross Hair Aperture are two special purpose tools used when making burns.

In general, when making burns, lower pulse energies and fewer total pulses are better. As the total energy into a burn increases, the footprint becomes "blurred". In some cases it will be necessary to get a "multiplexed footprint", i.e., the paper is burned by more than one channel, allowing the YAG beam positions to be compared. In other cases a single channel burn will be required. The service engineer can select the channels to be fired, a cap charge voltage and a pulse rate at the service screens. Setting a lower pulse rates allows the footswitch to be operated to obtain just a single pulse from a channel, or from each selected channel.

The alignment aperture is used to center the YAG beam(s) in front of the second wedge optic. It holds a piece of burn paper (covered on both sides with plastic to contain splatter). A good burn will fall inside the aperture (the aperture will not clip the beam). The tool is keyed with two small posts that fit into holes on the face of the second wedge optic housing block. To use the aperture, slide burn paper and plastic in through the side, then insert it on the second wedge optic housing.

The cross hair aperture is used to align an individual cavity (OC and HR) into the center of the first relay mirror. To install it, the first relay mirror mount is removed, then the aperture slides into a hole in the wall directly behind the spot the channel first relay mirror was mounted (insert from the outside of the wall, so that it is further from the channel OC). The aperture has two small wires running across it that block a small portion of the beam (perpendicular to each other and crossing in the center of the aperture). The resulting burn will have the cross hairs superimposed on it. The cavity optics are adjusted to center the burn in the cross hairs.

3.4.2 Adjusting the YAG Channel Optics

(Refer to figure 3.4) The channel HR, OC and relay mirrors all have the same basic adjustment mechanics. The mirror is held in a mirror mount by a metal retainer. The mount attaches to one of the optics bench walls by a single mounting screw with spring. The spring pulls the mount towards the wall - two adjusting screws and a ball bearing hold the mount out away from its mounting surface against the tension of the spring. One adjusting screws provides horizontal movement and the other provides vertical movement.

A locking nut is threaded onto each adjusting screw. To unlock the screw for adjustment back the locking screw away from the collar. Once adjustment is complete, lock down the adjustment screw by turning the nut down against the collar. As is common in such mechanical lock down set ups, the locking down process will change the adjustment a bit, so use the locking down to bring the optic to its optimum position. It is best to use the hex wrench to hold the adjusting screw in place while tightening down the locking nut with the box end wrench. The

adjusting screws require a 7/64th hex head wrench. The locking nuts require a 7/16th box end wrench.

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The channel HR and OC must first be aligned to each other through the length of the YAG rod in order to achieve lasing. Once the two mirrors are aligned to provide a usable output (will make a burn on photopaper), the two optics are adjusted together to "walk" the YAG output so that it is centered in the first relay mirror. Finally, the HR is adjusted to peak the power out of the cavity into the center of the first relay mirror.

The channel first and second (plano) relay mirrors are adjusted to center the channel YAG beam through the wedge optics and into the center of the fiber port. The first relay mirror is the fine adjustment (it is concave, and provides less positional change to the beam downstream at the fiber port). The second relay mirror is a gross adjustment, it moves the beam much more than the first relay mirror. In general, unless the beam is grossly out of center at the second wedge aperture, the second relay mirror should not be adjusted.

There are also two turning mirrors that steer all the YAG channels off the servo mirror down towards the fiber port. These mirrors do not normally require adjustment. Obviously, adjusting one of these mirrors will affect all four YAG channels. The adjustment and mounting scheme is the same as that for the channel optics.

3.4.3 YAG Channel Check Out and Adjustment Procedure

1. Remove the optics bench cover.

2. Examine the optics for any visual sign of damage. Replace damaged HR, OC, or Relay mirrors.

To replace a channel relay mirror, HR, or OC, first remove the mirror mount by carefully removing the mounting screw (it has a spring around its shaft to place tension on the mount) while supporting the mount. Once the mount is free, set it down face up and remove the retainer (held in place by three hex head screws) that hold the optic. The old optic can then be removed and the new optic inserted (five ball bearings inside the mounting hole center the optic in the hole). Reinstall the retainer, then the mirror mount. Note that the mount should return to its former position, since the adjustment screws were not moved.

3. Examine the end of the rod for visual damage.

The rod will be illuminated by the flash lamp when the unit is on (if not, the flash lamp has failed or the simmer supply circuitry has a problem). Replace a damaged rod or failed flash lamp by replacing the brick assembly.

4. Center and peak the cavity output into the first relay mirror.

When the cavity OC and HR are correctly aligned the YAG beam will be centered in the relay mirror directly across from the OC, and the cavity power output will be peaked.

a.) Remove the first relay mirror mount and install the cross hair aperture (as described in

3.4.1).

b.) Make a burn (single channel) through the cross hair aperture onto a piece of burn paper.

c.) Examine the burn to determine if the YAG beam is centered.

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The burn should be centered over the cross hairs. If not, adjust ("walk" as described in the following subparagraph) the OC/HR positions to bring the burn into center, rechecking as necessary as in step "b" above. Continue adjustment until the burn footprint is centered in the cross hairs.

"Walking" the beam refers to the method of adjusting the OC and HR in the same direction and distance, so that the two mirrors remain in the same orientation with each other, but are brought to a new orientation with respect to the rod. Each mirror mount has a horizontal and a vertical adjustment screw. For example, to walk the beam "up" with respect to the hole, the OC vertical adjustment would be turned in, then the HR vertical adjustment would be turned out the same amount (don't be fooled as to the direction to turn the adjustment screw by the fact that the two screws are mounted in opposite directions - one screw is being turned in and the other is being turned out, but because the screws are mounted in opposite directions the screws rotate in the same direction).

d.) Once the burn has been centered in the cross hairs, remove the cross hair aperture and place the power meter head behind the hole, so that the YAG energy through the hole will strike the power meter head. Fire the laser into the head and adjust the OC to peak the cavity power output.

e.) Replace the cross hair aperture and recheck the beam centering through the hole as in step "b" above. Some slight readjustment of the HR may be necessary to recenter the burn in the cross hairs.

f.) Repeat steps "d" and "e" until the power is peaked and the burn is centered in the cross hairs, with the HR and OC adjustment mechanisms locked down.

5. Center the YAG beam through the wedge optics and into the fiber port.

For each channel, two optics are adjusted to position the YAG beam down the intended optical path into the center of the fiber; the first relay mirror and the second (plano) relay mirror.

The second relay mirror seldom needs to be adjusted. It provides a much wider range of movement of the beam than the first relay mirror. The four second relay mirrors are all mounted on the cavity OC wall. Although the second relay mirror mounts are shaped differently than the other channel mirror mounts, the mounting and adjusting hardware is the same - each is held in place by a spring loaded mounting screw and each has a horizontal and vertical adjusting screw with locking nut.

The first relay is normally the only adjustment needed to get the YAG beam centered through the wedge optics and centered into the fiber port.

a.) Use the test aperture to check the YAG channel centering into the second wedge optic opening. Examine the burn and proceed as follows:

An acceptable burn is to be centered and no clipping should be seen. If the burn is acceptable, go on to step "b" below.

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An unacceptable burn will be well off center (more than a fourth of the burn is clipped) In this case, the second relay mirror must be adjusted to bring the YAG beam closer to the center of the aperture as described below.

Make a slight adjustment to the second relay mirror, then check the result by making a burn on photopaper at the second wedge optic. Because a number of burns may be required to complete the adjustment, using the test aperture can slow things down (the aperture would have to be reloaded with a clean piece of paper after each shot). As an alternative, find a second channel that is already centered in the aperture, and then use the service screen to turn that channel on as well as the channel to be adjusted. When the laser is fired the two channels will each fire in turn. Instead of using the aperture, make the burns on a larger piece of paper held in front of the aperture, moving to a clean spot for each check. The known good channel becomes the reference adjust the second relay mirror for the channel out of adjustment until the burn footprints are on top of each other. Once the channel is roughly positioned over the aperture, lock down the mirror and go on to step "b" below.

b.) Align the YAG beam into the fiber port using the Fiber Alignment Detector Box.

Insert the service attenuator into the beam path (switch is on the Shutter PCB). Connect the fiber alignment detector box to the fiber port and oscilloscope. Select a 40 Hz pulse rate (really 10 Hz since only one channel is on), then adjust as indicated in the subparagraph below.

Fire the laser while observing the oscilloscope. Each laser pulse will produce a square pulse on the screen (≈ 2 mseconds pulse width). Make slight adjustments to the channel first relay mirror to peak the amplitude of the pulses on the oscilloscope.

c.) Check the burn into the second wedge optic using the test aperture.

The beam must be unclipped. If not, repeat steps "a" and "b" above until both pass with the adjustments mechanisms locked down.

6. Do a burn footprint into the test aperture with all four channels turned on.

The resulting burn footprint should be circular in shape and contained in the aperture (no clipping).

7. Perform the system checkout as outlined in Topic 3.2

3.5 AIMING BEAM ADJUSTMENT

The aiming beam can be adjusted by repositioning the aiming diode mount or by adjusting the position of the folding mirror (the mirror that directs the aiming beam onto the beam combiner). In either case, observe the aiming beam output from the fiber and adjust to obtain a full spot of bright red light (no doughnut).

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FIGURE 3.2 : USING THE TEST APERTURE

Insert the test aperture here, in the mounting hole for the second wedge optic, inserting the two key posts on the aperture into the two holes on the mount.

FIGURE 3.3: USING THE CROSS HAIR APERTURE

Remove the channel first relay mirror mount, then insert the cross hair aperture in the hole from the back (further away from the OC).

Towards fiber

Burn paper

Towards laser

Clear plastic over burn paper, slides into slot on the test aperture.

CROSS HAIR APERTURE

BURNS THROUGH THE CROSS HAIR APERTURE:

Out in vertical and horizontal.

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Servo Mirror

Out in vertical Properly

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SIDE VIEW

LOCKING NUT

ADJUSTING SCREW (typical, 2 per mount)

MOUNTING SCREW (one per mount)

Ball bearing is the pivot point about which the optic mount is moved by the two adjusting screws

Mounting Screw threads into this hole.

INSIDE SURFACE (towards wall)

MOUNTING

WALL

OPTIC RETAINER

OUTSIDE SURFACE (away from wall)

Rounded end of the adjusting screws contact the optic mount here.

MIRROR

MOUNT

MIRROR

FIGURE 3.4: ADJUSTMENT AND REPLACEMENT OF THE CHANNEL OPTICS

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3.6 PERIODIC MAINTENANCE REQUIREMENTS

The systems require the following periodic maintenance:

ANNUALLY (AS REQUIRED):

Perform a general visual inspection of the electrical, mechanical, and optical components.

Check/clean the air filter. The air filter is mounted on the bottom of the system, held in place by a removeable bracket. A dirty filter should be cleaned (vacuum) or replaced if damaged.

Replace the DI cartridge after 12 months of use, or when the system has coolant conductivity faults.

Check/replace the coolant particulate filter. Replace the filter when it is visibly discolored.

Check the blastshield optic and replace if required.

Cooling system level check. The cooling system fill reservoir is located on the top of the laser. The top cover must be removed in order to gain access to the reservoir. Use deionized water, with the system running, to bring the coolant level up to half full in the fill reservoir. Cycle the system off/on several times, adding deionized water as necessary until the level stays up.

Calibration and adjustment:

Energy monitor and automatic laser calibration (see Section3).

If the lamp voltage exceeds 750 VDC for Nd:Yag or 1450 VDC for Ho:Yag replace the flashlamps as required.

Yag channel adjustments (see Section3).

Check alignment (especially at the transimpedance amp) to fiber.

Perform the Operational and Safety Checkout (see Section 2.1 step 12).

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4.0 THEORY OF OPERATION

4.1 INTRODUCTION

4.1.1 Operational Overview

The Versapulse Select family of Holmium YAG laser systems is designed for use in surgical applications. The treatment laser delivers pulsed 2100 nm wavelength energy (invisible) through a user attached disposable delivery fiber in response to the depression of an attached footswitch. The pulses continue until the footswitch is released. A diode laser provides a visible (red, 650 nm) aiming beam. An equipment description, specifications and detailed user operating instructions are included in the Versapulse Select Operator Manual.

A key is required to turn the system on. At turn-on the system undergoes a series of self tests (approximately 30 seconds), then, if no malfunctions are detected during the self tests, goes to its STANDBY condition. If the

self testing process detects any malfunction, an error message will be displayed and the system will not be enabled until the fault condition clears.

Once the unit is in STANDBY the user selects the desired operating parameters through a touch screen display, or on a wired remote control (available as an option). Controls include aiming beam intensity, pulse energy and pulse rate. Selections are displayed on the screen.

Aiming beam intensity can be turned off or adjusted for high, low or medium.

Pulse energy and pulse rate combine to determine the average power.

(ENERGY/PULSE)*(PULSES/SECOND) = Average Power in Watts

Pulse energy is adjustable, in increments, from .5 to 2.8 Joules. Pulse rate is adjustable, in increments, from 5 to 40 Hz. The combination of pulse energy and pulse rate define an operating point. Not all combinations of pulse energy and pulse rate are valid, and the operating points available vary with the different Versapulse Select models available. Consult the Operator Manual for detailed information on the operating points for a particular model.

A total energy display with a clear function allows the user to keep track of the total energy used from the last time the display was cleared.

A delivery system fiber is attached to a fiber port on the front of the system console. The delivery fiber is a consumable item. It comes in a number of styles to meet the requirements of various applications (angled, etc.). The system will not fire without a delivery fiber attached.

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Once the system operating parameters are selected, the user selects the READY mode, positions the fiber output at the treatment site, then depresses the footswitch to deliver treatment pulses at the rate and energy selected. The treatment delivery will continue until the footswitch is released. Note that the Versapulse Select does not require any ramp up firings before delivering treatment pulses - the shutter opens and treatment delivery begins without delay.

Fault monitoring continues for as long as the system is turned on, and any detected fault is reported on the touch screen.

An emergency off button is located on the console next to the key switch. Depressing it will turn the system off.

4.1.2 Functional Overview

There are several models of Versapulse Select in (or planned for) production. The primary difference between the models is the maximum average power available. The Versapulse Select can hold up to four Ho:YAG rods. The maximum average power the system provides is determined by the number of rods used. The lower power systems do not have all four rods installed. The remainder of this subtopic will describe the Versapulse Select with four rods installed. Lower power systems operate in the same manner, but with fewer rods.

Refer to the Versapulse Select Simplified Block Diagram. The Versapulse Select has four identical Ho:YAG cavities arranged in a 2x2 matrix. Each cavity includes its own rod, flash lamp, high reflector, output coupler and set of two relay mirrors. The rods are operated sequentially - never together - thus each rod is capable of producing the maximum selectable pulse energy (2.8 Joules). Each rod delivers every fourth pulse. This sequential firing allows the Versapulse Select to provide four times the pulse rate as could be provided by a single rod, increasing the maximum average power available by the same factor (four).

For example, at the 40 Hz pulse rate, each rod is operating at 10 Hz, and is producing 1/4th of the average power. As a result, the Versapulse Select provides higher selectable pulse rates and higher average powers without requiring the extreme rod cooling as would be required in a single rod system at the same operating point.

The use of multiple heads results in a number of advantages over previous surgical Ho:YAGs: Versapulse Select is smaller and lighter; it has a much simpler and more reliable cooling system; and it can operate at much higher pulse rates, resulting in higher average powers.

While the use of multiple heads provides all the above mentioned user advantages, it also results in several design challenges:

Flash lamp supply switching - The Versapulse Select uses a capacitor discharge to supply the current required to flash the lamps. The voltage level of the charge on the capacitor determines the amount of light energy out of the lamp, and therefore the pulse energy out of the rod. A vendor supplied high voltage power supply charges the capacitor between pulses. Using four heads requires a method of switching the charging supply current between the four flash lamps. The Versapulse Select uses SCR's to switch the charging supply current between the four heads.

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Multiplexing the beams - Merging the four Ho:YAG beam paths requires a more complicated optical scheme. Versapulse Select uses a servo positioned rotating mirror to assemble the four Ho:YAG beams into a single beam path. The servo system must re-position the mirror between pulses, pointing the mirror towards the head that will be flashed.

Control - In general, the microprocessing demands of the Versapulse Select are greater than that of a single head system. The Versapulse Select uses two Motorolla 68000 microprocessors - a main processor and safety processor.

For the purposes of this discussion, the Versapulse Select is divided into the following functional subsystems. The remaining topics in this section provide a detailed description of each subsystem.

Power Switching, Conditioning, Distribution (4.2) - Provides switching and conditioning of the primary power input, converts the AC line voltage to DC voltages used within the system and distributes the various voltages throughout. It includes the turn-on and turn-off circuitry. It does not include the high voltage power supply (HVPS).

Cooling (4.3) - The cooling system removes heat from the Ho:YAG cavities and two beam dumps. It is a closed loop distilled/de-ionized water system including a pump, reservoir tank, fill tank, heat exchanger, variable speed fan, D/I filter, flow switch, temperature sensor and conductivity sensor.

Control Electronics (4.4) - The control electronics executes the software instructions to provide overall control of the Versapulse Select. It includes a main processor (Mµp) and independent safety processor (Sµp), associated circuits (DIO, ADC, DAC), a touch screen display, and a number of optoelectronic and electro-mechanical devices.

Flash Lamp Supply Circuits (4.5) - The flash lamp supply starts and simmers the four flash lamps, responds to control electronics commands to charge the main charging capacitor and to discharge the capacitor through the selected flash lamp. It includes the HVPS, the main charging capacitor, isolated trigger circuits, lamp select SCR's, electric field transformer, flash lamps and the simmer supply.

The flash lamps are simmered at a low current between flashes (the rods are not simmered - the flash lamps are kept on in order to allow SCR turn on). The simmer power supply provides the simmer current to each of the four lamps and supplies a transformer used to generate an electric field to ionize the flash lamps.

The Ho:YAG pulses of laser energy are controlled by command signals from the control electronics. Prior to each pulse the control electronics sends a charge command to the HVPS. The command indicates the voltage level to which the main charging capacitor is to be charged. The higher the capacitor charge voltage, the more energy will be produced in the laser pulse. The HVPS charges the capacitor to the indicated voltage then sends a charge complete signal back to the control electronics. To get a pulse of treatment energy the control electronics triggers the SCR for the cavity that has been selected for firing. The SCR turn-on creates a discharge path for the main charging capacitor through the selected flash lamp.

Optics (4.6) - The optics include the portions of the system that operate on the Ho:YAG beams and/ or diode aiming beam. There are four separate and identical Ho:YAG cavities arranged in a 2 x 2 matrix. Each includes a rod, flash lamp, high reflector, output coupler, and two relay mirrors. The relay mirrors direct the Ho:YAG output from the OC towards the surface of a servo positioned mirror. The servo positioned mirror is used to multiplex the four separate Ho:YAG beams into a single beam path. The remainder of the beam path includes the following optical components.

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Folding Mirrors - 2 folding mirrors direct the beam output from the servo mirror towards the fiber focusing lens.

First Wedge Optic - The wedge optic front and back surfaces each reflect a small portion (≈.2%) of the YAG energy back towards an imaging mirror. The imaging mirror is positioned to direct these reflections upon two pyrodetectors mounted on the Single Solenoid PCB, one sample to each pyro. The pyro circuitry translates the energy sample into a voltage proportional to the energy of the Ho:YAG pulse.

Low Energy Attenuator - The LE attenuator is inserted into the beam path to allow the Versapulse Select to deliver a lower range of pulse energies. This function is currently used on dual wavelength lasers if holmium energy is less than .5 j or Neodymium power less than 25 W is selected.

Second Wedge Optic - A second wedge optic is required to check the power after the LP attenuator. Although two samples are reflected off the wedge, only one is used. An imaging mirror directs the sample towards a pyrodetector mounted on the Dual Solenoid PCB. The pyro circuitry translates the energy sample into a voltage proportional to the energy of the Ho:YAG pulse. The low power attenuator function is not implemented by current software.

Service Attenuator - The service attenuator is inserted into the beam path to attenuate the beam before it enters the fiber focus assembly. This prevents damage to the attached fiber alignment detector as the system is fired to do the fiber focus alignment. It is operated by a switch inside the unit accessible to the service engineer. The system will not operate in user mode if the service attenuator is left in the beam path.

Safety Shutter - Blocks the treatment beam path when de-energized.

Aiming Beam Diode, Folding Mirror, and Combiner Optic - Aiming beam is provided by a 650 nm diode laser. The user can select high, low, or medium intensity; or turn the aiming beam off. The folding mirror and combiner are adjusted to place the aiming beam coaxial with treatment beam.

Fiber Focus Lens - Focuses the beam into the end of the fiber.

Blast Shield - Protects the fiber focus lens from debris ejected from the proximal end of the fiber in the event of a fiber failure.

Delivery Fiber - A number of delivery fibers are available for use with the Versapulse Select, each providing features suiting it to certain applications, such as orthopedic, endoscope, laparoscope, laser assisted disk surgery, etc.. The fibers are designed for a single use and are not repairable.

Software (4.7) - Separate sets of instructions are provided for the main processor and safety processor, i.e., the two processors do not execute the same instruction sequence - the main processor is primarily involved with operating the system in response to user inputs, while the safety processor is exclusively involved with monitoring for and responding to any potential unsafe condition. The two software programs require inputs from the other, i.e., they are designed to run concurrently, and communicate back and forth through a shared memory. The software instructions are stored in EPROM's on the Controller PCB. Software upgrades can be accomplished by replacing the software EPROMs. Different software versions are required for different Versapulse Select models.

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4.2 POWER SWITCHING, CONDITIONING, DISTRIBUTION

4.2.1 Input Power

Refer to 8 - 2. The Versapulse Select operates off of 200- 240 VAC line voltage. The main circuit breaker is rated at 30 amps. The mains and ground inputs are wired into TB1. From TB1, the two mains run to the circuit breaker, and then through a line filter (US systems may not include the line filter). From the line filter the mains lines parallel out to two different areas.

Through F1/F2 and TB1 to the primary side of isolation transformer T1. TB1 allows tapping of isolation transformer T1 to match the incoming line voltage. The transformer has two secondary windings. One is the unswitched 24 VAC turn-on supply. The other is a switched 220 VAC supply to the fan, pump and DC supplies.

Through the main contactor to the high voltage power supply.

4.2.2 Circuit Breaker on, Keyswitch off

Refer to 8-2. When the circuit breaker is turned on, the AC mains voltage is applied to contacts 1 and 3 of the main contactor and across the primary of isolation transformer T1. Transformer T1 has two secondaries; a switched secondary and an unswitched secondary.

The unswitched secondary is the 24 VAC supply for the turn-on circuitry. The switched secondary is the 220 VAC supply to the fan, pump, DC power supply, and display power supply. Note that even with the keyswitch off, there are dangerous voltages present inside the unit.

With the keyswitch in the OFF position, the SW1-A OFF contact of the key switch is closed and the SW1-A START contact is open. The main contactor is de-energized and its contacts (L1, L2, L3) are open. K1 and K2 are de-energized.

4.2.3 Turn on

Refer to 8-2. To turn the unit on, the keyswitch is turned to the START position, then released to the ON position.

When the key switch is turned to the START position, it closes its SW1-A START contacts and opens its SW1A OFF contacts. 24 VAC is available from the unswitched secondary of the transformer to the control windings of K1 and the main contactor. Both energize.

When the main contactor energizes, its four sets of contacts close. Contacts L1 and L2 close to apply primary power to the high voltage power supply (HVPS). Contact L3 closes to apply the switched secondary current to the fan, pump, display power supply and low voltage power supply. SW4 closes to complete a portion of the "hold on" current loop to the control winding of the main contactor.

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Shortly after the pump begins running the water flow switch SW3 will close, allowing K2 to energize. Once K2 is energized the main contactor hold on loop is complete, and the main contactor will remain energized with the release of the keyswitch from the START position to the ON position. Note that if the keyswitch is released to the ON position before K2 energizes, the system will turn off.

The interlocked design of the turn-on circuitry prevents re-starting of the system without the user re-starting with the keyswitch.

4.2.4 Shutdown

Refer to 8-2. The system will turn off if any of the following occur.

Keyswitch moved to OFF position

Emergency Off button pressed

Turn off or trip of main circuit breaker

Blown F1 or F2 line fuse

Blown F3

Open T1 thermal switch

Front door opened (intermock switch)

Loss of coolant flow

Loss of facility power

4.2.5 Low Voltage Power Supplies

Refer to 8-3. A vendor supplied low voltage power supply provides +5 VDC, ±12 VDC, and +24 VDC for use throughout the system. It operates from the 220 VAC supply voltage from the secondary of T1. A 250V 5 amp fuse is mounted on the power supply. The 5 VDC and ±12 VDC lines are routed to the CPU PCB. The 24 VDC is routed to the CPU PCB and Shutter PCB. From the CPU PCB the 5 VDC supply is routed out to the touch screen display, remote control and Shutter PCB.

The vendor supplied HVPS includes a +15 VDC voltage output that is used on the HVPS side of the isolation circuits of the CPU PCB (U8, U9, U11, U99, U100, U48, U47, U41, U101, U13, U14).

CPU PCB U60 is a voltage regulator that develops a 5 VDC supply (5V ENCOD) for the Servo Motor PCB.

THEORY OF OPERATION 4-6

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4.3 COOLING

Refer to the Coolant System Simplified Diagram, figure 4.1. As the lamps in the laser head are flashed, heat energy is produced in the flash lamps, rods, and housings. The cooling system transfers the heat energy from the flash lamp, rod and housings to the outside air. It includes a de-ionized water coolant loop with a forced air heat exchanger. A speed controlled fan forces air through the heat exchanger. The cooling system also provides cooling for the two beam dumps.

The coolant is maintained nonconductive (de-ionized) to minimize corrosion in the cooling loop.

Coolant flow is monitored as a part of the 24 VAC loop to the main contactor. If flow is not sufficient the system will not start, and if already started it will shut off.

Coolant temperature is monitored by the control electronics. The software checks the coolant temperature at regular intervals, providing overtemperature disable (F52 and "OVERHEATING displayed at touch screen) when the coolant temperature reaches 35˚C. The disable clears when coolant temperature falls to 32˚C.

Coolant conductivity is monitored by the control electronics. The software checks the coolant conductivity at regular intervals, and will disable the system (F6) if the conductivity exceeds software limits. Note that the conductivity is effected by the action of the D/I filter. If the conductivity is excessive, running the system in its standby condition will allow water circulation through the D/I filter, eventually lowering the conductivity to an acceptable level. Conductivity will tend to be higher when the unit is first turned on, then decrease as the D/I filter removes charged particles. The D/I filter is a consumable item, and should be changed after about six months of use, or sooner if coolant conductivity problems occur.

The coolant pump operates continuously and at a constant speed from turn on to turn off. It circulates the coolant through the closed loop. A fan drives air over the heat exchanger. Fan speed is controlled by the Fan Speed Control PCB. The coolant pump must never be run dry.

The differential fan speed controller uses phase angle control of the AC line voltage to control the speed of the fan. The fan speed is controlled to minimize fan noise. The speed controller monitors air temperature into the fan and the coolant temperature at the point where it is hottest (where it exits the cavity module and is returned to the heat exchanger). As the coolant temperature rises above the ambient air temperature, the controller acts to increase the fan speed. The line voltage for the fan is supplied through a solid state relay on the PCB. When the relay is on, the line voltage is connected to the fan. When the relay is off, the line voltage is disconnected from the fan. Control circuitry on the PCB switches the relay on for only a portion of each AC cycle - as coolant temperature increases above air inlet temperature the relay is left on for a longer portion of the AC cycle, increasing the electrical power to the fan (the fan spins faster).

(Refer to 8-17) The DC voltage output of U4-8 sets the duty cycle for the SCR1 and SCR2 solid state relay circuit. U4-1 provides a negative voltage proportional to coolant temperature. U4-7 provides a positive voltage proportional to air inlet temperature. When coolant temperature and air inlet temperature are the same, the two voltages are equal in magnitude, and cancel each other out. The output of U4-14 and the setting of potentiometer R7 sets the minimum duty cycle. As coolant temperature increases, the output of U4-1 increases, and the control voltage out of U4-8 increases. The result is that the solid state relay remains on for a longer portion of the AC cycle, and the fan speed increases.

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4-7

FILL RES.

FLOW

SWITCH

D/I

FILTER

To turn on circuits

To CPU PCB coolant temperature sense circuit

LASER HEAD

WATER FILTER

PUMP

To CPU PCB coolant conductivity circuit

inlet

outlet

HEAT EXCHANGER

Coolant temp sensor

FAN

Fan Speed

inlet

RESERVOIR

Control PCB

Drain Hose

FIGURE 4.1 COOLANT SYSTEM SIMPLIFIED DIAGRAM

Air sensor

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4.4 CONTROL ELECTRONICS

4.4.1 Overview

The control electronics executes stored software instructions to safely operate the system in response to user inputs. For the purposes of this discussion the control electronics is divided into two major functional elements: the main processor (Mµp) and the safety processor (Sµp). Each processor runs its own set of software instructions. The instructions are different, but are written to run in conjunction with the other, i.e., each relies on actions by the other in order to operate. If either fails the other will be inhibited from continuing. The two processors communicate using a shared memory integrated circuit. Each reads and/or writes to specific areas of this shared memory to communicate with the other.

The main processor system provides overall control of system operation. It includes the following circuits/ functions.

Main Processor (Mµp) - Runs the main software program to provide overall control of system operation. Includes a 68000 microprocessor and its supporting circuits - ROM, RAM, programmable timer, digital I/O, interrupt handling, clock, and µp bus support circuits. Described in subtopic 4.4.2.

Shutter/Footswitch /Remote Interlock Circuit - Operates and monitors the position of the shutter; detects footswitch position; and monitors the remote Interlock connection. Described in subtopic

4.4.3.

Servo Motor Circuit - Positions the servo motor to point the servo imaging mirror to the selected Ho:YAG head. Described in subtopic 4.4.4.

HVPS & PFN Control Circuits - Provides charge level, lamp select, charge command, and triggering inputs to the HVPS and PFN circuits. Monitors status line inputs from the HVPS. Described in subtopic 4.4.5.

Energy Monitor Circuits - Provides three channels of Ho:YAG pulse energy monitoring. Described in subtopic 4.4.6.

Touch Screen and Remote Control Circuits - Provides user display and input functions. Described in subtopic 4.4.7

Aiming Diode Laser Circuit - Sets the aiming diode laser to its off, low, medium, or high intensity. Described in subtopic 4.4.8.

Fiber and Blast Shield Position Sense Circuits - Monitors the position of the fiber and blast shield. Described in subtopic 4.4.9.

Service Attenuator/Switch Monitor Circuits - Operates and monitors the position of the service attenuator. Monitors the condition of the service and diagnostic push-buttons located on the CPU PCB. Described in subtopic 4.4.10.

Coolant Temperature and Conductivity Monitoring Circuits - Monitors the coolant temperature and conductivity. Described in subtopic 4.4.11.

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Low Energy Attenuator Circuit - Operates and monitors the position of the low energy attenuator. Described in subtopic 4.4.12.

DC Power Supply Voltage Monitoring Circuits - Monitors the +5, +15 and -15 VDC supply voltages. Described in subtopic 4.4.13.

The safety processor provides independent monitoring of system operation and will disable system treatment delivery if an abnormal condition is detected. It includes a 68000 microprocessor and its supporting circuits (i.e., ROM, RAM, programmable timer, interrupt handling, clock, and µp bus support circuits) as well as an ADC, digital I/O and NOFIRE circuit. The safety processor is described in subtopic 4.4.14.

4.4.2 Main Processor

Refer to 8-4. Motorola MC68000 microprocessor U32 reads/writes to its memory and I/O devices over a 20 bit address bus and 16 bit data bus. Y1 provides an 8 MHz clock input to the microprocessor. The 8 MHz signal is also used as a clock input to the digital I/O chips (U43 and U44) and clock divider U33. The clock divider provides 1 MHz output to the programmable timer U45 and a 2 MHz output used by the servo controller U30.

At power up C61 begins charging through R89. After a short period the charge becomes sufficient to cause a low to high transition at U24 pin 1, releasing to a high the /HALT/ and /RESET/ lines into the microprocessor - the microprocessor begins executing the software instructions stored in EPROM's U52 and U53. Pressing Reset Switch SW2 provides the same reset when the system is already on.

U25 will drive the /RESET/ line low if the 5 VDC supply voltage falls below ≈ 3 VDC. The /RST/ signal is used to reset digital I/O chips U43 and U44, clock divider U33, and to set U65 to generate a delayed reset signal (/RSTD/) to servo controller U30.

U54 and U55 provide 4K of 16 bit nonvolatile read/write memory to the Mµp. Data stored in this NVRAM will be maintained even when power is removed.

U26 decodes the upper four bits of the address bus to enable the appropriate memory or memory mapped I/ O device. U56, U35, U34 U27, and U66 provide timing signals required to operate the address and data buses.

U46 encodes interrupt requests from the programmable timer, UART controller, and Sµp (NOFIRE signal) for input to the microprocessor. U51 provides interrupt acknowledge signals back to the I/O device requesting an interrupt when the microprocessor is ready to handle the interrupt.

U57 detects bus errors, forcing the microprocessor to trap to an error handling routine if a bus cycle does not complete within a set number of clocked "E" pulses.

Inputs from the vendor supplied DC power supply provide the Controller PCB with 5 VDC, 24 VDC, and ± 15 VDC through J5, as shown in the upper left corner of 8-5.

Programmable timer U45 (Refer to 8-5) provides timing functions for the main processor, including the following:

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1 MSEC TIMER - At 1 millisecond intervals an interrupt request is asserted by the timer. The main processor uses this interrupt to increment/decrement various registers used to time events, such as the Inactivity and Main Program Dead Timers.

INTEGRATE - The INTEGRATE signal controls the operation of the three energy monitor circuits. When this signal is low, the energy monitor circuits are activated to translate the energy measured by the pyrodetector into a voltage, and then to hold that voltage until the microprocessor reads it. When the INTEGRATE signal goes high the energy monitor circuits are turned off and reset to prepare them for measuring the next pulse. The timer is used to provide a precise starting point for enabling the energy monitor circuits approximately 100 µseconds after the fire pulse goes low.

Before a fire pulse, the INTEGRATE signal is high, and the TAI (timer A input) line is high. The / FIREPULSE/ signal is a very short low pulse that will cause the flip flop formed by U59- 6 and U59-3 to change states, driving the TAI line low. The TAI line high to low transition is the input that triggers the start of a timing cycle in the programmable timer TA channel. After the timed delay, the TA timer TAO output goes high, driving the INTEGRATE line low through U59-11 to enable the energy monitor circuits. After the main processor and safety processor have read the energy monitor circuits, the main processor resets the TA timer, setting the INTEGRATE line back to a high.

COMMUNICATION TIMING - The SI and SO lines may be used in the future to provide timing functions to an RS 232 port.

4.4.3 Shutter / Footswitch / Remote Interlock Circuits

The operation of the Shutter, Footswitch, and Remote Interlock circuits are related.

Remote Interlock refers to an external electrical jack that can be wired to a remote switch to disable the laser. If this loop is opened the laser is disabled and a BRH OPEN message appears on the touch screen. A dummy plug is supplied to directly connect across the loop if the customer does not wire to a remote switch. The jack is located on the system back panel.

The Footswitch is a foot operated SPDT switch and 12 foot cable. The user depresses the footswitch to fire the laser. The footswitch cable plugs into a jack on the back panel.

The Shutter is a solenoid operated mechanism that blocks the treatment beam path when the solenoid is energized, directing the beam into a water cooled beam dump. The shutter moves out of the beam path when the solenoid is energized. The main processor operates the shutter through one of its digital I/O ports. The safety processor can force the shutter closed with its /NOFIRE/ signal. The beam is blocked when the shutter solenoid is de-energized. Energizing the solenoid moves the shutter out of the beam path. The position of the shutter is monitored by two slotted optical switches. The switch outputs are monitored by the main processor digital I/O and by the safety processor.

Refer to the Shutter/Footswitch/Remote Interlock Circuits Simplified Diagram (Figure 4.2) and to the associated schematics in Section 8. The footswitch is connected to the 24 VDC ground through J12-2 on the Shutter PCB. When the footswitch is not depressed, the ground is applied to the N.C. return (J12-1) and the N.O. line is open. Note that the N.C. and N.O. lines are both sensed by the main processor and safety processor as digital I/O inputs, through opto-isolators. In this manner the processors can monitor the footswitch status.

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4-11

In addition to providing a sense input to the processors, the FOOT SW N.O. line completes the 24 VDC ground return path for the shutter solenoid. If the footswitch is not depressed, there is no complete path for current through the solenoid, so the shutter can not be removed from the beam path.

In a similar manner, the interlock loop is a part of the 24 VDC path to the shutter solenoid, connecting Shutter PCB J12 pin 4 to pin 5 when the BRH loop is closed. If the loop opens, the 24 VDC path for the shutter solenoid is opened and the shutter can not be removed from the beam path. The BRH SNC line is sensed as a digital I/O input to the main processor, allowing the processor to detect an open BRH loop.

SHUTTER LPT3 LPT2 SHTRNO /SHTRNC/ closed on off high low opened off on low high

P/O Dual Solenoid PCB

SHTR SNC NO

LPT3

LPT2

P/O Shutter PCB

5 VDC

SHTR SNC NC

24 VDC

P/O CPU PCB

SHTR DR SNC

FOOT SW N.O.

FOOT SW N.C.

BRH SNC

MCT6

/FTSWNC/

FTSWNO

/NO FIRE/

SHTRNO

/SHTRNC/

SHTRNO

SHTRDRSN

SHTR DR

FTSWNO

/FTSWNC/

/BRHOK/

SµP DIO

MµP DIO

FOOTSWITCH FTSWNO /FTSWNC/ released high low depressed low high

FIGURE 4.2 SHUTTER, FOOTSWITCH, REMOTE INTERLOCK SIMPLIFIED DIAGRAM

THEORY OF OPERATION 4-12

REMOTE

INTERLOCK

FTSW (shown depressed)

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Assuming that the interlock loop is complete and the footswitch is depressed, the shutter will be opened when the main processor asserts its digital I/O output SHTR DR to turn on Q2. Note that the SHTR DR signal is gated on the CPU PCB by the safety processor /NOFIRE/ signal (AND gate U64-6). The safety processor can prevent the shutter from opening by asserting /NOFIRE/ (low). The SHTR DR SNC line is a main processor digital I/O input, allowing the processor to sense the presence or absence of the 24 VDC through Q2 when the footswitch is not depressed.

Q1 operates momentarily each time Q2 turns on to bypass the shutter solenoid current around resistor R3 as the shutter is moved into place, then turns off to drop the shutter solenoid current to a lower "holding" level.

Shutter position is monitored by LPT2 and LPT3 on the Dual Solenoid PCB. The two are complementary - for the two shutter positions (opened or closed) one switch is blocked and the other is unblocked. Both devices are supplied with 5 VDC and return ground from the Dual Solenoid PCB.

Sensed signals and drive signals are isolated through opto-isolators where the signals leave or enter the CPU PCB.

4.4.4 Servo Motor Control Circuit

A moving mirror is used to multiplex the (up to) four Ho:YAG head outputs into a single beam path. A servo motor is used to precisely position this imaging mirror to any one of the four possible YAG head outputs. The mirror is mounted to the end of the motor shaft, at a slight angle, so that as the shaft rotates through 360˚, the mirror orientation changes. Between YAG pulses the mirror must be moved to and stopped at the point in its rotation that aligns it with the output coupler of the head that will be fired next. After the pulse, it must be moved to the next head to be fired, and so on for as long as firing continues.

24 VDC P/S

P/O CPU PCB

/RSTD/ 2MHZ

MAIN

PROCESSOR

MAIN

PROCESSOR

DIGITAL

I/O

MAIN PROCESSOR

DATA BUS

/SCALE/

/SCOE/ /SCCS/

R/W

MOTOR

CONTROLLER

CHANNEL A

CHANNEL B

/SRVINDEX/

DIRECTION

PULSE

POSITION

SENSE

Servo Amp PCB

MOTOR SUPPLY

MOTOR

MIRROR

FIGURE 4.3 SERVO MOTOR CONTROL CIRCUIT SIMPLIFIED DIAGRAM

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24 VDC

U60

5V ENCODE

THEORY OF OPERATION

4-13

Refer to the Servo Motor Control Circuit Simplified Diagram (figure 4.3) and to the associated schematics in Section 8. Motor controller U30 receives position commands from the main processor over the microprocessor bus. It outputs direction and pulse commands to Servo Amp PCB motor supply U1. The motor supply provides switched DC to the motor, in the polarity indicated by the direction input from the motor controller, and in time increments as indicated by the pulse input. Note that in the Versapulse Select the motor always moves in the same direction, but the reverse direction signal is still used to providing braking force as the motor approaches a new stop position.

Motor movement information is fed back to the motor controller from an optical sensor located behind the motor. The channel A and B feedback lines each provide 2000 counts per revolution, and are offset from each other to provide a total of 4000 counts for one rotation. The position sensor also detects a specific position, referred to as the index position. The index position information is reported to the main processor through a digital I/O input port as /SRVINDX/. Once the index position is found, the motor controller tracks position by monitoring the channel A and B lines from the position sensor to determine the sum of the movement away from this known index position.

4.4.5 HVPS & PFN Control Circuits

The HVPS and PFN control circuits oversee the charging and discharging of the main charging capacitor, monitor the charge on the capacitor, and monitor several status signals from the high voltage power supply.

Refer to the HVPS & PFN Interface Circuits Simplified Diagram (Figure 4.4) and to the related schematics in Section 8. The main charging capacitor is charged by the vendor supplied high voltage power supply, referred to as the HVPS. The control circuit on the CPU PCB sends the HVPS a charge enable (RS ENABLE) signal and charge level information (HVPS DR VOLTS). The HVPS sends fault status (TEMP OL, CURRENT OL, NO CURRENT REVERSAL ), charge level (CAP FD BK), and charge complete (CHARGE) signals to the control circuit.

To discharge the capacitor through a particular flash lamp, the control circuit on the CPU PCB routes a fire pulse (/FIREPLS/) to one of the four trigger circuits on the Isolated Trigger PCB. When the fire pulse is asserted, the selected trigger circuit will gate on an SCR to create a complete path for capacitor discharge through the selected lamp.

CHARGING PROCESS - The main processor first calculates the level of charge required to provide the selected pulse energy at the selected pulse rate. The selected energy and pulse rate index a capacitor charge value in the stored calibration data. The data is established during automatic laser calibration and updated by light feedback information from any previous pulses at the selected operating point.

The first pulse of a treatment delivery (i.e., the first pulse after the footswitch is depressed) includes a correction factor to compensate for differences in cavity output that occur before the thermal lens has formed. Subsequent pulses do not require this correction factor.

Once the main processor has determined the level of charge required, it writes the digital value for the required voltage to DAC U10. The DAC output, HVDAC, is 0 to 5 VDC for a main capacitor charging voltage of 700 volts to 1400 volts. The HVDAC signal is sent through amplifier U15, analog opto-isolator U14, and amplifier U101 to become HVPS DR VOLTS, out on J2-18 of the CPU PCB to the HVPS module. Note that the HVDAC signal is also input to both the main processor and safety processor ADC circuits.

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(HVDAC is 0 -5 VDC for 700 to 1500 Volts of requested cap charge for Ho only, 200 - 1500 Volts for dual wavelength)

SµP

ADC

Mµp

SµP

SµP DIO

DAC

DIO

HVDAC

/FIREPLS/

/NOFIRE/

ADC

U14/15/101

FIRE SELECT LINES

TRG I

TRG II

TRG III

TRG IV

OPTO

ISO

XMTR'S

HVPS DRIVE

TP11 (CAP VOLTS, 5 to 10 VDC for 700 -1500 VOLT cap charge)

CAP FD BK

Isolated Trigger PCB

30 V

ZENER

TRG I

TRG II

TRG III

TRG IV

RCVR'S

OPTICAL FIBER

CONNECTIONS

TEMP OL

NO CAP CURRENT OL RS ENABLE

CHARGE

HVPS

SCR'S

400 VDC Simmer Supply Voltage

MAIN CHARGING

CAPACITOR

SIMMER

P/S

P/O CPU PCB

I II III

FLASHLAMPS

FIGURE 4.4 HVPS & PFN CONTROL CIRCUITS SIMPLIFIED DIAGRAM

With the charge level information calculated and available on the HVDAC line, the main processor asserts its digital I/O signal HVPSENBL (U43 pin 6). The HVPS signal is applied to U64 pin 9 and as the B input to monostable multivibrator U65. U65 is triggered to its set state for a 50 msec period each time the B input goes high (more than enough time to charge the capacitor). The multivibrator insures that in no case can an enable to the HVPS last longer than 50 milliseconds. This prevents damage to the supply if the HVPSENBL signal should hang up in the high state. The Q output of U65 is the other input to AND gate U64-8. The output of U64 -8 (HVENTM) is anded with the /NOFIRE/ signal at AND gate U64-3. The /NOFIRE/ signal is set low by the safety processor to disable the HVPS when it detects a problem with system operation. Otherwise / NOFIRE/ is high, and the output of U64-3 follows the HVENTM signal. The output of U64-3 is sent through inverter U40-6 to drive opto-isolator U100, and on to the HVPS as RS ENABLE. When this signal is asserted, the HVPS begins charging to the level indicated by the HVDAC signal.

The HVPS provides a CAP FD BK signal to the CPU through U101, U13 and U15. The signal is 5 to 10 VDC for a cap charge level of 700 to 1500 Volts. Both the main and safety processor ADC circuits read this voltage.

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THEORY OF OPERATION

4-15

FIRING A LAMP - Firing consists of selecting the appropriate lamp for discharge, then providing a trigger to cause the discharge at the appropriate time to provide the selected pulse interval.

Each flash lamp has a triggering SCR in series with it. The four sets of flash lamps and SCR's are connected in parallel (as shown in the block diagram). Each SCR gate is connected to a trigger circuit (located on the Trigger PCB). When triggered, the trigger circuit gates its associated SCR on, establishing a current path for discharge of the main charging cap through the associated lamp.

Prior to firing, the main processor determines which head is to be fired next and connects the /FIREPLS/ signal to the appropriate trigger circuit. The selection is made by the U43 digital I/O outputs LASLCTA, LASLCTB, LASLTC. These three lines provide a binary coded input to decoder/multiplexer U42. U42 decodes the select inputs to determine which of its four connected outputs (Y1, Y2, Y3, Y4) to connect with the /FIREPLS/ input. The four output lines are the trigger inputs to the four trigger circuits. The main processor uses U42 to route the /FIREPLS/ signal to the appropriate trigger circuit.

Each trigger line out of U42 is attached to an infrared transmitter (XTRM1 through 4). Optical fibers carry the signal from the XTRM's to infrared receivers (RECV 1 through 4) on the Isolated Trigger PCB.

The pulse interval is the period of time that falls between the pulses during firing. For example, a 20 Hz pulse rate has a pulse interval 50 milliseconds, i.e., the /FIREPLS/ signal should occur every 50 milliseconds. The /FIREPLS/ interval is monitored by both the main and safety processors.

The main processor asserts /FIREPLS/ low out of Digital I/O chip U43 (pin 33) to fire the selected head. Assume head 1 is to be fired. The /FIREPLS/ signal is routed through the decoder (U42) out on pin 14 to pin 1 of amplifier U50 and then on to XTRM1 (turns on). At the Isolated Trigger PCB, the infrared signal turns on RECV1, to turn on gate Q1. Q1 on connects the SCR1 gate to 30 VDC through R2. This triggers the SCR, providing a discharge path for the main charging capacitor through Flash Lamp 1.

MONITORED SIGNALS - The HVPS provides several digital status signals back to the control circuit as well as an analog capacitor charge feedback signal.

TEMP OL - The HVPS grounds this line to indicate an overtemperature condition has been detected at the HVPS. It enters the CPU PCB at J2-6 and goes through opto-isolator U8 to become /HVPTOL/ (low when the fault condition exists), input to digital I/O U44 pin 22.

CURRENT OL - The HVPS grounds this line when the HVPS is operated at too high a duty cycle. It enters the Controller at J2-10 and goes through opto-isolator U8 to become /HVPCOL/ (low when the fault condition exists), input to digital I/O U44 pin 23.

NO CAP - The HVPS grounds this line when the HVPS detects a problem on the output line to the charging capacitor. It enters the CPU PCB at J2-12 and goes through opto-isolator U11 /HVPNCR/ (low when the fault condition exists), input to digital I/O U44 pin 24.

CHARGE - The HVPS grounds this line when the main charging capacitor has been charged to the requested level. It enters the CPU PCB at J2-9 and goes through opto-isolator U99 to become / HVPCRI/, input to digital I/O U44 pin 21.

THEORY OF OPERATION 4-16

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4.4.6 Energy Monitor Circuits

Refer to the Energy Monitor Circuits Simplified Diagram (Figure 4.5) and to the associated schematics in Section 8. The VersaPulse Select measures the energy of each YAG pulse. Three separate channels measure the energy. Two channels are required to provide safety redundancy; the third is provided to check the pulse energy downstream from the low energy attenuator.

• ENERGY I - Monitors ENERGY I circuitry (redundancy).

• ENERGY II - Laser energy feedback loop signal.

• ENERGY III - Monitors energy delivered to fiber (after low energy attenuator).

The measurement is accomplished by directing a small percentage of the pulse to strike a pyrodetector. The detector outputs a current the integral of which is proportional to the energy in the pulse. The current signal is converted to a voltage, integrated, and then the result of the integration is held for reading by the processor ADC circuits (both main and safety processors read the energy monitor circuit outputs after each pulse). After the energy monitor outputs are read the circuits are reset and disabled until the next pulse. Each circuit is calibrated by adjusting a potentiometer.

The remainder of this subtopic describes the ENERGY I circuitry and optics. The ENERGY II and ENERGY III circuits operate in the same manner.

P/O Single Sol. PCB

PYRO I

PYRO II

P/O Dual Sol. PCB

PYRO III

Transimpedence

ENERGY I

ENERGY II

ENERGY III

Integration

Peak Holding

TP1

TP2

TP3

TP4

SµP ADC

MµP ADC

MµP TIMER

Shutter PCB

P/O CPU PCB

FIGURE 4.5 ENERGY MONITOR CIRCUITS SIMPLIFIED DIAGRAM

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INTEGRATE

THEORY OF OPERATION

4-17

A small sample (≈0.2%) of each YAG pulse is deflected from the first surface of the first (synthetic) sapphire wedge optic to an imaging mirror. The imaging mirror forms an image of the rod end on the ENERGY I pyrodetector (located on the Single Solenoid PCB). The heat generated by this energy striking the pyrodetector generates a small current, the integral of which is proportional to the energy in the pulse. Transimpedence amplifier U1-1 converts the current to a voltage which is integrated by U1-7. U16-7 acts as a peak hold circuit, charging C9 to the highest level seen out of the integrator (U1-7) for a given pulse. At this point the ENERGY I signal is ready to be measured by the main and safety processors through the ADC.

The imaging mirror is used to provide a constant image size on the pyrodetector surface for different beam sizes (the beam cross section trends smaller as pump energy increases). This provides a more consistent energy sampling across the range of pulse energy.

After the value of the ENERGY I line is read the ENERGY I circuit must be reset before the next pulse is delivered. To reset the circuit the main processor asserts the INTEGRATE line (high) to close U5 contacts 3 to 2 and 6 to 7. Contacts 3 to 2 closed resets the integrator. Contacts 6 to 7 closed discharges C9 to reset the peak hold circuit.

R7,R8 & R9 are adjusted during servicing to calibrate the energy monitor circuit.

4.4.7 Touch Screen & Remote Control Circuits

The touch screen display and optional wired remote control module display information to, and receive operator inputs from, the user. The touch screen is the primary user interface. The optional wired remote control provides most operator displays and functions in a package that can be bagged and taken inside the sterile field.

The touch screen display is an AC plasma display with an overlaid infrared matrix.

The remote control includes a dot matrix display and 7 push-buttons.

Refer to the Touch Screen Display & Remote Control Simplifed Diagram (Figure 4.6) and to the associated schematics in Section 8. To update the touch screen display, the main processor writes the screen information to the dual channel UART controller. The UART then transmits the data in serial form out on the TXA line to differential Driver U95. U95 translates the single line input into a differential signal out on pins 2 and 3 to the touch screen display. This screen information provides parameter and status indications and marks off areas of the screen for user inputs.

At the touch screen, operator input is detected as an interruption of a matrix of vertical and horizontal infrared beams transmitted and detected just above the surface of the display screen. The LEDs are arranged in two rows; one row along the bottom of the screen and one row along the right side of the screen. Infrared detectors are located along the two opposite sides (left and top) of the display. Each LED output is directed across the screen to the input of its associated detector. When the user touches the screen, some of the horizontal and vertical infrared beams above it are interrupted, and this information is transmitted through the differential bus receiver to both the safety processor and main processor UARTs (RXA line), and then on to the respective processors.

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Both the main and safety processors decode the user input information to determine if the horizontal and vertical information indicates that the user has pressed an area of the screen that represents a valid user input. In user mode, the main processor does not respond directly to user inputs: instead, the main processor responds to messages from the safety processor through the shared memory indicating an input has occurred. In service mode the main processor responds directly to control panel inputs.

The remote control communicates with the main and safety processor in the same way, over the B channels of the main and safety processor UARTs.

The RS232 port is provided for use in automated testing, and is not used in normal operation.

A beeper (not shown on simplified schematic) is attached to the main processor programmable timer through audio amplifier U38. The beeper is mounted inside the touch screen display. The main processor writes to the timer to drive the beeper. The beeper is used in this manner to draw the user's attention to various conditions (e.g., input accepted, input rejected, fault, etc). Beeper volume is adjusted by R98.

FIGURE 4.6 TOUCH SCREEN AND REMOTE CONTROL SIMPLIFIED DIAGRAM

TOUCH SCREEN

WIRED REMOTE

P/O CPU PCB

SµP

CHANNEL A

DIFFERENTIAL BUS

DRIVER (p/o U95) & RECEIVER (p/o U96)

CHANNEL B

DIFFERENTIAL BUS

DRIVER (p/o U95) & RECEIVER (p/o U96)

To Programmable Timer U45

RS232 BUS, not used during normal operations.

DUAL UART

CONTROLLER

RXA

TXA

RXB

TXB

MµP

SµP

DUAL UART

CONTROLLER

MµP

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4.4.8 Aiming Diode Laser Circuit

The aiming diode laser module is mounted on the optics plate, just prior to the fiber focus assembly, and after the safety shutter (the safety shutter can not block the diode aiming beam). The diode output is directed by a folding mirror to a beam combiner. Both the folding mirror and beam combiner are adjustable, providing a near and far adjustment to place the aiming beam coaxial to the treatment beam.

Refer to the Aiming Diode Laser Simplified Diagram (figure 4.6) and to the associated schematics in Section 8. The aiming laser is supplied with 5 VDC through J15-5 on the Shutter PCB. The return line for the 5 VDC supply is switched through Shutter PCB Q6. Q6 is turned on or off by the AIMON signal from the CPU PCB (main processor digital I/O) to turn the aiming beam on or off.

Aiming beam intensity is controlled by variable resistance U49 on the CPU PCB connected to the aiming beam module through the Shutter PCB (J15-2). The main processor sets the aiming beam intensity to high, low, or medium by changing the variable resistance (U49) using the /AIMINC/ and /AIMU-D/ digital I/O output lines.

Folding (near) Mirror

Beam Combiner

Laser Diode

YAG BEAM PATH

P/O Shutter PCB

5 VDC

P/O CPU PCB

Variable

Resistance

U49

/AIMINC/

/AIMU/D/

AIMON

MµP DIO

FIGURE 4.6 AIMING DIODE LASER CIRCUIT SIMPLIFIED DIAGRAM

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4.4.9 Fiber and Blast Shield Position Sense Circuits

Refer to the Fiber and Blast Shield Position Sense Simplified Diagram (figure 4.7) and to the associated schematics in Section 8. The Versapulse Selectwill not allow treatment delivery if it senses that the blast shield is not inserted or that a fiber is not properly attached.

The blast shield position is sensed by a microswitch that closes when the blast shield is properly inserted. A ground from the Shutter PCB is applied through the microswitch, back through the Shutter PCB and on to the main processor digital I/O through U98-2 on the CPU PCB (BLST SHLD). The BLST SHLD signal is high when the blast shield is properly inserted.

Correct fiber attachment is important to insure proper Z position of the focusing lens in relation to the end of the fiber. As the fiber is screwed onto the SMA connector, it forces a spring loaded cover plate inwards towards the fiber focus assembly. Whenthe fiber is completely screwed down it provides two separate electrical indications:

The cover plate activates a microswitch, causing the switch to open. The switch open removes ground from the FIBER SW N.C.. The FIBER SW N.C. line goes through the Shutter PCB to the CPU PCB ((J1-

15) where it is inverted to become the /FBRSNC/ signal, a main processor digital I/O input.

The cover plate physically contacts the SMA connector and fiber focus assembly housing, completing an electrical connection to ground for the FIBER NO line. The FIBER NO line is inverted to become / FBRSNO/, a main processor digital I/O input.

Fiber Focus

Assembly

P/O Shutter PCB

FIBER

COVER PLATE

P/O CPU PCB

BLAST SHIELD

FIGURE 4.7 FIBER & BLAST SHIELD POSITION SENSE SIMPLIFED DIAGRAM

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FBR SW N.C.

FBR SW N.O.

BLST SHLD

MµP DIO

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4.4.10 Service Attenuator Circuit

The service attenuator is inserted into the beam path during servicing to prevent damage to the end of an attached fiber (and blast shield). It is used when the alignment of the YAG beam is not known to be good into the end of the fiber. The attenuator provides greater than 99% attenuation. A service switch located on the Shutter PCB is activated by the servicing engineer in order to operate the service attenuator. The switch turns the service solenoid on, placing the attenuator in the beam path. Position is sensed by a slotted optical switch.

Refer to the Service Attenuator Simplified Diagram below and to the associated schematics in Section 8. Closing switch SW1 on the Shutter PCB provides the ground return path for the 24 VDC supply to the solenoid. The solenoid energizes to move the attenuator into the beam path. The attenuator position is monitored by slotted optical switch LPT1. The SER SNC N.O. line is opened when the switch is blocked and grounded when the switch is not blocked. The signal is sent through the Shutter PCB to the main processor digital I/O on the Controller PCB (signal SER ATN NO).

P/O Dual Solenoid PCB

P/O Shutter PCB

24 VDC

SER ATEN NO

SW1

5 VDC

SER SNC N.O.

5 VDC

In the beam path when energized.

P/O CPU PCB

/SERATNO/

MµP DIO

FIGURE 4.8 SERVICE ATTENUATOR SIMPLIFIED DIAGRAM

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4.4.11 Coolant Temperature and Conductivity Monitoring Circuits

Coolant temperature and conductivity are monitored by sensors that report an analog voltage to the main processor ADC circuit. Refer to the Coolant Temperature and Conductivity Monitor Simplified Diagram below and to the associated schematics in Section 8.

P/O CPU PCB

WATER FILTER

COOLANT RES.

10 V Ref

R36

U17

-15 VDC

DEMOD

U17-14 U17-8

70 Hz OSC

Conductivity in µSeimans = .25(Voltage @ TP10)

TP9

(coolant temp)

MµP ADC

(conductivity)

TP10

Temp in C = 10(Voltage @ TP9)

FIGURE 4.9 COOLANT TEMP & CONDUCTIVITY MONITORING SIMPLIFIED DIAGRAM

TEMPERATURE - The temperature is monitored by a current source suspended in the coolant. Its current

output changes linearly with changes in coolant temperature. The current source is supplied with -15 VDC from J4-5. The output of U17 (pin 1, also TP9) is:

.1 VDC/degree C (e.g., 3 Volts at TP9 indicates a sensed temperature of 30˚C)

R36 is an offset adjustment. U12-1 isolates the 10 VDC reference voltage from ADC U20.

CONDUCTIVITY - The coolant (distilled or de-ionized water) is maintained nonconductive to minimize corrosion. A de-ionizing filter (DI filter) is included in the coolant loop to removed charged particles from the coolant. The filter is a consumable item - it requires periodic replacement.

The main processor monitors the coolant conductivity to insure that it remains within an acceptable range, and to confirm that the DI filter is operating properly.

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At turn on the coolant conductivity will tend to be higher, especially if the system has not been operated recently, and then will decrease as the system coolant begins to circulate through the DI filter. Note that the system software takes into account that the conductivity will be higher just after turn on, and then, if the DI filter is operating properly, the conductivity will gradually drop.

The 70 Hz output of U17 leaves the CPU PCB at J4-2 and is routed to the coolant reservoir where the signal is applied across a one cm gap in the coolant. The other side of the one cm gap is sensed at J4-1 (CONDUCTIVITY SIGNAL), and input to transimpedence amplifier U17-14 . The output of U17-14 consists of positive and negative pulses. The individual pulses are selected for input to the positive and negative inputs of U17-9 by the action of U18-10 and U18-15 as driven by the oscillator U17-7 outputs (partly through U18-6). The output of U17-8 (TP10) is 4 times the sensed conductivity in µS Siemens (e.g., a voltage of 3.5 volts at TP10 indicates a sensed conductivity of 15 µS).

4.4.12 Low Energy Attenuator Circuit

The Low energy attenuator circuit inserts attenuation into the beam path to allow the Versapulse Select to provide treatment pulse energies lower than the minimum pulse energy available out of the cavity.

The main processor asserts (high) the LPATTNDR signal to insert the attenuator. LPATTNDR is applied through amplifier U40 (3/4) to opto-isolator U41. The U41 pin 8 output (24 VDC to insert) is connected to Shutter PCB J11 -10, where it is applied to the base of Q4. Q4 on completes the ground return path for the 24 VDC supply to the solenoid that inserts the low power attenuator. The Low energy Solenoid is located on the Single Solenoid PCB.

The Low Power Attenuator "normally open" signal (LPATNO) is the output of slotted optical switch LPT1 on the Single Solenoid PCB.

When the switch is blocked, its sensed output is open. When the switch is not blocked its output is a ground. The switch is blocked when the attenuator is energized, blocking the beam. The sensed line from LPT1 is sent from the Single Solenoid PCB to the Shutter PCB, J17-11 to J14-11, then on to the Controller PCB, J11-11 to CPU PCB J1-11. When the solenoid is energized, the service attenuator is in the beam path, LPT1 output is open/ground, and Controller PCB U39-8 is forced high/low.

4.4.13 DC Power Supply Voltage Monitoring Circuits

Refer to 8-6. The main processor monitors the ±15 and +5 VDC power supply outputs through its ADC circuit. The ± 15 VDC inputs are too large to be directly measured through the ADC, so both are divided down to a lower level before input to the ADC MUX (U19). The -15 VDC is measured through voltage divider R40/41 and inverting amplifier (gain is 1) as -15M (TP8). The +15 VDC is measured through voltage divider RR38/39 as +15M. The +5 VDC is monitored directly, through R37 as +5M.

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4.4.14 Safety Processor

The safety processor provides monitoring of system operation independent of the main processor. Refer to 8-

8. Microprocessor U80 is the safety microprocessor. Its software instructions are stored in EPROM's U88 and U89. U90 and U91 provide 4K of 16 bit nonvolatile memory. Y3 provides an 8 MHZ system clock. U81 detects bus errors on the address bus, forcing the processor to trap if a bus cycle does not complete. U87 and U86 process interrupt request and acknowledge signals. U73, U75, U83 and U84 provide various address and data bus signals.

U79 provides 256 bytes of dual channel read/write memory. The main processor and safety processor can both read or write to this shared memory resource. The memory is essentially a communication link between the two processors. Both write information in specified areas of this memory which the other can read to determine status of the other processor.

For example, before firing one of the YAG heads, the main processor writes to the shared memory indicating which laser head it is about to fire. The safety processor reads this information, and if it is the same YAG head that the safety processor expects to be fired, it writes that same information back into the shared memory. The main processor then reads the information written into the shared memory by the safety processor, checks it against the original information of the head it was preparing to fire, and, if all checks have agreed, the firing sequence continues. Numerous such cross checks occur in the software. The two sets of software are written to work together, and to confirm with each other through this shared memory resource all aspects of safe operation.

Dual UART U85 provides two channels of receive asynchronous communication for the safety processor. The safety processor uses its RXDA and RXDB receive lines to monitor the asynchronous communication transmissions from the touch screen display and remote control. In this manner it can determine operator inputs. The main processor and safety processor use the shared memory to confirm agreement of all received operator inputs over these lines. Note that the safety processor dual UART transmit lines are not connected - the safety processor does not transmit information over the asynchronous bus.

U78 provides the safety processor digital I/O and programmable timer functions.

Its "A" channel lines are used to monitor 7 digital inputs and to provide the /NOFIRE/ output. It monitors the normally open and normally closed signals from both the footswitch and shutter (SHTRNO, /SHTRNC/, FTSWNO, /FTSWNC/), the service switch, and the INTEGRATE signal (generated by the main processor programmable timer).

Whenever the safety processor software detects a potential problem with system operation, it can assert its digital I/O /NOFIRE/ signal low. This signal will inhibit the laser from firing by:

Forcing the output of U64-3 low. This is the RS ENABLE to the HVPS. A low on this line disables the HVPS from charging the main charging capacitor.

Forcing the output of U64-6 low. This is the SHUTTER DRIVE signal going to the Shutter PCB to switch on or off the shutter solenoid. A low turns off the FET switch on the Shutter PCB, opening the current path for the shutter solenoid. This forces the shutter solenoid into its de-energized position, blocking the treatment beam path.

Gating off U42. U42 is the multiplexer that connects the /FIREPLS/ signal with one of the four trigger outputs. /NOFIRE/ low opens all four of the outputs, preventing a trigger from being generated.

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Reporting the "nofire" condition to the main processor through the main processor digital I/ O at U44 pin 20.

U78 "B" channel operates the three SMUX lines that select the input to the safety processor ADC circuit at multiplexer U78.

U78 channel "C" provides timing functions for the safety processor, including the 1 msec interrupt.

The safety processor writes to its digital I/O to set the SMUX0, SMUX1, and SMUX2 lines. These three lines are the select inputs to multiplexer U76. Based on its select inputs, the multiplexer will select one of the four analog voltages on its input lines for output to analog to digital convertor U68. U68 converts the DC voltage input to a digital value and stores it in registers U69 and U70. The safety processor can then read in the digital value representing the analog voltage.

The ADC circuit can read the analog outputs from the energy monitor circuits and the HVDAC voltage.

U93, DIS I and DIS II are used to provide a 2 digit seven segment display for the safety processor. The display is used in system testing/de-bugging.

P/O CPU PCB

SµP DIO

SµP

/NOFIRE/

When the /NOFIRE signal is aserted low:

1. Opens the four trigger outputs from U42.

2. Forces U64-3 low, disabling the HVPS from charging the main charging capacitor.

3. Forces the U64-6 low, disabling drive to the shutter solenoid.

4.) DIO input to main processor.

MµP DIO

FIREPLS

HVENTM

SHTRDR

MµP

U42

TRIG 1

TRIG 2 TRIG 3

TRIG 4

U64-3

U64-6

MCT6

TO ISOLATED TRIGGER PCB

RS ENABLE

SHTR. DR

FIGURE 4.10 SAFETY PROCESSOR NOFIRE CIRCUIT SIMPLIFIED DIAGRAM

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4.5 FLASH LAMP POWER CIRCUITS

Refer to the Isolated Trigger Board PCB schematic in Section 8, and the HVPS & PFN Interface Circuits Simplified Block Diagram in topic 4.4.5. The flash lamp power circuits include the HVPS, simmer supply, isolated trigger circuits, main charging capacitor circuit, flash lamp SCR's and the flash lamps. These circuits operate together to start and simmer the flash lamps between firings; charge the PFN capacitor before firing; and then trigger the discharge of the main charging capacitor through the selected flash lamp.

Simmer - The flash lamps are simmered at a low current between pulses simply to maintain the electrical path to the SCR anode side - i.e., if the lamp was not conducting (open circuit on lamp cathode side) the SCR could not be gated on. The lamp is simmering but the rod is not simmering. The simmer board provides a separate simmer supply current for each flash lamp, as well as suppling a transformer coupled RF field around each flash lamp to promote ionizing of the flash lamp at turn on. The RF field is established by connecting a transformer secondary to the cavity housing, which is electrically isolated from the chassis. The Simmer board operates off of 400 VDC supplied by the HVPS. C7, R11 and DS2 provide an indication of the presence of the 400 VDC supply voltage to the simmer supply board.

Charging the PFN Capacitor - Prior to each YAG pulse the HVPS charges the PFN cap to the level specified by the Cap charge command voltage signal from the Controller PCB. The range of charge is from 700 to 1400 VDC. The level of charge determines the pulse energy. R1, C1 and DS1 form a charge level indicator. DS1 flashes faster as the level of charge on the capacitor increases.

Discharging the PFN capacitor - There are four identical isolated trigger circuits on the Isolated Trigger PCB

- one for each of the four flash lamp circuits. Each has an optical fiber input from the controller PCB, and an output to its associated flash lamp SCR. All four circuits share a common 30 VDC supply developed by zener CR1 from the main charging capacitor voltage. All four circuits are functionally the same - the Trigger I circuit operation will be described in the next paragraph.

To discharge the PFN capacitor through the I flash lamp, the Controller PCB sends a pulse of infrared light through the optical fiber connected to RECV 1. RECV turns on, turning on its associated FET Q1. Q1 on connects the 30 VDC through R2 to the gate of an SCR connected between capacitor ground and the cathode of the flash lamp. The SCR turns on, providing a discharge path for current from the main charging capacitor through the flash lamp and SCR to capacitor ground.

4.6 OPTICS

The optics include all components that act on the aiming and/or treatment beam. This includes the Ho:YAG cavity module; Ho:YAG combining optics; folding mirrors; the energy sample optics; shutters; attenuators; aiming beam laser and combining optics; the fiber focusing lens and blast shield.

Ho:YAG CAVITY - The Ho:YAG cavity provides pulsed output of 2.1 micron wavelength light energy. The cavity is pumped with a xenon flash lamp. The lasing medium is a Ho:YAG rod. The rod is positioned between an HR and OC (≈ 15% leakage) mirror. Up to four such cavities can be housed in a single Versapulse Select system.

MULTIPLEXING OPTICS - The multiplexing optics consist of an imaging and flat mirror for each cavity, and the servo positioned imaging mirror. For each cavity, an imaging mirror directs the OC output off a flat mirror to the surface of the servo positioned imaging mirror. The servo positioned mirror can be rotated to line up with each of the up to four YAG beam paths, so that each output is directed down a common beam path.

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PRIMARY BEAM PATH - the servo positioned mirror output is directed through two folding mirrors towards the fiber focusing lens. In its path are the following additional optical components.

First Wedge Optic - The wedge optic front and back surfaces each reflect a small portion (≈

0.2%) of the YAG energy back towards an imaging mirror. The imaging mirror is positioned to direct these reflections upon two pyrodetectors mounted on the Single Solenoid PCB, one sample to each pyro. The pyro circuitry translates the energy sample into a voltage proportional to the energy of the Ho:YAG pulse. To maximize the accuracy of the energy sampling the wedge optic uses a simple coating and a near normal pick off angle. The imaging mirror maintains a constant image size on the pyrodetector surface over the range of beam diameters (the beam diameter decreases at higher pulse energies).

Low Power Attenuator - The LP attenuator can be inserted into the beam path to decrease the treatment beam power. This allows the system to deliver pulse energies lower than the lowest stable pulse energy available out of the YAG head. Currently the low power attenuator feature is not implemented by the software.

Second Wedge Optic - A second wedge optic is required to check the power after the low power attenuator. Although two samples are reflected off the wedge, only one is used. An imaging mirror directs the sample towards a pyrodetector mounted on the Dual Solenoid PCB. The pyro circuitry translates the energy sample into a voltage proportional to the energy of the Ho:YAG pulse.

Service Attenuator - The service attenuator is inserted into the beam path to attenuate the treatment beam before it is focused into the end of the fiber. It is operated by a switch inside the unit accessible to the servicing technician. The attenuation is used during alignment procedures. The system will not operate in user mode if the service attenuator is in the beam path.

Safety Shutter - Blocks the treatment beam path when de-energized.

Aiming Beam Diode and Combiner Optic - A red (650 nm) aiming beam is provided by a

diode laser mounted in the optical head. The user can turn the aiming beam of or select high, low, or medium intensity. The diode output is directed by a folding mirror to a beam combiner in the primary beam path. The combiner and folding mirror are both adjustable to allow for placing the diode aiming beam coaxial with the treatment beam.

Fiber Focus Lens - Focuses the beam into the fiber.

Blast Shield - Protects the Fiber Focus Lens from debris ejected from the proximal end of the

fiber during a fiber failure.

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4.7 SOFTWARE

There are two microprocessors in the VersaPulse Select: the main processor (Mµp) and the Safety Processor (Sµp). Each has its own software program. The two programs are not identical, but are interdependant, i.e., the software continually requires confirmation/agreement from the other processing system in order to continue its normal operating sequence. The two software programs are written to require checks with the other processing system throughout normal operation to confirm that the two systems are in agreement concerning operating parameters, system status, etc.. When either system fails to receive the expected communication with the other system, a fault condition occurs and the laser is inhibited from firing. Both processors have the ability to terminate a laser exposure. Communication is carried out through the DPRAM.

The following software sequence lists describe the operating sequence from the perspective of the main processer. The safety processor has a similar start up sequence, then monitors system operation, acting to inhibit laser firing if an abnormal operating condition is detected.

START UP & SELF TEST (main proccessor)

(Refer to the software table on 8-30)

AUTO CAL

The system performs a two point calibration for each channel to determine the relation between flashlamp voltage and pulse energy. The cap voltage values for the minimum and maximum pulse energy (.5 and 2.8) are determined, then the required voltages for other energies are derived. This is the calibration data stored in NVRAM. The values found for each channel min and max pulse energy are displayed on the second service screen.

IDLE LOOP

Check shutter position, power supplies, HVPS voltage and status, coolant, delivery fiber, BRH connector status.

Check the service switch

Check for activation of any control Check for exit to firing routine Go back to start

FIRING

When the footswitch is pressed the main proccessor calculates the appropriate flashlamp voltage using the selected pulse rate and energy to index the energy-vs-voltage curve stored in NVRAM (the calibration data). Before each fire pulse the main processor moves the servo mirror, charges the flashlamp capacitor and directs the firepulse to the appropriate flashlamp.

The fire pulse is triggered by the main processor, but the actual pulse is provided by a hardware timer. The fire pulse discharges the capacitor through the selected flashlamp, interrupts both processors, and starts a hardware timer that enables the energy monitors. After the pulse, both processors read the energy monitor signals.

Flashlamp voltage is adjusted according to the energy of the previous pulses, using a set of mathamatical formulas that generate a correction factor. This is the light feedback function.

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After each pulse, the software checks the ENG I and ENG II signals for agreement, and then confirms that the pulse energy was not excessively high or low. If any of these checks fail, the laser is inhibited from firing and a fault is displayed on the touch screen.

Pulse interval (the period between the individual laser firings) is generated by a hardware timer. Between pulses the Mµp checks flashlamp voltage, footswitch condition (is it still depressed?) and the BRH interlock. In addition it checks one of the following four values on a rotating basis (one between each pulse): +5 VDC, +12 VDC, -12 VDC, coolant temperature.

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5.0 TROUBLESHOOTING

5.1 OVERVIEW

5.1.1 Service Philosophy

The Versapulse Select is designed to require little adjustment or calibration, and to detect and report hardware malfunctions by fault code, displayed on the control panel. In most cases field failures are repaired by changing out a Field Replaceable Unit (FRU). FRU's are built specifically to support field repair, and consist of a part or group of parts determined to be suitable for field replacement. When a part fails that is a part of a FRU, the FRU is replaced, not the individual part.

Corrective and preventive maintenance must only be accomplished by a Service Engineer who has completed Coherent certification service training on the Versapulse Select.

Field calibration and adjustment is covered in detail in Section 3. Special purpose tools are required to maintain the Versapulse Select. These tools are listed in Section 6.

The entire optical path is enclosed inside the laser head. Removing the dust cover exposes the interior to foriegn matter (dust, cookie crumbs, your hands). Minimize this exposure by removing the cover only when necessary, using a clear palstic cover over the head while the dust cover is off, and getting the dust cover back on as soon as maintenance inside the head is complete.

After power up, and before the VersaPulse Select moves to its standby condition, the software performs a series of self tests. Self test failures result in fault codes displayed at the touch screen. These fault codes provide an indication of what malfunction was detected, which should point to a specific area of the system for further investigation. Explanations of the fault codes are included in this section. Most hardware malfunctions will be detected at this time.

During normal operation the software continues to monitor for system malfunctions, and to report any detected malfunctions by fault code at the touch screen.

The Versapulse Select has a series of service software routines available to the service engineer. The routines are contained in the software EPROM, and are activated by pressing a button on the Controller PCB (not accessible to the user). These routines facilitate calibration and troubleshooting. The routines are described in detail later in this section.

A service attenuator is built into the optics bench, and can be placed in the beam path by operating a switch on the Shutter PCB. The service attenuator can be used during servicing to decrease the power of the treatment beam before it enters the fiber focus assembly. This can prevent damage to an attached fiber and/or the blast shield when the laser is fired before the fiber focus alignment has been confirmed.

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The safety processor circuits include a two digit, seven segment LED display mounted on the CPU PCB. The software can use this display to indicate status or type of fault information to the service engineer.

There are two indicator bulbs inside the PFN enclosure. One bulb illuminates to indicate that the 400 VDC supply for flashlamp simmering is present. The other indicator bulb flashes at a rate proportional to the charge on the main charging capacitor.

5.1.2 Safety Precautions

Lethal voltages and Ho:YAG laser emission are the primary dangers to the Servicing Engineer. In addition to the general safety precautions which always apply when working on electronics and lasers, the Servicing Engineer must be aware of the following specific precautions:

Only Coherent certified Versapulse Select Service Engineers should attempt any service on this system.

Even with the keyswitch in the "OFF" position there are potentially lethal voltages present inside the console.

Storage capacitors inside the system are capable of holding a lethal charge, even after power has been removed from the unit.

Do not touch the YAG Cavity Module - IT IS A SHOCK HAZARD. The YAG Cavity Module is electrically isolated from the chassis ground and connected to the secondary of a transformer to develop an electrical field around the flashlamps. The YAG Cavity Module is located in the laser head.

The Ho:YAG laser light is invisible to the human eye. Because the Ho:YAG energy can not be seen, there

is no visible indication of the primary or reflected beam. Eye protection that attenuates the Ho:YAG wavelength to a safe level must be worn by all persons in the area of the laser system whenever the laser is being serviced.

The Ho:YAG laser light and its reflections are potential burn hazards and can ignite flammable materials. Use extreme caution when operating the system with covers opened or removed. The covers

contain the beam and reflections safely within the console. Only those persons required should be present during servicing, and eye protection that safely attenuates the Ho:YAG wavelength must be worn by all present.

The Ho:YAG laser light and its reflections are potential hazards to the eye. Use extreme caution when operating the system with the covers opened or removed. The covers contain the beam and reflections safely within the console. Only those persons required should be present during servicing and eye protection that safely attenuates the Ho:YAG wavelength should be worn by all those present.

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5.2 INTERIOR ACCESS & PART LOCATIONS

Interior access is gained through the front cover (door), which is hinged on the right side side. Once the front cover is opened, the top cover can be removed. Once the top cover is removed the two side panels can be removed. There is an electrical cable running between the left side panel and the console (for the key switch and emergency off button). When removing this side cover, use caution to prevent stressing the cable. A connector allows the cable to be disconnected to free the side cover completely (but the system will not turn on if this connection is broken).

Open the front cover to access the two DC power supplies (mounted inside the door), to access the Controller PCB, or to remove the top cover or either side cover.

To open the front cover, insert a small tool (such as a hex key) through the hole on the bottom left of the front cover. Push up on the tab inside the hole to release the cover (it is hinged on the right side).

FRONT DOOR CLOSED

FRONT DOOR OPENED

CONTROLLER PCB

LOW VOLTAGE

DC P/S

Insert a small tool (hex wrench) through the hole on bottom left of front door panel. Push up on the tab inside the hole to release the door. Door will swing open towards the right.

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DISPLAY P/S

FIGURE 5.1 FRONT VIEWS

TROUBLESHOOTING

5-3

TO POWER SUPPLY

To Isolated Trigger PCB

XTRM2

XTRM3

XTRM4

XTRM1

R36

To Temperature and conductivity sensors

TO HVPS

To OPTICS PLATE and FOOTSWITCH/BRH

U89 U88

TP1 - INTEGRATE TP2 - ENG1 TP3 - ENG2 TP4 - ENG3 TP5 TP6 - +5M TP7 - +12 TP8 - -12 TP9 - TEMP TP10 - COND TP11 - CAPVOLTS TP12 - DIGITAL GROUND TP13 - ANALOG GROUND

SW1

(service) SW2 (reset)

SW3 (autocal)

TROUBLESHOOTING 5-4

U52

U53

R98

up = enable down = disable

FIGURE 5.2 CPU PCB LAYOUT

SAFETY PROCESSOR

DISPLAY

To Touch Screen Display

RS232 Port

J27

To Beeper

To Servo Motor Control

To Remote Control

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AC IN

DISPLAY, DC POWER SUPPLY AND DISPLAY P/S

FUSE (5A, 250V)

DC POWER SUPPLY

DC VOLTAGES

OUT

AC IN

INTERNAL 4A, 250V LITTLE FUSE

DISPLAY POWER SUPPLY

DISPLAY

VOLTAGES

FIGURE 5.3 DISPLAY, DISPLAY POWER SUPPLY & LOW VOLTAGE POWER SUPPLY LAYOUTS

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5-5

Remove the top cover to access the laser head (optics bench), to access the coolant fill reservoir or to remove either side cover.

To remove the top cover, first open the front cover, then remove the two screws located as shown in the drawing below.

Cover lifts off

Remove these two xxx screws.

FIGURE 5.4 REMOVING THE TOP COVER

Remove optics bench cover to access the Shutter PCB, Single Solenoid PCB, Dual Solenoid PCB, Servo PCB and all of the optical component. Removing the cover exposes the optics bench to airborne contamination. The optics that operate on the YAG beam are particularly susceptable to damage associated with optics surface contamination. Remove this cover only when necessary. If the cover must be removed, be careful to minimize exposure of the optics bench interior to external contamination.

To remove the head cover, loosen the screws located along the bottom edge of three sides, then lift the cover up.

TROUBLESHOOTING 5-6

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OVERHEAD VIEW, LASER HEAD with head cover removed

2ND FOLDING

MIRROR

SERVO

PCB

SERVO AND

FIRST MIRROR

WALL

SHUTTER

PCB

SW1

OC & SECOND MIRROR WALL

SINGLE

SOLENOID

PCB

PYRO IMAGING MIRRORS

FIRST FOLDING

MIRROR

WEDGE OPTICS

YAG CAVITY MODULE (up to four cavities installed)

DUAL

SOLENOID

PCB

DIODE LASER

(AIMING)

Terminal connections for flash lamp leads.

FIBER

FOCUS

BLAST SHIELD

HR WALL

YAG IV

VIEW FROM

OC END

Nonconductive mounting plate.

CAUTION: The Cavity Module can be at a high voltage potential. Do not touch .

FIGURE 5.5 OPTICS BENCH & LASER HEAD LAYOUT

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YAG I

YAG IIYAG III

BACK SIDE TERMINAL CONNECTIONS:

ANODE OUT ANODE OUT BLANK LASER 4 CATHODE OUT LASER 3 CATHODE OUT LASER 2 CATHODE OUT LASER 1 CATHODE OUT

FRONT SIDE TERMINAL CONNECTIONS:

ANODE OUT ANODE OUT ANODE IN LASER 4 CATHODE IN LASER 3 CATHODE IN LASER 2 CATHODE IN LASER 1 CATHODE IN

TROUBLESHOOTING

5-7

YAG ROD

FLASH LAMP

HR END - (flashlamp anode RED LEAD)

O ring

FIGURE 5.6 YAG CAVITY LAYOUT

OC END (flash lamp cathode, BLACK LEAD)

End Seals

Dual Solenoid PCB

Single Solenoid PCB PCB)

J13

J14

TROUBLESHOOTING 5-8

SERVICE SWITCH

J16

(Service Attenuator)

J15

J12

Aiming Footswitch laser interlock

FIGURE 5.7 SHUTTER PCB LAYOUT

J11

(To J1 on controller

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CR3

CR2

LPT1

J17

(To J14 Shutter PCB)

Service Attenuator normally open

LP ATTENUATOR

(NOT CURRENTLY USED)

FIGURE 5.8 SINGLE SOLENOID PCB LAYOUT

LPT1

ATTENUATOR

CR4

SERVICE

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CR3

LPT3

LPT2

J18

(TO J-13 ON SHUTTER PCB)

SHUTTER

FIGURE 5.9 DUAL SOLENOID PCB LAYOUT

TROUBLESHOOTING

5-9

Remove the right side cover to access the fuses, main contactor, Isolation Transformer Terminal Board, the circuit breaker, HVPS, K1, K2, and to access the interior of the PFN enclosure.

To remove the right side cover, open the front cover, remove the top cover, remove the single screw that secures the cover at the bottom just in front of the rear wheel, then remove the six screws along the top and front of the cover (three along the top, three along the front). The cover can then be lifted off of the frame.

AC Terminal block for H pump

TOUCH SCREEN

CONTROL PANEL

SMART FAN PCB

INSIDE THE PFN COVER PLATE

Main charging Cap +

DS1

Main charging cap -

FUSE BLOCK

F2 F3

OPTICS BENCH

PFN ENCLOSURE

HVPS

F4 F5 F6 F7 F8 F9

FUSES

COOLING FAN

HEAT EXCHANGER

MAINS (F1)

MAIN RESERVOIR

AC inputs to transformer.

FILL RES.

CHASSIS

GROUNDING

POST

CIRCUIT

BREAKER

MAIN

CONTACTOR

BACK

CONDUCTIVITY SENSOR

TO XFORMER (primary)

120

100

VAC Inputs

200 VAC 220 VAC (Std.) 240 VAC

16A 16A

4A 4A 4A 4A 10A 10A

FIGURE 5.10 INTERIOR VIEW, RIGHT SIDE

TROUBLESHOOTING 5-10

10A

MAINS (F2)

120 100

All 30A @ 60Hz breaker

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Remove the left side cover to access most of the cooling system components.

To remove the left side cover, open the front cover, remove the top cover, remove the single screw that secures the cover at the bottom, just in front of the rear wheel, remove the six screws along the top and front of the cover (three along the top, three along the front), then carefully pull the cover off to access the jack and plug connection on cable that runs out to the key switch and emergency off button, both located on the cover. If the system is to be operated with the cover off, the cover will need to be placed close enough to the unit to allow the keyswitch and emergency off button connection to remain connected.

TOUCH SCREEN

CONTROL PANEL

FILL RES.

OPTICS BENCH

TEMP SENSE (DISPLAY)

FLOWSWITCH

FILTER

D/I FILTER

BACK

COOLING FAN

MAIN RESERVOIR

HEAT EXCHANGER

PFN

ENCLOSURE

FRONT

HVPS

Connector to Left Side Cover.

TEMP SENSE

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FIGURE 5.11 INTERIOR VIEW, LEFT SIDE

TROUBLESHOOTING

5-11

5.3 SERVICE MODE

The VersaPulse Select includes "service mode" software routines. Service mode provides the Servicing Engineer with a number of troubleshooting and maintenance aids. Some system faults are ignored in service mode (see

5.4.3).

To enter service mode, the main processor and safety processor must see an off to on transition of CPU PCB SW1. SW1 is the uppermost of the three switches located on the bottom left side of the CPU PCB. Note that if the switch is left on when the system is powered up, it will not enter service mode (no off to on transition). If the processors are halted (some faults are handled by halting the processor) the service switch will not work - restart the processors (press reset switch SW2 on the CPU PCB) then toggle the service switch off to on.

Upon entering service mode the touch screen displays the first service screen (see figure 5-12). The first screen includes the following functions:

AIMING BEAM CONTROL - sets the aiming beam to any of its four intensities (off, lo, med, high).

RATE CONTROL - set the firing rate from 5 to 40 Hz.

VOLTAGE CONTROL - sets the cap charge voltage from 700 to 1500 Volts.

READY/STANDBY SELECT

YAG HEAD ON/OFF SELECT - there is an on/off control for each YAG rod. Turning a rod off means that it will not be triggered during a firing sequence. This allows for operating only one rod, or any combination of rods.

Turning off a rod will result in a "skipped beat" out of each four pulses, e.g., if 40 Hz is selected with one rod turned off, the pulse interval will be normal for three pulses, and then be doubled (the rod turned off doesn't fire), then three more pulses and a double interval, and so on. The irregular interval that results from having rods turned off is easily heard.

Turning rods off effects average power and the effective pulse rate, e.g., if only one rod is on, a selected pulse rate of 40 Hz, will result in an actual pulse rate of 10 Hz, and an average power approximately one fourth that @ 40 Hz (approximate in service mode because the rods are all fired at the same cap voltage in service mode, and will have different energy outputs).

Once a rod is turned off in service mode, it remains off, even if the system is returned to user mode or turned off and then back on.

AVERAGE POWER DISPLAYS - Each time the system is fired in service mode the three energy monitor outputs are used to maintain an average power for each of the four rods. When the footswitch is released these displays will be updated, showing the average power as determined by the three energy monitors for each of the four heads. This is convenient for checking relative rod performance (all rods were fired at the same cap voltage) and for checking for agreement between the three energy monitor circuits.

NEXT SCREEN - touch to move to the second or third screen.

Press the "RESET" button if "CALIBRTE" was pressed in error.

TROUBLESHOOTING 5-12

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FIRST SERVICE MODE SCREEN

aiming beam

status

OFF

AI M MA X

AIM UP

AIM DN

AI M OF F

3.2 5 Wat ts

3.2 1 Wat ts

3.2 2 Wat ts

selected rate

5 HZ

JUMP U P RATE UP

RA TE DN

JUMP DN

0.0 0 Wat ts

selected cap

charge voltage

700 V

JUMP U P

VOLTS UP

VOLTS DN

J UMP DN

0.0 0 Wat ts

NEXT SCREEN CALIBRA TE

selected mode

(r eady or standby)

STAN DBY

0.00 Watts

READY

PARAMETER DISPLAY

TOUCH CO NTR OLS

FO R T H E PARA M E TE R

DISPLA Y ED ABOVE

THEM.

YAG HEAD SELECT/D ESELE CT

TO UC H CONTROLS

(YAG I thru IV, left to right)

AVERAGE POW ER CALCULAT ED

FROM LAST FIRING ( ENG I, II, III)

(YAG I THRU IV, right to left)

as measured by the pyro detectors

TO UC H C ON T ROL S T O MOVE

TO NEXT SCREEN, ENTER

AUTOM A T IC L AS ER

C A LIBR AT ION RO UTIN E

SECOND SERVICE M ODE SCREEN

5V 4.99 +12 1 2.00

-12 12.0 0 TEMPC 29.8 COND µS 0 .3

.5J 821 84 4 866 838

2.8J 14 21 143 3 141 1 1 4 15

NORMAL SHUTTER MODE

ENGLIS H

NEXT SCREEN

LE Att enuator

IN/O UT

PARAMETER

DIS PLA YS

CAL POINTS (M IN & MAX)

(YAG I THRU IV, lef t to r ight)

TOU CH C ONTROL & DIS PLAY

FOR SH U T T ER MODE

TOU CH C ONTROL & DIS PLAY

FOR LANGUAGE

TOUCH CONTR O L TO M OVE

BAC K TO SCREEN ONE

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5-13

CALIBRATE - touch to select the automatic laser calibration routine. "CALIBRATE" will be displayed near the top of the screen. Depress the footswitch and hold it down to start the automatic laser calibration.

During calibration the system fires the rods to find eight values - two for each rod. The values are the cap charge that will provide the lowest selectable pulse energy and the capacitor charge voltage that will provide the highest selectable pulse energy (2.8 joules). The process takes just a few seconds. After completion a message will appear on the screen indicating that the calibration is complete (the value found can be viewed on the second service screen).

The second screen provides the following functions:

5V/±12V - displays the main processor ADC measurement for the DC power supply voltages.

TEMP C - displays the coolant temperature in degrees C.

CONDUCTIVITY - displays the coolant conductivity in µS.

MIN/MAX CAP CHARGE VOLTAGES - displays the cap voltages required to obtain min pulse energy and maximum pulse energy for each head.

SHUTTER MODE - touch to select normal or service. In service mode the shutter can be moved by hand without causing a system fault. This allows the slotted optical switch outputs to be checked.

LANGUAGE - touch to select displayed language Elglish/German/French.

Note: The service mode software screens are always in English.

NEXT SCREEN - touch to go to the first screen.

5.4 FAULT ISOLATION

Failures/malfunctions fall into the following general categories:

The system fails to turn on properly, or shuts off when it should not. See section 5.4.1.

The system turns on, but the Control Panel displays and/or operating controls do not respond properly, and no fault code is displayed. See section 5.4.2

During power up tests, or during operation, the system displays one or more error codes. See section

5.4.3.

During power up self tests the system fails to pass autocalibration See Section 5.4.4

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5.4.1 TURN-ON AND SHUTDOWN FAULT ISOLATION

System "turn-on" problems occur when the system fails to turn on and stay on with activation of the key switch. System "Shutdown" refers to the system main contactor de-energizing after the system has successfully turned on.

If the system fails to turn on, determine if there is power to the unit and through the circuit breaker to the main contactor and isolation transformer. Determine if the main contactor is energizing when the keyswitch is held in the start position (do the system fan and pump start running?). If not, check the circuit breaker, isolation transformer thermal switch, front door interlock, and fuses F1/F2. If the contactor is energizing in the start position, but de-energizing when the keyswitch is released, check for sufficient coolant flow (coolant level, pump, line restrictions, etc.), waterflow switch S3, K2 and K1 (Refer to Interlock schematic in Section 8).

If the system shuts down after being turned on, and the circuit breaker is not tripping, use the Interlock schematic in Section 8 to troubleshoot the main contactor interlock loop. Note that the software and main/safety processors can not turn off the main contactor. The 24 VAC loop to the main contactor can be broken by the thermal switch in the isolation transformer, the waterflow switch, the front door interlock switch, hold on relay K2, or the fuse F3.

If the circuit breaker is tripping, check for proper transformer tapping. If the tripping is associated with firing (or charging of the main capacitor), it is probably associated with the HVPS. If not, attempt to isolate the tripping to one of the isolation transformer secondary loads by removing fuses until the circuit breaker no longer trips (smart fan fuse, pump fuse, display P/S fuse, DC P/S fuse, then interlock loop fuse). If the breaker trips with the isolation transformer primary side fuses removed, there is probably a problem with the HVPS or mains components.

5.4.2 "NO FAULT CODE REPORTED" FAULT ISOLATION

Some system malfunctions cannot be reported at the Control Panel. These include those malfunctions which interfere with the operation of the microprocessor, malfunctions in the hardware that drives the display used to report errors, and miscellaneous circuits/functions which are not directly monitored/tested by the software.

If the malfunction is associated with a particular function (e.g., the system doesn't respond to the footswitch, or to some front panel control), troubleshoot that function, referring to the circuit descriptions in Section 4.

If the system turns on, but the malfunction is more general (e.g., the self test sequence doesn't run, Control Panel does not respond) check for proper DC power supply voltages, isolation transformer tapping, interconnection problems, or for some problem with the microprocessors (are they running?)/Control Panel interface. If the problem can not be isolated to a particular circuit, replace the CPU PCB.

5.4.3 "FAULT CODE REPORTED" FAULT ISOLATION

The safety processor monitors the system to detect and respond to various fault conditions. When a fault is detected, the safety processor displays the fault directly on the CPU PCB (as a two digit hexadecimal number on the two seven segment LED's) and notifies the main processor of the fault. The main processor updates the touch screen to display the fault code and any accompanying message at the touch screen. Multiple faults are displayed sequentially, and repeatedly.

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TROUBLESHOOTING

5-15

These fault conditions can be informational, clearable, or permanent.

Informational faults notify the user of some detected abnormal condition that is not significant enough to interfere with system operation. An advisory message is displayed on the touch screen and the system continues to operate.

Clearable faults interrupt system operation and force the system to STANDBY, but have the potential to be cleared by some user action. Some clearable faults include messages to indicate an action required by the user, e.g., "ATTACH FIBER" appears on the touch screen if there is no fiber attached. Other clearable faults advise of some detected abnormal condition, but require no further action by the user other than selecting READY to clear the error. Finally, the coolant conductivity and overtemperature errors will not clear until that parameter falls back into acceptable limits. The user can't clear these faults directly. Note that a clearable fault will return if the condition that caused it occurs again or is still active.

Permanent faults place the system in a safe, nonfiring condition that can not be cleared without re-starting the system. Restarting the system will clear the fault, but if the detected condition is still present, the fault will occur again.

Some faults are ignored in service mode to aid in troubleshooting. Some faults are only checked during the self test sequence that occurs at start up. Such faults are so identified in the description of the fault.

Begin by getting a detailed understanding of the symptoms. For example, does the fault appear during self testing or during normal operation; Does the fault occur only when firing; Only at certain energy or pulse settings; is the fault easily repeatable or is it intermittent? It is always worthwhile to check for proper mains input, proper transformer tapping, proper DC voltage supply outputs, and to perform a careful visual inspection for loose connections and visual indications of problems.

The following list defines the fault codes and provides troubleshooting information for each. The two characters in parentheses following the bold text is the hexadecimal number that appears on the CPU PCB display when the fault occurs. Clearable faults are cleared by pressing seleting READY.

F1 - ADC REMAINS BUSY TOO LONG - The CPU PCB analog to digital convertor (U20) or its associated circuitry is malfunctioning. Check DC voltages, connections to the CPU PCB. If problem persists, change the CPU PCB.

F2 - UART DETECTED BREAK CONDITION - The CPU PCB main processor UART (U29) is detecting an abnormal condition on at least one of its receive ports. The display and remote control receive and transmit data to the Main Processor UART. This could be a problem with the CPU PCB, Remote Control, or Display.

F3/4 - DIGITAL I/O FAILURE - The main processor digital I/O is malfunctioning (F3 is U43, F4 is U44).

F5 - CAP VOLTS WRONG - The output of main processor DAC U10 is used as the charge level command to the

HVPS. The main processor writes a digital value to the DAC, then checks the DAC output through its ADC circuit to insure that the DAC output is correct. If not, this error occurs. If this error persists, change out the CPU PCB. If another lamp fires out of sequence due to noise the cap will not have the correct charge. This error will (or may) occur. Check the trigger board for ground line and diode modifications. The white wire on the J53 connector may have to be removed.

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F6 - COOLANT CONDUCTIVITY WRONG - The coolant conductivity is monitored to minimize corrosion inside the coolant system. If the coolant conductivity is excessive, this fault will occur. This fault may occur if a system is turned on after being off for an extended period, the water added as coolant is not deionized, something inside the coolant loop is contaminating the coolant, or the DI filter needs to be replaced. If the fault occurs at turn on, leave the system on; this allows the DI filter to lower the coolant conductivity. If this fault persists, change the DI filter.

F7 - COMMUNICATION DATA ERROR - Not implemented in current software.

F8 - CPU ERROR - The Main Processor has failed. Check the DC supply voltages. If the fault persists, change

out the CPU PCB.

F9 - INCORRECT ECHO OF TRANSMITTED CHARACTER - Not implemented in current software.

F10 - E1 AND E2 DISAGREE - After a fire pulse, the voltage signals from the two energy monitor circuits E1 and

E2 are different. When properly calibrated, both circuits will output ≈ x VDC/joule of energy. Check the energy monitor calibration. The two signals can be seen on an oscilloscope at CPU PCB test points (TP2 TP3). Both pyrodetectors are located on the Single Solenoid PCB. The samples are picked off the main beam path (2.22V/ Joule) by a wedge optic, then directed to the pyrodetector surface through an imaging mirror.

F11 - ERROR PROCESSOR ERROR - The error processor is actually a software routine. If this error persists change out the CPU PCB.

F12 - SPURIOUS FIRE PULSE INTERRUPT - A fire pulse interrupt has occurred when none was expected. This does not indicate that any laser energy has been produced, but just that the fire pulse signal as read by the main processor interrupt circuit has seen the /FIREPULSE/ line go active. If this problem persists, replace the CPU PCB.

F13 - UART DETECTED FRAMING ERROR - The CPU PCB main processor UART (U29) is detecting an abnormal condition on at least one of its receive ports. The display and remote control receive and transmit data to the Main Processor UART. This could be a problem with the CPU PCB, Remote Control, or Display.

F14 - HVPS ERROR - The HVPS has reported one of its three faults to the CPU PCB. The three faults are temperature overload, current overload, or no charge reversal.

F15 - MAIN PROGRAM DEAD - This fault indicates a problem on the CPU PCB. Swap out EPROMs.

F16 - NEGATIVE 12 VDC WRONG - Check/adjust the -12 VDC.

F17 - NONEXISTENT ERROR CODE - Change out the CPU PCB if this fault persists.

F18 - UART DETECTED OVERRUN ERROR - The CPU PCB main processor UART (U29) is detecting an

abnormal condition on at least one of its receive ports. The touch screen and remote control receive and transmit data to the Main Processor UART. This could be a problem with the CPU PCB, remote control, or touch screen.

F19 - POSITIVE 5 VDC WRONG - Check/adjust the 5 VDC.

F20 - UART DETECTED PARITY ERROR - The CPU PCB main processor UART (U29) is detecting an abnormal

condition on at least one of its receive ports. The touch screen and remote control receive and transmit data to the main processor UART. This could be a problem with the CPU PCB, remote control, or touch screen.

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5-17

F21 - POSITIVE 12 VDC WRONG - Check the +12 VDC.

F22 - ROM CRC CHECK FAILED - This check is done during self test only. Software EPROM has failed the self

test. If this fault persists change out the CPU PCB or swap out the EPROMs.

F23 - SAFETY RELATED DATA ERROR - If this fault persists, change out the CPU PCB.

F24/F25 - SHUTTER DRIVE STUCK ON/OFF - These two checks are done during the self test sequence. Refer

to figure 4.2 (in Section 4). Stuck on indicates that the SHTR DR SNC line is at 24 VDC when the SHTR DR signal is not active (The Q2 transistor is on when it should not be). Stuck off indicates that the SHTR DR SNC line is not at 24 VDC when the SHTR DR signal is active (the Q2 transistor is not on when it should be).

F26 - SERVO ERROR - This check is done during self test only. The servo controller has test operated the servo system and found a problem. This could be a problem with the 24 VDC supply voltage, the Servo Amp PCB, the motor, the position sense, or the CPU PCB.

F27 - SOFTWARE ERROR - If this error persists, replace the software EPROMs or CPU PCB.

F28/29 - SAFETY SHUTTER NOT CLOSED/OPENED - The safety shutter SHTR DR SNC line has indicated that

the shutter voltage is present (shutter open) or not present (shutter closed) when it should not be. This could be a problem with the safety shutter (Dual Solenoid PCB), Shutter PCB, footswitch, CPU PCB or the 24VDC supply.

F30/31 - not used

F32 - CAP FEEDBACK WRONG - This check is done during self test only. The DAC output is ramped up through

its range of operation, and read back through the ADC across the range. If the ADC readback differs from the command sent to the DAC, this error occurs. If the error persists, change out the CPU PCB.

F33 - HCTL SERVO CONTROLLER BUSTED - This check is done during self test only. CPU PCB U30 (the servo controller) has failed its self test. If this error persists, replace the CPU PCB.

F34 - DPRAM DATA INCORRECT - The dual port RAM has a problem. If this fault persists, replace the CPU PCB.

F35 - NOFIRE - The /NOFIRE/ signal has been asserted.

F36 - SAFETY PROCESSOR ERROR - If this fault persists, replace the CPU PCB.

F37/F38 - ENERGY HIGH/LOW - The energy of a single pulse is more than two times (F37) or less than half (F38)

of the requested energy.

F39 - NO LASER ENERGY -

F40/41 - PULSE RATE HIGH/LOW - The pulse rate is more than twice of that requested (F40) or less than half

of that requested.

F42 - UNEXPECTED FIRE PULSE - A fire pulse was detected when one was not expected. If this fault persists, replace the CPU PCB.

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F43 - DPRAM HANDSHAKE FAILURE - The dual port RAM has a problem. If this fault persists, replace the CPU PCB.

F44 - MAIN PROCESSOR & SAFETY PROCESSOR FIRING PARAMETER MISMATCH - Replace the CPU PCB if this fault persists.

F45 - DPRAM FAILED TEST - This check is done during self test only. The dual port RAM has a problem. If this fault persists, replace the CPU PCB.

F46 - ATTACH FIBER - Attach the fiber to clear this fault.

F47 - ATTACH FOOTSWITCH - Attach the footswitch to clear this fault.

F48 - CHECK FOOTSWITCH - This check is done during self test only. The footswitch is depressed during self

testing. (This may also be reported if the footswitch is pressed during turn on or system initialization).

F49 - SYSTEM INACTIVE - The system goes to STANDBY if left in READY for five minutes without use. (This is not a fault).

F50 - REMOTE INTERLOCK - The remote interlock loop is not completed.

F51 - NO CONTROL PANEL - The touch screen display is not responding. Check cable connections, the display

power supply, the touch screen display, and the CPU PCB.

F52 - OVERHEATING - This fault occurs when coolant temperature reaches 35˚C and resets when temperature falls back down to 32˚C. The temperature monitoring circuit is calibrated as outlined in Section 3. Check Smart Fan PCB, Fan motor, pump, and water level. Calibrate the TEMP set on the CPU PCB.

F53/F54 - PERFORMING SELF TEST/SEMAPHORE - Not error codes

F55 - NOT CALIBRATED - This check is done during self test only. The system doesn't have calibration data

stored in memory. The auto calibration routine must be run.

F56 - FAILED ENERGY SAFETY TEST - This check is done during self test only. The safety processor failed to detect a forced incorrect pulse energy level during self test. The test includes a forced >2 times requested energy and forced less than half requested energy. The safety processor must detect and respond to both., or this fault will occur. If this fault persists, check the power out of the system, check the energy monitor circuit calibration, run the autocalibration. (This may be related to fault 5).

F57 - FAILED INTERVAL SAFETY TEST - This check is done during self test only. The system failed to detect a forced incorrect pulse interval during self test. The test includes forced .8 times and 1.2 times requested pulse intervals. The safety processor must detect and respond to both, or this fault will occur. Replace the CPU PCB if this error persists.

F58 - NVRAM CHECKSUM - This check is done during self test only. The NVRAM has failed a checksum check during self testing. If this fault persists, replace the CPU PCB. The Lithium battery in NVRAM could be expired or +5V too high. Check the power supply.

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F59 - SYSTEM DATA INCORRECT - This check is done during self test only. There is a disagreement the software EPROM version installed and the information on EPROM software version stored in NVRAM.

F60 - ENERGY MONITOR ERROR - The safety processor and main processor have had a conflict in the shared use of the energy monitor circuits. Replace the CPU PCB if the fault persists.

F61 - PROGRAM FLOW ERROR - Replace the CPU PCB if this fault persists.

F62/63 - ENERGY 20% HIGH/LOW - (information only, active in service mode)

F64/65 - RATE 20% HIGH/LOW - (information only, active in service mode)

F66 - FRONT PANEL COMMUNICATIONS TIME OUT - The front panel has not responded in time to a query

from the main processor.

F67 - SOFTWARE TIMING - A firing pulse has been missed because the software did not complete all the tasks necessary in time for the correct pulse interval.

F68 - BLAST SHIELD IS NOT INSERTED - The microswitch that detects the blast shield position is indicating that the blast shield is not inserted.

F69 - ONE OR MORE FLASHLAMPS NOT LIT - (permanent, active in service mode)

F70 - NOFIRE TEST FAILED - (pemanent, active in service mode)

F71 - AUTOCALIBRATION DISABLED - SW3 is in the down position.

F72 - SERVICE ATTENUATOR IN THE BEAMPATH - The service attenuator is energized. The service

attenuator is controlled by a switch mounted on the Shutter PCB.

F77 - LOW ENERGY ATTENUATOR COATING DAMAGED - With the low energy monitor in the beam path, the energy measured at the low energy attenuator output is not 40% of the energy measured at the input. Press READY to clear this fault.

F78 - THE SYSTEM TRIED TO FIRE THE WRONG LASER - Press READY to clear this fault.

F79 - OVERTIME - A timed exposure exceeded its time limit. Press READY to clear this fault code.

F80 - ATTACH HOLMIUM FIBER - Holmium is selected, but the fiber attached is not recognized as the smart

fiber (Hall effect does not sense magnetic field).

F81 - LOW ENERGY ATTENUATOR NOT IN CORRECT POSITION - The position sensors (slotted optical switches) indicate the low energy attenuator is not in the correct position. Press READY to clear this fault code.

F82 - FAILED TO DETECT A FORCED OVER EXPOSURE - Detected during self test. Restart the system to clear this fault code.

TROUBLESHOOTING 5-20

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F83 - FAILED TO DETECT A FORCED INCORRECT LASER FIRING - Detected during self testing. Restart the system to clear this fault code.

F86 - CHANNEL 1 IS TURNED OFF - Cycle the system off/on to re-enable channel 1 or continue to use the system at a reduced pulse rate. If cal. volts is less than 1450 VDC, the fault may be caused by a noise related problem. If this fault persists check the channel optics, alignment, flash lamp and rod.

F87 - CHANNEL 2 IS TURNED OFF - Cycle the system off/on to re-enable channel 2 or continue to use the system at a reduced pulse rate. If cal. volts is less than 1450 VDC, the fault may be caused by a noise related problem. If this fault persists check the channel optics, alignment, flash lamp and rod.

F88 - CHANNEL 3 IS TURNED OFF - Cycle the system off/on to re-enable channel 3 or continue to use the system at a reduced pulse rate. If cal. volts is less than 1450 VDC, the fault may be caused by a noise related problem If this fault persists check the channel optics, alignment, flash lamp and rod.

F89 - CHANNEL 4 IS TURNED OFF - Cycle the system off/on to re-enable channel 4 or continue to use the system at a reduced pulse rate. If cal. volts is less than 1450 VDC, the fault may be caused by a noise related problem If this fault persists check the channel optics, alignment, flash lamp and rod.

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6.0 SELECTED PARTS

The Bill of Materials for the VersaPulse Select series is maintained under document control at Coherent Medical Group in Palo Alto, California, and is subject to change. The following list is provided for convenience - always confirm the P/N for a given part through Technical Support before ordering.

0623-002-01 ASSY, FIBER FOCUS, MACHINED HEAD, Er ONLY 0623-846-01 ASSY, FIBER FOCUS, MACHINED HEAD, Ho ONLY, FRU 0619-409-01 BEZEL, FRONT, WHITE (AROUND THE DISPLAY PANEL)

BLASTSHIELD, Er, VPSEL, FRU 0624-015-01 BLASTSHIELD, Ho/Nd, VPSEL, FRU 5108-0120 BREAKER, CIRCUIT, 30A, 250V 0619-668-01 BUMPER, FRONT DOOR 0621-057-01 BUMPER, SIDE PANEL 5102-0123 BUTTON, SWITCH, RED, EMERGENCY OFF 6008-0026 CABLE, FIBER OPTIC, 9FT 6001-1473 CABLE, HIGH VOLTAGE, 30kV (PFN TO LASER POD) 1504-0178 CAPACITOR, 2.0kVDC, PFN, CHARGING, Ho/Nd 1504-0179 CAPACITOR, 3.5kVDC, PFN, CHARGING, Er 2601-0145 CAPACITOR, MOTOR, FAN 0613-783-01 CARTRIDGE, DEMINERALIZER, WATER 2603-0124 CARTRIDGE, FILTER, PARTICLE, WATER, 5 MICRON 1407-0161 CASTER, SWIVEL, 2.5” DIA 1407-0163 CASTER, SWIVEL, 3.5” DIA, MOBILE LASER 0622-989-01 CAVITY, BRICK, Er:YAG, VPSEL 0622-815-01 CAVITY, BRICK, Ho:YAG, VPSEL, FRU 0623-637-01 CAVITY, BRICK, Nd:YAG, VPSEL, FRU 0622-988-01 CAVITY, BYPASS, VPSEL 4501-0457 CONTACTOR, MAIN 6005-0098 CORD, POWER, 8/3, 25' 0619-408-01 COVER, DISPLAY, REAR 0619-907-01 COVER, TOP, W/HANDLE 0625-963-01 DISPLAY, AC PLASMA, WITH POWER SUPPLY, VPSEL, FRU 0621-331-01 DOOR, FRONT 0621-588-01 FAN, COOLING, MOTOR AND IMPELLOR 0622-418-01 FILTER, AIR, VPSEL, FRU 0619-450-01 FLASHLAMP, XENON, WITH LEADS 0624-588-01 FOOTSWITCH, DUAL, VPSEL 0622-421-01 FOOTSWITCH, VPSEL, FRU 5110-0280 FUSE, 1/2A, PICO 5110-0281 FUSE, 10A, 250V, S/B, 5X20MM 5110-0294 FUSE, 16A, 250V, S/B, 5X20MM 5110-0254 FUSE, 4A, 250V, S/B, 5X20MM 5111-0124 FUSE BLOCK 0619-067-01 GLASSES, LASER, 1.06/2.12/2.9 0619-066-01 GOGGLES, LASER, 1.06/2.12/2.9

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0619-411-01 HANDLE, FRONT DOOR 0619-397-01 HEAT EXCHANGER 2603-0136 HOUSING, FILTER, WATER, 1/2NPT, CLEAR#5 0622-537-01 INDUCTOR, CAN, VPSEL, FRU 0619-353-01 INDUCTOR, PFN 5107-0163 KEY, TURN ON/OFF 0623-629-01 KIT, UPGRADE, WHEEL, MOBILE, FRU 0621-115-01 LASER, DIODE, AIMING, 650NM

LENS CELL, Er, CAST HEAD 0624-017-01 LENS CELL, Ho ONLY, CAST HEAD, FRU 0622-771-01 LENS CELL, Ho, MACHINED HEAD, FRU 0624-016-01 LENS CELL, Ho/Nd, CAST HEAD, FRU 0622-985-01 LENS, BEAM COMBINER, Er 0623-501-01 LENS, BEAM COMBINER, Ho/Nd 0622-978-01 MIRROR, FIRST RELAY, Er 0623-494-01 MIRROR, FIRST RELAY, Ho/Nd 0622-981-01 MIRROR, FOLDING, Er 0623-497-01 MIRROR, FOLDING, Ho/Nd 0622-975-01 MIRROR, HR, Er 0619-381-01 MIRROR, HR, Ho 0623-491-01 MIRROR, HR, Nd 0622-983-01 MIRROR, IMAGING, PYRO, Er 0623-499-01 MIRROR, IMAGING, PYRO, Ho/Nd 0622-977-01 MIRROR, OC, Er 0619-383-01 MIRROR, OC, Ho 0623-493-01 MIRROR, OC, Nd 0622-979-01 MIRROR, PLANO, Er 0619-385-01 MIRROR, PLANO, Ho 0623-495-01 MIRROR, PLANO, Nd 3501-0143 MOTOR, PUMP, WATER, 230VAC, 50/60Hz 0619-451-01 MOTOR, SERVO, WITH ENCODER, VPSEL 0621-634-01 MOUNT, POD, INSULATED, G-10, CAST HEAD 0621-600-01 MOUNT, POD, INSULATED, G-10, MACHINED HEAD 0622-450-01 NUT, LOCK, OPTIC MOUNT SCREW, CAST HEAD 0619-964-01 NUT, LOCK, THICK, OPTIC MOUNT SCREW, MACHINED HEAD 0619-964-02 NUT, LOCK, THIN, OPTIC MOUNT SCREW, MACHINED HEAD 2502-1137 O-RING, BRICK 2503-2126 O-RING, LAMP 2503-2136 O-RING, ROD 0623-500-02 OPTIC, ATTN, LOW ENERGY, Ho/Nd 0622-984-01 OPTIC, ATTN, LOW ENERGY/SERVICE/SHUTTER, Er 0623-500-01 OPTIC, ATTN, SERVICE/SHUTTER, Ho/Nd 0622-987-01 OPTIC, BLASTSHIELD, Er 0623-502-01 OPTIC, BLASTSHIELD, Ho/Nd 0622-982-01 OPTIC, WEDGE, FIRST, Er 0623-498-01 OPTIC, WEDGE, Ho/Nd 0622-982-02 OPTIC, WEDGE, SECOND, Er 0626-462-01 PANEL, LEFT, SIDE, FRU 0626-461-01 PANEL, RIGHT, SIDE, FRU 0622-444-01 PCB, CONTROLLER, FAN SPEED, DIFF, VPSEL 0623-156-01 PCB, CPU, Er, VPSEL 0623-841-01 PCB, CPU, Ho/Nd, VPSEL 0623-338-01 PCB, DAUGHTER, (USE WITH 0623-841-01 ONLY) 0623-001-01 PCB, DUAL SOLENOID, Er, VPSEL 0619-333-01 PCB, DUAL SOLENOID, Ho/Nd, VPSEL 0619-280-01 PCB, SERVO AMPLIFIER, VPSEL

SELECTED PARTS 6-2

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0619-331-01 PCB, SHUTTER, VPSEL 0623-000-01 PCB, SINGLE SOLENOID, Er, VPSEL 0619-332-01 PCB, SINGLE SOLENOID, Ho/Nd, VPSEL 0621-561-01 PCB, TRIGGER, ISOLATED 0622-993-01 PFN/MUX, Er 0623-845-01 PFN/MUX, Ho/Nd, FRU 0625-962-01 PLUG, BRH, FRU 0623-847-01 POD, Ho (4 BRICK), CAST HEAD, FRU 0623-165-01 POD, Ho (4 BRICK), MACHINED HEAD, FRU

POD, Ho (3 BRICK)/Nd (1 BRICK), FRU 0622-851-01 PUMP/MOTOR, WATER, FRU 3501-0141 PUMPHEAD, WATER, 4gpm@100psi 1403-0039 RAIL, MOUNT, HVPS 3701-0073 RCVR, INFRARED (ON TRIGGER BOARD) 4501-0460 RELAY, DPDT, 12VAC (K1 TURN ON) 4501-0461 RELAY, DPDT, 24VAC (K2 WATER FLOW) 0626-460-01 REMOTE CONTROL W/STORAGE 0626-434-01 REMOTE CONTROL PANEL, FRU 0622-976-01 ROD, Er:YAG, TESTED 0619-382-02 ROD, Ho:YAG, TESTED 0623-492-01 ROD, Nd:YAG, TESTED 0622-066-02 SCREW, ADJUST, OPTIC, LONG, CAST HEAD 0619-094-01 SCREW, ADJUST, OPTIC, LONG, MACHINED HEAD 0622-066-01 SCREW, ADJUST, OPTIC, SHORT, CAST HEAD 0619-094-02 SCREW, ADJUST, OPTIC, SHORT, MACHINED HEAD 7502-0810 SCREW, SOCKET HEAD, NYLON 8-32X5/8 (FOR G-10 POD MOUNT) 0622-540-01 SENSOR, AIR TEMP, FAN, VPSEL 2603-0096 SENSOR, CONDUCTIVITY 4803-0743 SENSOR, WATER TEMP, CPU, BARE TRANSDUCER 0622-539-01 SENSOR, WATER TEMP, FAN, HARNESS, VPSEL 0622-541-01 SMART FAN, VPSEL, FRU 2504-0012 SNAP RING, BLASTSHIELD 0624-145-01 SOFTWARE, 20W Ho/60W Nd, VPSEL 0622-959-01 SOFTWARE, 22.5W Ho, VPSEL, FRU 0622-422-01 SOFTWARE, 45W Ho, VPSEL 0624-067-01 SOFTWARE, 45W Ho/60W Nd, VPSEL 0621-683-01 SOFTWARE, 60W Ho, VPSEL 0623-585-01 SOFTWARE, 60W Ho/60W Nd, VPSEL 0622-721-01 SOFTWARE, 80W Ho, VPSEL, FRU 0623-144-01 SOFTWARE, Er, VPSEL 2204-0004 SOLENOID, ROTARY, 24V 2509-0306 SPRING, MOUNT, OPTIC 0622-420-01 SUPPLY, POWER, HIGH VOLTAGE, Ho or Er, FRU 0623-649-01 SUPPLY, POWER, HIGH VOLTAGE, Ho/Nd, FRU 4001-0202 SUPPLY, POWER, LOW VOLTAGE, +5/+12/-12/+24 0621-576-01 SUPPLY, POWER, SIMMER, 400VDC, Ho/Nd 5102-0114 SWITCH, EMERGENCY OFF, BARE BASE (NOT WIRED, W/O BUTTON) 0624-631-01 SWITCH, FLOW, WATER, FRU 5107-0159 SWITCH, KEY, 3 POS, 2 POLE (NOT WIRED) 0619-443-01 TANK, WATER, LOWER, VPSEL 0621-176-01 TANK, WATER, UPPER, VPSEL 4802-0638 THYRISTOR, 1800V, 160A 0622-919-51 TOOL, ALIGNMENT, 10MM APERTURE, CAST HEAD 0622-905-51 TOOL, ALIGNMENT, 10MM APERTURE, MACHINED HEAD 0621-131-51 TOOL, ALIGNMENT, CROSS-HAIR, 1/2” HOLE 0622-782-51 TOOL, ALIGNMENT, SERVO MIRROR, CAST HEAD

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0622-543-51 TOOL, ALIGNMENT, SERVO MIRROR, MACHINED HEAD 0614-868-51 TOOL, DETECTOR, FIBER, TRANSIMPEDANCE 0615-103-51 TOOL, FIBER INPUT, 200µm 0624-209-01 TOOL, FIBER, TEST, ERBIUM 0623-973-01 TOOL, FIBER, TEST, POWER 0621-675-01 TOOL, FIBER, TEST, SMA (THE BURN FIBER) 0623-171-51 TOOL, MICROSCOPE, INSPECTION, FIBER 5601-0180 TRANSFORMER, TRIGGER, 30kV, PFN 0622-440-01 WATER, DI, 2.5GAL, VPSEL, FRU 0623-629-01 WHEELS, MOBILE, UPGRADE, FRU 1407-0150 WHEEL, REAR, STANDARD 1407-0164 WHEEL, REAR, MOBILE LASER 3701-0072 XMTR, INFRARED (ON CPU BOARD) 4801-0402 XSTR, FET, 60V, VN2222LL

SELECTED PARTS 6-4

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8.0 SCHEMATICS AND DRAWINGS

This section includes a complete set of schematic diagrams for the Versapulse Select as produced at the release of this manual, as well as selected drawings.

TITLE FROM DWG. # PAGE

INTERLOCK SCHEMATIC 0621-295-01 8-2

SIGNAL INTERCONNECT N/A 8-3

CONTROLLER PCB 0619-334-81 8-4 Thru 11

SHUTTER PCB 0619-331-01 8-12

DUAL SOLENOID PCB 0619-333-01 8-13

SINGLE SOLENOID PCB 0619-332-01 8-14

SERVO AMP PCB 0619-280-01 8-15

ISOLATED TRIGGER PCB 0621-561-01 8-16

DIFFERENTIAL FAN SPEED

CONTROLLER 0622-444-01 8-17

SIMPLIFIED BLOCK DIAGRAM N/A 8-18

CONTROLLER PCB (REV. B) 0623-841-XX 8-19 Thru

8-27

DAUGHTER PCB 0623-338-01 8-28

REMOTE PCB 0619-426-01 8-29

SOFTWARE TROUBLESHOOTING

TABLE 8-30

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This section is single sided page numbered.

SCHEMATICS

8-1

VersaPulse Select Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual