laser mechanisms, inc. - universal-hsu · 2017-04-19 · laser mechanisms, inc.’s cutting heads...

Universal-HSU With Basic+ Interface Operation Manual

PLMNL0227 REV. C i Universal-HSU (with Basic+ Interface) Manual

WARNING

WORKING AROUND HIGH-POWERED LASERS CAN BE DANGEROUS

Laser Mechanisms, Inc.’s cutting heads must never be operated without the cutting head interlock switch being connected. The switch should be CLOSED when the head is properly attached. In the event of a crash or the cutting head becomes dislodged from its normal operating position, the switch will OPEN. This interlock switch must be connected in a circuit in such a way that it will immediately turn off the laser and stop all machine motion. Check the wiring diagrams for your system.

Serious personal injury and/or equipment damage can occur if the head becomes dislodged and:

The head interlock is not connected properly.

Any interlock in the Laser Mechanisms’ product or laser system is defeated.

Laser Mechanisms, Inc. assumes no responsibility or liability for interlock switches or circuits and all interlocks are the sole responsibility of the purchaser of this head.

All wiring should be done by personnel knowledgeable in electrical wiring and in accordance with the national and local electrical codes.

DISCLAIMER

The information in this manual is subject to change without notice.

Laser Mechanisms, Inc. makes no warranty of any kind with regard to the material in this manual, including but not limited to, the warranties or merchantability and fitness for a particular purpose.

Laser Mechanisms, Inc. shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing, performance or use of this product.

Corporate names and trademarks stated herein are the property of their respective companies.

COPYRIGHT

©2015 Laser Mechanisms, Inc. All rights reserved. No part of this publication may be reproduced in any form, or by any means without the prior written permission of Laser Mechanisms, Inc.

PRODUCT WARRANTY

Laser Mechanisms, Inc. warrants this product against defects in material and workmanship for a period of one year from the date of shipment from Laser Mechanisms Inc. or an authorized distributor. During the warranty period, Laser Mechanisms, Inc. will at its option, repair or replace products that prove to be defective.

For all products returned to Laser Mechanisms, Inc. for warranty service the customer must:

Call Laser Mechanisms, Inc. for a Return Material Authorization (RMA) number.

Properly pack the product with the RMA number on the outside of the package. Include in the package all cables and all accessories shipped with the product along with a description of the problem.

Prepay shipping charges to Laser Mechanisms, Inc.

Insure the shipment in case of loss or damage. Laser Mechanisms, Inc. will not accept any liability in case of damage or loss.

Laser Mechanisms, Inc. will pay the shipping charges, duties and taxes for the products returned to Laser Mechanisms, Inc. from outside the United States.

The foregoing warranty will not apply if damage is incurred resulting from improper or inadequate maintenance by the customer, unauthorized modifications or misuse, operation of the product outside its specifications, interlocks not connected properly, improper site preparation, parts or assemblies not supplied by Laser Mechanisms, Inc. or unauthorized repair by non-Laser Mechanisms, Inc. authorized personnel.

For complete warranty information visit our web site at www.lasermech.com.

PLMNL0227 REV. C ii Universal-HSU (with Basic+ Interface) Manual

INITIAL INSPECTION

Inspect all shipping containers for damage as soon as the device arrives. It is your responsibility, the recipient, to notify the freight company of any damage. The freight company will require you to provide the container that any goods were shipped in, all shipping documentation and a list of all damages. Photographs of the damage are helpful in settling a freight claim.

Do not return damaged goods to the factory without a Return Material Authorization Number (RMA number).

Although it is Laser Mechanisms, Inc.’s intent to insure you are up and running as soon as possible, damage incurred during shipment must be settled with the freight company before arranging for repairs or replacement. No return shipments will be accepted without an RMA number clearly printed on the outside of all shipping containers. Failure to follow this procedure could void any warranty coverage on your head. Call your sales engineer at Laser Mechanisms, Inc. for a RMA number.

Carefully remove the device from its shipping container and all packing material to avoid damage. Save all packaging material in the event the head requires shipping or storage.

Check all items received against the packing list to verify that all the items were received.

Please note the product you receive may differ slightly from the illustrations in this manual. While the drawings may differ, the basic procedures described within remain the same.

TERMS USED IN THIS MANUAL

WARNING: The user could be injured if the warning is not followed.

CAUTION: The device or system could be damaged if the CAUTION is not followed.

NOTE: Clarification of a step or steps.

SAFETY

WARNINGS: Follow all warnings in this manual.

SAFETY GLASSES: Everyone in the area where the laser is being used must wear laser safety glasses designed for the laser being used.

SECONDARY REFLECTIONS: Secondary reflections are dangerous; never expose any part of your body to a reflected laser beam.

INTERLOCKS: Interlocks are safety devices and should never be defeated.

ADJUSTMENTS: Always turn off or put the laser in standby before making any adjustments to beam delivery components.

BEAM DUCT: Never open any component of the beam duct while the laser is operating. Always turn the laser off before servicing any beam duct components.

MANUALS: Always read the instruction manuals before attempting to install or make adjustments to any beam delivery component.

PLMNL0227 REV. C iii Universal-HSU (with Basic+ Interface) Manual

TABLE OF CONTENTS

1 Introduction ........................................................................................................................ 1

2 Installation .......................................................................................................................... 2 2.1 Electrical Grounding and Noise .......................................................................................................... 2

2.2 Interface Box Mounting ....................................................................................................................... 2

2.3 Connections ........................................................................................................................................ 3

2.3.1 TB1 – Supplied Power......................................................................................................3

2.3.2 TB2 – Laser System Interface ..........................................................................................3

2.3.3 Micro USB Connector.......................................................................................................3

2.3.4 HSU Interface Cable ........................................................................................................3

3 Basic+ HSU Interface Signals ........................................................................................... 4 3.1 VHSU Standoff (Analog Out) ................................................................................................................. 4

3.2 VREF (Analog Input) ............................................................................................................................. 4

3.3 VDIF (Analog Output) ........................................................................................................................... 4

3.4 Ready (Digital Output) ........................................................................................................................ 4

3.5 Touch (Digital Output) ......................................................................................................................... 4

3.6 Status (Digital Output) ........................................................................................................................ 5

3.7 Calibrate (Digital Input) ....................................................................................................................... 5

4 Basic+ HSU Utility .............................................................................................................. 6 4.1 Introduction ......................................................................................................................................... 6

4.2 Connecting .......................................................................................................................................... 6

4.3 HSU Panel .......................................................................................................................................... 7

4.4 Settings ............................................................................................................................................... 7

4.4.1 Active Curve .....................................................................................................................8

4.4.2 Offset ................................................................................................................................8

4.4.3 Averaging Sample ............................................................................................................8

4.4.4 Gain ..................................................................................................................................8

4.5 Basic+ Panel ....................................................................................................................................... 9

4.5.1 TRA Selection ..................................................................................................................9

4.6 Advanced Menu ................................................................................................................................ 10

PLMNL0227 REV. C iv Universal-HSU (with Basic+ Interface) Manual

5 Example of Integrating the HSU to a PLC/CNC.............................................................. 11 5.1 In-Position ......................................................................................................................................... 11

5.2 Run/Hold ........................................................................................................................................... 11

5.3 Calculating the Standoff Error ........................................................................................................... 12

5.4 Setting the Drive Command on Tip-Touch ....................................................................................... 12

6 Interface Specifications ................................................................................................... 13

7 Troubleshooting ............................................................................................................... 17

8 Appendix A – Replacement of Basic Interface with Basic+ Interface .......................... 19

PLMNL0227 REV. C 1 Universal-HSU (with Basic+ Interface) Manual

1 Introduction

The Basic+ Height Sensing Unit (HSU) Interface is the connection point between your laser system controller and the height sensing unit of the laser head.

The Basic+ HSU Interface features (See Figure 1):

Compact, electrically-shielded, sturdy enclosure ~ (67mm x 89mm x 31mm)

Micro-USB port for HSU diagnostics and for adjustment of settings

Servo command signal with adjustable gain

Ground integrity circuit

Optically isolated digital I/O (sinking or sourcing)

Current limited analog outputs

Removable terminal blocks for easy installation

Basic+ HSU Utility software with friendly graphical user interface

The Basic+ Interface in combination with the Laser Mech HSU and interface cable provides a superior tip-standoff sensing solution for your laser system.

Figure 1


2 Installation

2.1 Electrical Grounding and Noise

The capacitive sensing circuitry contained in the HSU measures minute changes in electrical capacitance between the tip and earth-ground to determine tip-to-part standoff distance. In order for this circuit to function properly, the part and the cutting head need to be connected to a good earth ground.

Ideally the ground should be established from a ground rod, approximately 2 meters in length driven into the ground located near the base of the machine.

A large gauge (14AWG, 1.6mm diameter or larger) ground wire should be run from the ground rod to the part. A separate wire should also be run from the ground rod to the mount of the cutting head.

Electrical noise can create sensing issues. Large electric motors, arc welders and other devices may be a source of significant electrical noise. In order to eliminate this noise it may be necessary to connect a ground wire to the chassis of any such device in proximity of the process.

2.2 Interface Box Mounting

The interface box mount pattern is illustrated in Figure 2. Important things to consider when mounting the interface box:

Standard cable length is 15 meters (50 feet).

Easy access for maintenance.

Mounting such that debris from the process is not directed at the interface box.

Mounting in an area where there are no water leaks or oils from hydraulic presses.

Figure 2


2.3 Connections

The Basic+ HSU Interface has four user connections. See Figure 3.

2.3.1 TB1 – Supplied Power

TB1 is a 3-position terminal block for supplying power and earth-ground.

2.3.2 TB2 – Laser System Interface

TB2 is a 12 position terminal block used for the laser system interface. On this terminal block there are three optically isolated outputs, one optically isolated input, one analog input, and two analog outputs. A detailed description of these signals can be found in Section 3.

2.3.3 Micro USB Connector

The USB port provides the interface connection between the HSU and a computer. Laser Mechanisms provides PC software called Basic+ HSU Utility that allows monitoring of the HSU and changing the HSU settings.

2.3.4 HSU Interface Cable

The main interface cable between the HSU and the Basic+ Interface connects to the Basic+ Interface with a 14-pin circular connector. This cable carries power for the HSU, analog standoff signals, digital I/O and serial communications to the HSU.

Figure 3

See Section 6 – Interface Specifications for a description of all connections.


3 Basic+ HSU Interface Signals

3.1 VHSU Standoff (Analog Out)

The VHSU analog output is proportional to the distance between the sensor and the target material. See Figure 4.

Positive progressing voltages indicate the sensor is moving further from the target material.

Negative progressing voltages indicate the sensor is moving closer to the target material.

There are two operating curve outputs; Linear or Optimized.

The Linear output is scaled at approximately 1V/mm (e.g. 1mm=1V, 2mm=2V).

The Optimized output has varying slopes; as the material gets closer to an object, the slope is greater. Please refer to Section 4.4 for the output setting and curve selection method.

Example of Linear Feedback Curve Figure 4

Most digital servo amplifiers with a software interface can be considered Intelligent. They will use a variety of methods for generating the Error Detection stage of the servo loop. In this mode of operation, the analog output from VHSU should be connected to the motion controller’s analog input. See Figure 5.

Figure 5

In order to achieve a maintained distance between the sensor and the target material, a reference must be set. The motion control system must be configured to accept an offset value relating to the desired analog sensor value.

3.2 VREF (Analog Input)

The Vref input is part of the equation used to generate the Vdif output. The Vref input establishes a target voltage level for a closed servo loop system (i.e. a 1V input for a 1mm standoff).

3.3 VDIF (Analog Output)

The VDIF output can be used as a servo command signal when connected to the servo drive. The Gain factor can be set using Basic+ HSU Utility and has a range of +/-50.

VDIF = (VREF - VHSU) x Gain

3.4 Ready (Digital Output)

When active, this output indicates that the system is operating normally. The absence of this signal indicates a problem with the system. It should be tied in conjunction with the motion inhibit function of the motion controller. If no Ready signal is present

Verify that the sensor is calibrated

Check the cabling

Verify that the head is not too hot.

This output must be monitored and action taken upon each instance of this condition.

A fault in the Ground integrity of the HSU will also cause the Ready signal to deactivate.

3.5 Touch (Digital Output)

When active, this output indicates that the sensor tip has come into contact with an object. This may be the target material, process debris or an obstruction. All of these conditions are not necessarily faults. This output must be monitored and action taken under conditions where Touch is active for a period of time.


3.6 Status (Digital Output)

The Status output is a handshake for the calibration input (CAL). When the sensor is requested to calibrate, this signal will become active. Upon completion of the calibration, this signal will deactivate (takes less than 0.5 seconds).

If the sense circuit to the tip is shorted, Status will not become active after the request for calibration.

If the sense circuit is open, Status will remain active for 1-2 seconds after the request for calibration.

3.7 Calibrate (Digital Input)

The Calibrate input is a request for sensor calibration. The calibration should take place with the tip about 12mm away from a grounded metallic surface at least 100mm in diameter. The calibration must be performed at power up and preferably every cycle.

Note: It is recommended the tip be calibrated every time the head is in a retracted position. The calibration procedure takes ~150ms and will ensure proper tip standoff is maintained.

Calibrating at a standoff greater than 12mm distances will result in standoff readings that are slightly less than the optimum level.

Calibrating at a standoff less than 12 mm will result in standoff readings that are slightly more than the optimum level.

The height sense electronics are designed to operate with dynamic stability control of the nozzle standoff with varying environmental conditions, such as temperature, humidity and cutting debris deposits. The dynamic control is achieved by resetting the calibration as frequently as possible so the head is reset before any significant change in any of the environmental conditions can occur. This method of control provides much better control than methods which try to passively stabilize the standoff.

It is very important to give the head a recalibrate pulse more often than environmental changes occur. This will vary with each process and machine. In general doing it every time the head is moved away from the part is the best procedure. If the head has been in a retracted position for an extended period of time the calibrate pulse should be resent before the head is brought to the work piece. If for some reason this is not possible due to very long cuts, or highly reflective materials, it may be necessary to add some basic passive stabilization to the system such as available air or water cooling to the tip assembly or head.


4 Basic+ HSU Utility

4.1 Introduction

Basic+ HSU Utility is PC software that provides a user interface for the Basic+ HSU via a USB connection. It allows the user to view temperature, voltage and status information as well as set parameters that change the characteristics of the output voltage. If it is needed, you can download the latest version of the software from the following URL:

http://www.lasermech.com/hsuupdates.asp

Note: You MUST configure a new HSU. The first time you power up your HSU and Basic + interface you must choose:

Nozzle type or tip retainer assembly (TRA) to be used

Output curve to be used

The remainder of Section 4 describes how to configure the HSU and Basic + interface.

4.2 Connecting

Connect the USB cable to your PC. If this is your first time connecting the cable, you will need to wait for the drivers to be installed. Once you get the message that the device is ready to use, you can launch Basic+ HSU Utility. See Figure 6. If your computer is unable to locate a driver, you can download the latest version from the following URL:

http://www.ftdichip.com/Drivers/VCP.htm

To connect to a Basic+ HSU, select the COM port of the USB cable from the drop-down list. The cable will generally take the highest numbered port in the list at the time it is first connected. You can also consult the Device Manager to determine the port number of the cable, which will appear as “USB Serial Port”.

Connection Window

Figure 6

http://www.lasermech.com/hsuupdates.asp

http://www.ftdichip.com/Drivers/VCP.htm


4.3 HSU Panel

The HSU Panel provides an interface to functions performed by the unit located on the laser head. See Figure 7.

The left side of the screen displays the available temperature sensors. Each meter displays the upper and lower limits in small digits, as well as a colored scale representing the current value relative to the limits. This scale shifts from green to yellow to red as the upper limit is approached. If the current value is above the upper limit, the sensor name is displayed in red and the scale is filled with red.

The center section displays Fault, Status, Touch and Ready indicators. Individual fault conditions are displayed to make it easy to diagnose problems.

The right side displays a representation of the selected Tip Retainer Assembly (TRA) along with the current Standoff voltage. If the displayed TRA does not match the TRA found on your head, the HSU may not function properly. See section 4.5.1 for information on changing the selected TRA.

HSU Panel

Figure 7

4.4 Settings

See Figure 8. Clicking the small arrow in the lower right corner of the HSU Panel will display the Settings Panel. Each setting can be adjusted by clicking in the box with the value you would like to change. A separate dialog box will then appear in which you can enter the new value.

HSU Settings Panel

Figure 8


4.4.1 Active Curve

See Figure 9. Clicking on the Active Curve number will open the Curve Selection Window. This window displays graphical representations of the curves available for the selected TRA at default Offset and Gain settings. Curves can be cycled through by clicking the left and right arrow buttons on the screen.

Each TRA style features pairs of standoff curve fit variations (linear and optimized) to meet the customer requirements. Some TRA styles also offer alternatives to the standard linear and optimized curves.

Curve Selection Window

Figure 9

4.4.2 Offset

The Offset setting will decrease the VHSU signal by approximately the amount specified. As a result the VDIF signal will also be affected. Typically this number is set at 0 so that 0.0mm standoff produces 0V.

4.4.3 Averaging Sample

When the HSU measures the capacitance between the tip and the work-piece, it will average this number of sampled readings. Increasing this number will have a smoothing effect on the HSU signals but it will also slow the response time down. Typically this number is set at 5.

4.4.4 Gain

The Gain is an integer between 1 and 10. It is a direct multiplier for the VHSU signal. For example, with Gain = 2 the VHSU signal will be approximately 2V/mm instead of the 1V/mm on a linear scale. Typically this number is set at 1.


4.5 Basic+ Panel

The Basic+ Panel can be accessed by clicking the HSU/Basic+ toggle button in the upper right corner of the window. See Figure 10. Here, you will find functions that are handled by the Basic+ Interface box.

Basic+ Panel

Figure 10

On the left side is the Ground Voltage check. This meter is used to verify that the voltage reading at ground is close to zero. The upper limit can also be specified by clicking the Set Limit button.

The center section allows the gain used with VDIF to be viewed and adjusted.

Finally, the Set TRA button allows you to change the selected TRA.

Please note that all Basic+ Interfaces are shipped with no specific TRA setting. You MUST choose a TRA setting the first time you power up the HSU. Once the TRA is set, you will only need to change the setting if a different TRA is used.

4.5.1 TRA Selection

The TRA Selection Window includes a library of tip assemblies that the Universal HSU has been designed to work with. See Figure 11. The libraries correspond to the four most common product lines.

TRA Selection Window

Figure 11

Navigate through the tabs to locate the picture and part number that matches your TRA. If you are unable to find your exact model, please contact Laser Mechanisms for assistance in selecting a suitable substitute. After selecting a new TRA, it is important to select an active curve that is designed for that TRA. See section 4.4.1 for information on selecting the active curve.


4.6 Advanced Menu

The Advanced menu allows you to upload new curve data to your HSU.

Click on the advanced menu and choose Load Curve. Then, choose the appropriate height sense curve file (.hsc extension) in the pop up screen that appears. See Figure 12.

Curve Selection Pop-up Screen

Figure 12

It will take several minutes to transfer the new curve data to the HSU.

The curve data is stored in the HSU’s non-volatile memory, so the curve data only needs to be loaded once.

Do not disconnect during the curve data transfer. The data may become corrupted.

When the curve data is transferred a pop-up screen will appear that says “Curve Successfully Loaded.” Click OK.

After the curve data is transferred to the HSU, select the appropriate curve according to Section 4.4.


5 Example of Integrating the HSU to a PLC/CNC

In general, the HSU is intended to be very simple in design. The integration into a motion system requires a minimal amount of hardware wiring and I/O resources. This section provides examples on how to integrate the HSU into a PLC/CNC based motion system using Ladder Logic. However, these examples are not meant to be exact, as your actual system will have different labeling and assignments. The integrator is encouraged to build off of these examples and modify them to best meet the design criteria for the system.

There are significant advantages of having the following logic signals generated within the PLC/CNC rather than on the height sensor electronics or external circuitry. These advantages include:

The user can adjust all of these parameters through the PLC/CNC.

The safety interlocks for the PLC/CNC are retained because direct servo control is not given to the HSU.

There is less opportunity for electrical noise to cause interference because the signals are generated within the code of the PLC/CNC.

The system integrator builds the controls directly into their own system, which gives the operator one point of control.

5.1 In-Position

Typically the In-Position signal is generated by comparing the actual standoff to the desired standoff. Rung 1 gives an example of how to generate the In-Position signal. See Figure 13.

Figure 13

5.2 Run/Hold

There are a couple of different ways of implementing a Run/Hold request. The first example is to simply have the Hold request tied directly to the drive-enabled contact as shown in Rung 2. Other conditions for a hold should also be applied in-series to Hold in this rung. See Figure 14.

Figure 14

The second example is to set the drive command to a constant value of zero (K0) as shown in Rung 3. See Figure 15. Be careful not to set the drive command value in another rung as it might cancel out the effects of this one. (Notice that Rungs 4 and 5 both require that Hold is not active).

Figure 15


5.3 Calculating the Standoff Error

A simple calculation can be used to generate a standoff error signal that is assigned to the Drive Command. See Figure 16. This allows the Z-axis to track the surface of the part and maintain a constant standoff value. Rung 4 takes the Sense voltage, subtracts the desired standoff value (V1401) and multiplies the result by a Gain value (V1402). The final result is assigned to the Drive Command.

Figure 16

5.4 Setting the Drive Command on Tip-Touch

In some instances it may be desirable to have the Drive Command revert to constant value when Tip-Touch is active to move the Z-axis away from the part. See Figure 17. In the example shown in Rung 5, the value V1403 will be sent to the Drive Command V1400. Typically setting the Drive Command to 10V will move the Z-axis up.

Figure 17


6 Interface Specifications

Example of Sourcing Outputs Example of Sinking Outputs

From Motion Controller and From HSU from Motion Controller and From HSU

Figure 18

TB1

1 +24VDC

(18 to 30VDC) Power input (100mA)

2 0VDC Ground for all supplies (system common)

3 FGND Chassis connection for Earth Ground


TB2

1 VDIF Analog Output This is the difference between the reference voltage and HSU

voltage times a specified gain value. (Range +/-12V, <3mA)

2 GND Ground for all supplies (system common)

3 VREF Analog Input Reference voltage input (Range +/-10V, <1mA)

Used in calculating VDIF.


5 VHSU

(Standoff) Analog Output

This is a linearized or optimized voltage representing the measured tip-to-part standoff distance in millimeters. (<3mA) Voltage range: -10 to 10V. This signal will become -10V when a fault occurs with the HSU. (1mm=1V, or optimized response) Normal output range: 0 to 10V


7 CAL +

Digital Input

Customer supplied 18 to 30VDC. The CAL input is a request for

sensor calibration. The calibration should take place with the tip

about 12mm away from a grounded metallic surface at least

100mm in diameter. The calibration must be performed at power-

up and preferably every cycle.

When used with “sourcing” output signal, connect:

CAL – to Ground and;

CAL + to Output (18 to 30VDC)

When used with “sinking” output signal, connect:

CAL + to Power (18 to 30VDC) and;

CAL – to Output signal

8 CAL -

9 Output

Common

Connect to customer-supplied GND for sinking outputs or

connect to customer-supplied 5-30VDC sourcing outputs.


TB2 CONTINUED

10 READY Digital Output

When active, this output indicates that the system is operating

normally. The absence of this signal indicates a problem with the

system and should be tied in conjunction with the motion inhibit

function of the controlled device. The Ready output signal will

turn off when the ground voltage is above the set limit. However,

the Ready indicator light will remain on as long as the Ready

status from the HSU is active. (<100mA)

11 TOUCH Digital Output

When active, this output indicates that the sensor tip has come

into contact with an object. This may be the target material,

process debris or an obstruction. (<100mA)

12 STATUS Digital Output

The Status output is a handshake for the calibration input (CAL).

When the sensor is requested to calibrate, this signal will become

active. Upon completion of the calibration, this signal will

deactivate. If the sense circuit to the tip is shorted, Status will not

become active after the request for calibration. If the sense circuit

is open, Status will remain active for 1-2 seconds after the

request for calibration. (<100mA)

LED STATUS INDICATORS

1 POWER Power is being applied to the Basic+ Interface.

2 CAL The CAL input is active.

3 READY The READY signal from the HSU is active.*

4 TOUCH The TOUCH signal from the HSU is active.

5 STATUS The STATUS signal from the HSU is active.

6 HSU ON The Basic+ Interface has turned power on to the HSU. Power to

the HSU is turned off if the HSU is disconnected.

7 GND OK

The ground voltage is at an appropriate level.* The Ready output

signal will be turned off when the ground voltage is above the set

limit.

*The READY and GND OK indicators will flash when the HSU is disconnected from the Basic+ Interface.


RESET BUTTON

Momentarily interrupts power being supplied to the Basic+ Interface and HSU. The HSU will recalibrate on

power-up.

Standoff Distance Range (1 mm Recommended) .......................................................... 0.2 mm to 8.0 mm

Calibration .......................................................................................................................... Auto Calibrating

Response Time ............................................................................................................................. <1 msec.

Temperature Stability ......................................................................... ±5% of Standoff Setting, 0° to 45° C

Power Requirement ....................................................................................................................... +24VDC

Output (Optimized Curve for Flat Metal or Linear Signal) ...................................... ±10 V or 0-10 V Analog

Specifications are subject to change without notice.


7 Troubleshooting

This height sensing unit is designed for robustness and simplicity with very little adjustment. Most height sensing problems can be attributed to electrical shorts between the tip and the body of the cutting head, or poor connections to the tip. Basic+ HSU Utility also provides helpful diagnostic information to identify faults.

SYMPTOM CAUSE REMEDY

No signal present on VHSU Output

No Power Check to make sure that the proper power is applied to TB1.

Tip Shorted The tip must be fully insulated from ground and the body of the cutting head. Replace the white sense cable and/or the nozzle assembly. Check for debris that may be causing a short.

VHSU Output Signal Shorted or Open Inspect the wiring from TB2.

VHSU Output not indicating proper standoff

Wrong curve is selected There are multiple different feedback curves that the height sensor can produce. The default curve is a linear output. If the tip is approximately 12mm above a flat sheet at power-up, it will calibrate the tip to produce a 1V/mm output signal. The curve can be changed using Basic+ HSU Utility.

Calibration occurs automatically at power-up or after pressing the Reset button. Subsequent calibrations should occur often (every cut or cycle) to insure consistency.

If the VHSU output signal is slightly off, some correction can be made by adjusting the standoff height when the calibration occurs. A standoff of less than 12mm will cause the voltage of the VHSU output signal to be higher. Conversely, a standoff of more than 12mm will cause the voltage of the VHSU output signal to be lower.

Calibration not occurring at proper standoff height

Geometry of tip or part has been altered


VHSU Output is not stable, or noisy

Power supply to height sensor is noisy

Use a well-regulated DC power supply to provide proper voltage and current to height sensor unit.

External source of noise is causing electrical interference

External sources of electrical or radio frequency noise can interfere with the operation of the head. Move the control electronics away from motors and motor drives. Make sure the routing of the control cable is separate from wires that contain high voltages or high current.

Part or cutting head is not grounded or a ground loop is present

Poor grounds or poor grounding schemes can cause significant noise issues. In many cases a separate copper grounding rod needs to be inserted into the ground at a location close to the machine. From this grounding point insure that the cutting head and the part are grounded. Also make sure that any equipment is adequately grounded.

Status Signal remains on after calibration for more than 1 second and Basic+ HSU Utility indicates Cal Fault Short

Broken or disconnected sensing cable or nozzle

This can be an indication that the white sense cable is broken or there is a problem with the nozzle assembly. Replace the suspected components.

Status Signal remains off after calibration and Basic+ HSU Utility indicates Cal Fault Open

The sensing cable or the nozzle assembly is shorted

This can be an indication that the white sense cable is shorted or there is a problem with the nozzle assembly. Check the nozzle assembly for debris. Replace the suspected components.

Ready Signal remains off and Basic+ HSU Utility indicates Overtemp or Excessive Temperature Difference (<<)

Temperature fault Inspect all optics, including fiber (if applicable).

If system is otherwise functioning normally but ambient temperature is high, increase the temperature limits using Basic+ HSU Utility.

Ready Signal remains off and Basic+ HSU Utility indicates Cable Break

Sense cable broke after calibration Inspect sense cable and tip retaining assembly (nozzle). Bad connections or intermittent connections usually cause this fault condition. Recalibrate to clear fault.

SYMPTOM CAUSE REMEDY


8 Appendix A – Replacement of Basic Interface with Basic+ Interface

The Basic+ HSU Interface signals are back compatible with the previous Basic HSU Interface. The one exception is that the Basic+ Interface does not have + and – 12VDC power supply outputs. The chart below shows the common connections for both HSU’s.

Power Input

Basic Interface (TB2) Basic+ Interface (TB1) Pin Function Description

1 1 +24VDC Power input (300ma)

2 2 0VDC System Common

3 3 FGND Chassis connection

Interface

Basic Interface (TB1) Basic+ Interface (TB2) Pin Function I/O Type

N/A 1 VDIF Analog Output

N/A 2 GND

N/A 3 VREF Analog Input

N/A 4 GND

4 5 VHSU (Standoff) Analog Output

3 6 GND

6 7 CAL + Digital Input

5 8 CAL -

7 9 Output Common

8 10 READY Digital Output

10 11 TOUCH Digital Output

9 12 STATUS Digital Output


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Laser Mechanisms, Inc.

25325 Regency Drive • Novi, Michigan 48375 USA Phone: (248) 474-9480 • Fax: (248) 474-9277

In Europe: Phone: +32(0)92 18 70 70 • Fax: +32(0)92 18 70 79 Web: www.lasermech.com • E-Mail: [email protected]

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