Banner L-GAGE LT3 User Manual

L-GAGE® LT3 Long-Range Time-of-Flight Laser Sensor

Self-contained laser distance sensor, two discrete outputs

Features

•Extremely long range: 5 m with white targets, or 3 m with gray targets for diffuse mode sensors, up to 50 m for retroreflective models

•Two discrete (switched) outputs in each sensor, with independent window limits†

•Discrete outputs can be used for precision background suppression

•Output select wire is used to choose either NPN or PNP outputs (see hookups)

•Fast, easy-to-use integrated push-button TEACH-mode programming; no potentiometer adjustments

•Remote TEACH function for security and convenience

•Output response is programmable for three speeds

•High-grade retroreflective target included with each retroreflective-mode sensor

•Choose 2 m or 9 m unterminated cable, or 8-pin Euro-style swivel QD connector

•Rugged construction withstands demanding sensing environments; rated IEC IP67, NEMA 6

! WARNING . . .

Not To Be Used for Personnel Protection

Never use these products as sensing devices for personnel protection. Doing so could lead to serious injury or death.

These sensors do NOT include the self-checking redundant circuitry necessary to allow their use in personnel safety applications. A sensor failure

or malfunction can cause either an energized or de-energized sensor output condition. Consult your current Banner Safety Products catalog for safety products which meet OSHA, ANSI and IEC standards for personnel protection.

Models

	Models	Sensing	Laser	Sensing	Cable*	Supply	Discrete
		Mode	Class	Distance		Voltage	Output
	LT3BD				2 m (6.5')
				0.3 to 5 m	8-wire
		Diffuse	Class 2
	LT3BDQ			(11.8" to 16.4')	8-pin		NPN or
					Euro-style QD	12 to
							PNP
					2 m (6.5')	24V dc
	LT3BDLV						Selectable
		Retro-		0.5 to 50 m**	8-wire
			Class 1
	LT3BDLVQ	reflective		(20" to 164')	8-pin
					Euro-style QD

*9 m cables are available by adding suffix “W/30” to the model number of any cabled sensor (e.g., LT3BD W/30). A model with a QD connector requires a mating cable; see page 11.

**Retroreflective range specified using included model BRT-TVHG-8X10P high-grade target.

!sensor contains no userserviceable components.

Do not attempt to repair.CAUTION . . . This

Incorrect component values may produce hazardous laser radiation levels.

†NOTE: See Banner website for information on analog/discrete models at: bannerengineering.com

Printed in USA

02/05

P/N 68503 rev. C

L-GAGE® LT3 Long-Range Time-of-Flight Sensor – Two Discrete Outputs

Theory of Operation

A short electrical pulse drives a semiconductor laser diode to emit a pulse of light. The emitted light is collimated through a lens, which produces a very narrow laser beam. The laser beam bounces off the target, scattering some of its light through the sensor’s receiving lens to a photodiode, which creates an electrical pulse. The time interval between the two electrical pulses (transmitting and receiving the beam) is used to calculate the distance to the target, using the speed of light as a constant.

Multiple pulses are evaluated by the sensor’s microprocessor, which calculates the appropriate position value. The discrete (switched) output energizes whenever the target is located between the user-programmed discrete window limits. Window limits for both discrete outputs may be the same, or they may be programmed independently.

User
Interface
		Laser	Lenses	Target
	Emitter	Emitter
		E
	Circuitry
Microprocessor	Analog
Time-of-Flight		R
	Signal
Engine
	Processing	Receiver
		Element
Output
Circuitry

Figure 1. Theory of operation

Programming

Response Speed

Prior to setting window limits, use the sensor’s Speed push button to toggle between the three response speed settings. The selected speed will be indicated by one of the three Response Speed indicator LEDs (see Figure 2). See Specifications for further information.

Sensor Setup

Allow 30 minutes after power-up to allow the sensor’s internal temperature to stabilize, before operating or attempting to program the sensor. If the sensor will be used in applications where the temperature is several degrees higher or lower than ambient, allow the sensor to stabilize in that condition before programming the window limits. (Range will decrease as the sensor warms up.)

The laser enable feature allows the sensor to be continually powered, and enabled only when being used. This eliminates the need for the extended warm-up period between uses.

The sensor’s red Signal LED indicates the condition of the received signal from the object being measured. When programming window limits, this LED must be ON solid (not flashing) for the sensor to accept the setting. On diffuse-mode models, to ensure that the received signal will not be marginal during operation, move the target object 300 mm beyond the furthest desired set point during setup, and verify that the signal LED is still ON solid.

Window Limits

Window limits may be taught to the sensor in several ways. The following methods

(beginning on page 4) describe the programming procedures using the push buttons on the top of the sensor or via remote programming (remote TEACH).

Signal LED

SIGNAL OUTPUT

Output LED

FAST

Response Speed

Response Speed

SPEED

Indicators

MED

Push Button

SLOW

Discrete Output 1

TEACH

Discrete Output 2

Teach LED

Teach LED

Discrete Output 1

D

D

Discrete Output 2

Programming

POWER

Programming

Push Button

Push Button

Power ON/OFF LED

Figure 2. Sensor features

Banner Engineering Corp. • Minneapolis, MN U.S.A.

2	P/N 68503 rev. C	www.bannerengineering.com • Tel: [phone]

L-GAGE® LT3 Long-Range Time-of-Flight Sensor – Two Discrete Outputs

Class 2 Safety Notes

Low-power lasers are by definition incapable of causing eye injury within the duration of the blink, or aversion response, of 0.25 seconds. They must also emit only visible wavelengths (400700 nm). Therefore, an eye hazard can exist only if an individual overcomes the natural aversion to bright light and stares directly into the laser beam. These lasers are required to have a “hazard” label and to have an indicator light to indicate that laser emission is occurring.

When operating a class 2 laser:

•Do not permit a person to stare directly into the beam

•Do not point the laser at a person’s eye at close range

Beam Paths:

The beam emitted by a class 2 laser product should be terminated at the end of its useful path. Open laser beam paths should be located above or below eye level, where practical.

LASER LIGHT

NOT STARE INTO BEAM

CLASS 2 LASER PRODUCT

Avoid exposure - laser light emitted from this aperture

RADIANT POWER 0.5 mW 650 - 670 nm

COMPLIES WITH 21 CFR PART 1040.10 AND EN60825-1:1994

Push-Button Programming

Both outputs may be taught simultaneously, when complementary operation is required (while one output is conducting, the other is not). When taught separately, each output may be taught different limits (one output may be taught a window, and the other may be programmed for background suppression, for example).

Remote Programming

To program the sensor remotely or to disable the keypad, the Remote Programming function may be used. Disabling the keypad prevents accidental or unauthorized adjustment of any programming settings. Connect the yellow wire of the sensor to +5 to 24V dc, with a remote programming switch connected between them.

NOTE: The impedance of the remote teach input is 55 kΩ.

Programming is accomplished by following a sequence of input pulses (see pages 4 and 5). The duration of each pulse (corresponding to a push button “click”), and the period between multiple pulses, are defined as “T”: 0.04 seconds < T < 0.8 seconds.

Teaching Discrete Limits for Background Suppresson

For some applications, ignoring objects beyond a certain distance may be required. To suppress the background, place a target object at the selected distance, and teach the position twice. The sensor’s discrete output will activate when an object is detected between the sensor’s minimum sensing distance and the taught position.

NOTE: The sensor allows for some forgiveness in this procedure. If the two limits are not exactly the same (but less than 20 mm apart), the sensor will put the set point at the “average” of the two limits.

Output 1 and Output 2 may be taught independent limits for background suppression (see Figure 3).

To set both outputs at exactly the same limits, set them simultaneously. This will result in complementary outputs (while one output is conducting, the other is not; see Figure 4). Hysteresis will be controlled by Output 1 and Output 2 will follow.

Output 1
Output 2			Teach
			Point 1
Near		Teach			Far
		Point 2
Sensing					Sensing
Range					Range

Figure 3. Each output has its own limit for background suppression

Output 1
Output 2
				Far
Near		Teach
Sensing		Point		Sensing
Range				Range

Figure 4. The two outputs share identical limits for background suppression, but are complementary

Banner Engineering Corp. • Minneapolis, MN U.S.A.

www.bannerengineering.com • Tel: [phone]	P/N 68503 rev. C	3

L-GAGE® LT3 Long-Range Time-of-Flight Sensor – Two Discrete Outputs

Teaching Independent Limits for Either Output

Either output may be programmed first.
	Output 1
			Near			Far
			Limit 1			Limit 1
	Output 2
		Near			Far
		Limit 2			Limit 2

Figure 5. Each output has its own near and far limits

Mode

Programming

First Limit

Teach

Teach	Second Limit
Program Second	Output

Push Button

0.04 sec. ≤ “click” ≤ 0.8 sec.

Procedure

Result

• Push and hold

• Appropriate TEACH LED

push button for

turns ON

desired output

• Sensor is waiting for first

> 2 seconds*

limit

or

D

D

• Position the target for

• TEACH LED flashes

the first limit**

• Sensor learns first limit

• “Click” the same push

and waits for second limit

button

D

D

• Position the target for

• TEACH LED goes OFF

the second limit

• Sensor learns second

• “Click” the same push

limit and returns

button

automatically to RUN

mode

D

D

Repeat for other output, if a second output is desired.

	Remote Wire
	0.04 sec. ≤ T ≤ 0.8 sec.
Procedure	Result

No action required

• Position the target for the first			• Appropriate TEACH LED turns
limit**			ON, then flashes at 2 Hz
			• Sensor learns first limit and
Output 1		Output 2
			waits for second limit
• Single-pulse		• Double-pulse
the remote		the remote line
line
T		T T T
• Position the target for the second			• Appropriate TEACH LED
limit			goes OFF
• Single-pulse the remote line			• Sensor learns second limit
			and returns automatically to
	T		RUN mode

*Sensor will return to RUN mode if first TEACH condition is not registered within 120 seconds.

**Press and hold the same push button (or hold the remote line high) > 2 seconds (before teaching the second limit) to exit PROGRAM mode without saving any changes. The sensor will revert to the last saved program.

Banner Engineering Corp. • Minneapolis, MN U.S.A.

4	P/N 68503 rev. C	www.bannerengineering.com • Tel: [phone]