OPBT2 - BANNER ENGINEERING

OMNI-BEAM™

The OMNI-BEAM™ model OSBFAC is a special-purpose ac-coupled

fiber optic sensor head module. It is intended for applications in which

the light signal change is so small that sensitivity adjustment of ordinary

dc-coupled sensors is difficult or impossible. The OSBFAC responds to

even smaller signal changes than do standard fiber optic OMNI-BEAM

sensors set for LOW hysteresis, and is less affected by gradual signal

changes due to dirt buildup, etc. Typical applications include thread

break detection, web flaw detection, and detection of small parts falling

randomly from vibratory feeders or small presses.

Many such low-contrast photoelectric sensing applications present prob-

lems to dc-coupled sensors because of switching hysteresis. Switching

hysteresis is a designed-in property of dc-coupled sensors that causes the

"turn-on" point of the sensor's dc-coupled amplifier to be slightly differ-

ent than the "turn-off" point. Its purpose is to prevent "indecision" and

erratic operation of the sensor's output circuit when the light signal is at

or near the switching point of the dc-coupled amplifier.

The OSBFAC, with its ac-coupled amplifier, reliably amplifies the small

signal changes found in many low-contrast sensing applications. An

automatic gain control (AGC) feedback system locks onto the light signal

and continually adjusts the light intensity of the emitter so that the system

is always maintained at exactly the desired reference level regardless of

the sensing range or degree of environmental contamination. A multi-

turn GAIN control enables setting of the amplifier sensitivity.

Instead of the D.A.T.A.™ array of other OSB Series sensor heads, the

OSBFAC has a LOCK indicator LED that lights when the AGC circuit

has locked onto the signal, and a LOAD indicator LED that lights

whenever the sensor's output circuit is energized. Both LEDs are easily

visible beneath the OSBFAC's transparent LEXAN® top cover.

A slide switch inside the base of the OSBFAC sensor head selects either

light- or dark-operate. When light operate is selected, output occurs on

a dark-to-light transition. When dark-operate is selected, output occurs

on a light-to-dark transition. The OSBFAC requires use of the model

OLM8 or OLM8M1 slide-in logic module. Sensor head output is in the

form of a quick pulse, and an OLM8 Series module is used to condition

this pulse to the desired length. See data sheet P/N 03522 or 03533 or the

Banner product catalog for further information on these logic modules.

The OSBFAC ac-coupled fiber optic sensor head may be used with any

of the following OMNI-BEAM power block models: OPBT2 and

OPBT2QD (powered by 10 to 30V dc); OPBA2 and OPBA2QD

Highly sensitive to very small signal changes

Automatic Gain Control circuit continually adjusts

emitter light output to maintain system gain

Ideal for low contrast applications such as web flaw

and thread break detection, falling parts detection

Selectable light-operate or dark-operate; no false

pulse on power-up

Use with standard OMNI-BEAM ac or dc power

blocks and model OLM8 logic module

Printed in USA P/N 03553D4B

Sensing modes and ranges*, model OSBFAC

WARNING This photoelectric pres-

ence sensor does NOT include the self-check-

ing redundant circuitry necessary to allow its

use in personnel safety applications. A sensor

failure or malfunction can result in either an

energized or a de-energized sensor output con-

dition.

Never use this product as a sensing device for personnel protection.

Its use as a safety device may create an unsafe condition which could

lead to serious injury or death.

Only MACHINE-GUARD and PERIMETER-GUARD Systems,

and other systems so designated, are designed to meet OSHA and

ANSI machine safety standards for point-of-operation guarding

devices. No other Banner sensors or controls are designed to meet

these standards, and they must NOT be used as sensing devices for

personnel protection.

•

Model OSBFAC

AC-coupled

Fiber Optic Sensor Head

(powered by 105 to 130V ac); or OPBB2 and OPBB2QD

(powered by 210 to 250V ac). Power blocks are available either

with standard 6-foot long attached PVC cable, or with an integral

male quick-disconnect (QD) connector (mating QD cable is pur-

chased separately). Information on power blocks and mating

quick-disconnect cables may be found in the Banner product

catalog.

Basic hookup information is given on page 2. Complete power

block hookup information may be found on the data sheet that

accompanies each power block, or in the Banner product catalog.

Model OSBFAC with power block and rectangular fiber

optics attached.

Opposed: 1/16-inch fibers, no lenses 3.5 inches

Opposed: 1/8-inch fibers, no lenses 7.0 inches

Opposed: 1/8-inch fibers, L9 lenses 5.3 feet

Opposed: 1/8-inch fibers, L16F lenses 17.8 feet

Diffuse: 1/8-inch fiber, no lens 0.6 inches**

Retro: 1/8-inch fiber, L9 lens, BRT-3 target 2.3 feet

*Minimum guaranteed ranges

**Distance to white test card

Specifications, model OSBFAC Sensor Head

The Bi-Modal™ output of OMNI-

BEAM dc power blocks is wired

for current sinking (NPN) opera-

tion (100mA max.) by connecting

the BROWN supply wire to +V dc,

and the BLUE wire to dc common.

The Bi-Modal™ output of OMNI-

BEAM dc power blocks is wired for

current sourcing (PNP) operation

(100mA, max.) by connecting the

BLUE supply wire to +V dc, and the

BROWN wire to dc common.

OSBFAC dc hookup (power blocks OPBT2 & OPBT2QD)* OSBFAC ac hookup (power blocks OPBA2, OPBA2QD,

OPBB2, and OPBB2QD)*

*Note that when standard OMNI-BEAM power blocks are used with the

OSBFAC, the power block ALARM output functions as a second output

that exactly follows the action of the main output. The capacity of this

second output is 100mA max. (for dc-powered power blocks) and 200mA

max. (for ac-powered power blocks). Also note that, when dc-powered

power blocks (OPBT2 and OPBT2QD) are used with the OSBFAC, they are

not short-circuit protected.

OMNI-BEAM ac power block

models OPBA2 and OPBA2QD are

for 105-130V ac power. Models

OPBB2 and OPBB2QD are for

210-250V ac power. The hookup

diagram (right) is the same for all

four models.

The LOAD output (500mA, maxi-

mum) is isolated. The ALARM

output is internally connected to ac

"hot", and exactly follows the ac-

tion of the LOAD output. The

ALARM output is capable of

switching up to 200mA, maximum.

Sensing Beam: infrared, 880nm

Sensing Range: see "box" on page 1

Response Time: 1 millisecond

Adjustments: GAIN control (15-turn clutched potentiometer) ad-

justs the sensitivity of the ac-coupled amplifier. Located on top of the

sensor beneath a transparent LEXAN® window.

Indicators: LOCK LED lights whenever the AGC system has

locked onto a signal. LOAD LED lights whenever the sensor's output

circuit is energized. Both indicators located on top of the sensor

beneath a transparent LEXAN® window.

Operating Temperature Range: -40 to +70°C (-40 to +158°F)

Construction: housing is molded from rugged VALOX® thermo-

plastic polyester for outstanding electrical and mechanical perfor-

mance in demanding applications. The top window is of transparent

LEXAN® polycarbonate. Hardware is stainless steel. When as-

sembled to a compatible power block module, all parts are fully

gasketed.

Dimensions, OSBFAC Sensor Head Module

with standard dc Power Block Module Attached*

Banner Engineering Corp. 9714 10th Ave. No., Minneapolis, MN 55441 Telephone 612/544-3164 FAX (applications) 612/544-3573

Installation and adjustment

OLM8

logic module (slide in)

Light/Dark

Operate

slide switch:

(slide left);

(slide right)

*Standard ac power block is .88" taller in height; overall height

of OSBFAC sensor head with an ac power block attached is 3.88".

1) The OSBFAC requires the use of an OLM8 Series slide-in logic

module. Refer to the data sheet packed with the logic module. Program

the OLM8's DIP switches for the required pulse type and duration range,

then slide the OLM8 into the slot in the sensor head. Set the OSBFAC

sensor head for either light- or dark-operate, using the slide switch on

the underside of the sensor head (see bottom photo, right).

2) Detach the clear LEXAN® top window from the OSBFAC by removing the single hold-down screw.

Assemble the OSBFAC head to the power block module using the four captive screws at the corners of the

module. Mount the sensor assembly at a convenient location (Banner mounting bracket model SMB30MM

is ideal for use with OMNI-BEAM sensors). Attach two individual glass fiber optic assemblies or one

bifurcated glass fiber optic assembly to the OSBFAC, following the instructions packed with the fibers.

Mount and align the sensing end(s) of the fiber(s), at the sensing location, in a position that will optimize

the differential between the "light" and "dark" conditions. Refer to the data sheet packed with the power

block in use. Connection of the load at this time is optional: the LOAD LED, shown in the photo (right),

will simulate the action of the load. Connect the power block to a compatible power source and apply power.

3) Present the "light" condition to the sensor*. Check to assure that the LOCK LED is "on". If necessary,

adjust the position of the fiber sensing tips so that the LOCK indicator reliably stays "on". While observing

the LOAD LED (and remembering the programmed pulse time, step #1), simulate the sensing situation by

presenting the sensing event to the sensor. If necessary, adjust the GAIN control (clockwise = increase;

counterclockwise = decrease) so that the LOAD LED changes state positively and reliably in response to

all desired variations of the sensing event. Note: Too much gain may result in response to unwanted

conditions (i.e. movement of fiber sensing ends due to vibration, etc.). While observing the LOAD

indicator, adjust the OLM8 timing exactly as desired. Connect the load to the sensor, and test the system.

*Note: If the "light" condition is a quick transition that cannot be simulated as a static condition, present

the "dark" condition in lieu of the "light" condition.