Rockwell Automation 42DR Intrinsically Safe Sensor - Manual (Page 3)

3
Description
Type 42DR Series 5500 QD Intrinsically Safe miniature self-contained
Photoelectric controls each consist of a combination modulated LED light
source, high speed silicon photodetector and dual open collector sold state
outputs which can be used to interface with programmable controllers,
computers, digital control systems or E-M control relays via Intrinsic Safety
Zener Diode Barriers.
The Type 42DR Series 5500 controls are modular in design and consist of two
components—a plug in photohead and a power base which are selected to
suit your functional requirements and assembled together at the point of
installation. The photohead includes a unique Quick-Disconnect feature so that
it can be quickly mounted to or removed from the power base by simply turning
one screw, without disrupting control wiring or alignment. This capability reduces
production downtime and replacement cost and precludes the need for adding
plug and cable assemblies for field disconnect purposes.
Please note that the Series 5500 photoheads and the Series 5500 power base
are keyed so that no other photohead other than the Series 5500 can be
mounted to the Series 5500 power base in a hazardous location. The user
must disconnect the power before removing the quick-disconnect
photoheads or covers.
All Type 42DR Series 5500 (5700) Photoelectric controls must be used
with Intrinisic Safety Zener Diode Barriers.
Photoheads
There are four different photoheads available. For reflex operation (with
retroreflective target), use Type 42DRU Model 5500 which provides an
operating range from 1 to 30. For polarized reflex operation (with corner
cube type retroreflective target), use Type 42DRU Model 5700 which provides
an operating range from 6 to 15. For proximity operation (diffuse reflection
off the object itself), specify Type 42DRP Model 550 which offers an operating
range from 0 to 5. The design of Type 42DRA Model 5500 special function
photohead increases the application capabilities of the control line in difficult
environmental conditions by use of fiber optics and special lens assemblies.
In all models, the photohead contains all the functional electronics and optics. It
includes synchronous detection circuitry which tends to restrict the control to
operate only with its own pulsed LED source. Adjustable input sensitivity
broadens control application capability to those involving translucent and even
transparent materials, such as plastic films and glass. A switch is provided to
assure sensitivity adjustment over the entire control operating range.
With a flick of a switch, the Type 42DR control provides operation in either a
light energized (beam break) or dark energized (beam make) mode.
An optical shutter on the Type 42DRP proximity control permits the use of a
single control for both short- and long-range proximity applications. With the
shutter in the short range (SR) position, the maximum operating distance is 1.
The very sharp drop off in operating margin as shown in the Type 42DRP
response curve on page 6 helps to ignore backgrounds that are close to the
object being detected.
The dual open collector outputs, one an NPN open collector for current sink
and the other a PNP open collector to provide current source, are included in all
Type 42DR controls to maximize customer logic interconnection capabilities.
Therefore, these controls provide the opportunity for simultaneous connection to
relay loads or opto-coupler drives and TTL logic outputs. See page 7 for
connection diagrams.
Power Base
Type 42DRU, 42DRP, and 42DRA Intrinsically Safe models 5500 and 5700
Photoheads can be plugged only into a terminal base Type 42DTB Model
5500 suitable for voltage inputs of 13 to 29.5V DC.
The Type 42DTB Model 5500 Terminal Base allows the user to make his
incoming and outgoing connections directly to the control thereby eliminating the
need of a separate junction box. Wiring connections are made to easy-to-wire
pressure type terminals with nonrotating clamps on the screws capable of
handling up to two #14AWG wires.
Ordering Instructions
1. Select Power Base
Base Type Voltage Supply Type & Model
Terminal 13 to 29.5V DC 42DTB- 5500
2. Select Photohead
Operating Mode
Output
Characteristics Type & Model
Reflex
NPN (Current Sink)
and
PNP (Current Source)
42DRU- 5500
Polarized Reflex 42DRU- 5700
Proximity 42DRP- 5500
Fiber Optic
Wide Angle
Fixed Focus
42DRA- 5500
3. Select Mounting Assembly
#60--1785 Universal, general purpose, 360 adjustment.
#60--1748 Heavy Duty, for mechanical protection.
#60--2014 Flexi-Mount, for Unistrut mounting on conveyor rails.
#60--2083 Photoguard, #12 gauge cold rolled steel heavy duty protection.
4. Select Intrinsic Safety Zener Diode Barriers
Select Control Drawing on page 7 for wiring diagrams of sourcing and
sinking output configurations. Barrier selection is described below for
each Control Drawing configuration. For installations, to ensure safety
each Barrier must comply with the entity parameters indicated on the
Control Drawing.
In selecting the Intrinsic Safety Zener Diode Barriers, it is important to consider
the resistance of the barrier to ensure operational characteristics in the midst of
inherent barrier voltage drop.