Ametek Gemco Brik 955QD Series Assembly instructions

Series 955QD
Gemco BrikTM with Qudrature Output
Linear Displacement Transducer
Installation, Programming and Maintenance Manual
The Brik
Series 955QD
A Linear Displacement Transducer

1080 North Crooks Road
Clawson, MI 48017-1097
Phone: [phone]
Fax: [phone]
www.ameteksensortech.com • www.ametek.com
Preface
This manual is divided into three parts. Part 1 provides the hardware overview for the 955QD Linear
Displacement Transducers (LDT). Part 2 provides instructions for installing the LDT’s to a mounting bracket.
Part 3 provides an overview and wiring instructions for the 955QD Quadrature Output LDT. To further assist
you, a glossary is provided at the back of the manual.
!Disconnect Power Before Servicing. The Gemco 955QD LDT Contains No
Serviceable Components. Consult Factory for Repair or Replacement.
Copyright 2001 by AMETEK Automation & Process Technologies
All Rights Reserved -- Made in the USA
Version 1.0
AMETEK Automation & Process Technologies has checked the accuaracy of this manual at the time it was
approved for printing. However, this manual may not provide all possible ways of installing and maintaining
the LDT. Any errors found in this manual or additional possibilities to the installation and maintenance of
the LDT will be added in subsequent editions. Any comments you may have for the improvement of this
manual are welcomed.
AMETEK reserves the right to revise and redistribute the entire contents or selected pages of this manual.
All rights to the contents of this manual are reserved by AMETEK. The Brik is a registered trademark
of AMETEK.

Contents
Chapter 1: Hardware Overview 1
1.1 Dimension Drawing for 955QD LDT ...............................................................2
Chapter 2: Installing the LDT 3
2.1 Installing the LDT ..........................................................................................3
Chapter 3: 955QD Overview 4
3.1 Quadrature Output ......................................................................................4
3.2 Signal Connection Application Note ...........................................................4-5
3.3 Quadrature Output Resolution and Speed .....................................................6
3.4 955QD Wiring Connection .......................................................................6-10
3.5 Features ................................................................................................11-13
3.7 Troubleshooting for 955QD ....................................................................14-15
3.8 Catalog Numbering System for 955QD ........................................................16
3.9 Specications for 955QD ............................................................................17
3.10 Accessories...............................................................................................18
Glossary 19
Installation, Programming and Maintenance Manual iii

Chapter 1: Hardware Overview
Chapter 1: Hardware Overview
The Series 955QD Brik with Quadrature Output is an accurate, auto-tuning, non-contact, linear displacement
transducer in an economical, low prole package. The transducer utilizes our eld proven magnetostrictive
technology to give absolute position, repeatable to .01% of the programmable sensing distance. The
streamlined anodized aluminum extrusion houses the sensing element and electronics. The magnet moves
over the sensing element that determines the position and converts it to incremental outputs.
The 955QD has a truly unique feature. The 955QD LDT has auto-tuning capability, the ability to sense
a magnet other than the standard slide magnet and adjust its signal strength accordingly. See chapter
3.5 (Features).
There is an indicator LED that is located at the connector end of the probe and provides visual status
information regarding the operation of the probe. Green indicates proper or normal operation. Red indicates
the loss of the magnetic signal or a probe failure. The LED ashes yellow/red or yellow/green when it is in the
AGC (Automatic Gain Control) mode. This is a special setup mode used to calibrate the probe for the magnetic
eld of the magnet in the oating magnet assembly or ring magnet of a cylinder. When the probe is in the
normal mode of operation, the LED with remain illuminated continuously.
Green: Magnet is present and within the active
programmed range.
Red: Fault, the LDT has lost its signal from the
magnet or the magnet has moved into the
Null or Dead zone.
Yellow: Used when setting ACG, yellow appears in short bursts combined with either red or green
when in the AGC mode
NOTE: The series number on your LDT is a record of all the specic characteristics that make up
your unit. This includes what interface type it is, its output signal and range, the type of
connector the unit uses, and stroke length. For a translation of the model number, see
Section 3.8: Catalog Numbering System.
The 955QD Brik with Quadrature Output is a linear displacement transducer. It provides an A quad B digital
output signal that is proportional to the position of the slide magnet assembly along the length of the probe.
The quadrature output makes it possible to have a direct interface to virtually any incremental encoder input
or counter card, eliminating costly absolute encoder converters and special PLC interface modules.
The 955QD Brik with Quadrature Output LDT can be ordered with 1 to 9999 cycles per inch of output
resolution. The transducer features an input to re-zero the probe “on the y”. Another unique feature is
the “Burst” mode; an input on the transducer triggers a data transfer of all the incremental position data
relative to the transducer’s absolute zero position. This is how incremental can provide absolute functionality.
The “Burst” input can be used to achieve absolute position updates when power is restored to the system or
anytime an update is needed to re-zero or home the machine without having to move the machine.
Installation, Programming and Maintenance Manual
1

Chapter 1: Hardware Overview
1.1: Dimension Drawing for 955QD LDT
Installation, Programming and Maintenance Manual 2
Figure 1-1: The Brik with Quadrature Output LDT
Drawing D0245400
.25
OF MAGNET SLUG


A standard female swivel mounting arm is
provided with the slide magnet assembly.
For extensions and other options contact
SpringFix at 810-795-3555 or
www.springlinkages.com
Mounting Brackets (SD0522000) slide in the
grooves on the side of the extruded housing.
When tightened down with fastening hard-
ware the mounting bracket clamps the unit
into place. It is recommended to use one
mounting bracket on each end and every
three feet between.
.22 MTG. HOLES
2 PER MTG. FOOT
.60
.30
R.87
360 ROTATION
1.00
.30
.36
1.97
1.372.68
1.50
.08
.28
.87 .56
.25 TO CENTERLINE MAGNET SENSOR
1.50
DEADZONE
STROKE
L = NULL + STROKE + DEAD ZONE
3.00 NULL
1.80
1.45 .82
.10
.22
10 PIN MALE
CONNECTOR
.98
.36
.40
.55
1.19
2.06
M5 X .40 DEEP
LINKAGE MTG. HOLE
M5 X .56 DEEP
ALTERNATE MTG.
HOLE FOR LINKAGE
P/N SD0521800
SLIDE MAGNET ASSEMBLY
.08
OF MAGNET SENSOR
.25 TO CENTERLINE
OF MAGNET
TO CENTERLINE
P/N SD0522100
FLOATING MAGNET ASSEMBLY
2 PLACES
360 ROTATION
R.87
2 PLACES
OTHER END
.359 C’BORE
.21 DEEP
1.50
.69
1.30
1.04
.68
.28
.87
1.37
.56
1.31
1.31
2.00
.75
.34
.50
1.00
.34
.20 THRU
.50
.25
.20 THRU

Chapter 2: Installing the LDT
Chapter 2: Installing the LDT
Mounting Instructions
The Series 955QD can be mounted vertically or horizontally using SD0522000 mounting brackets. The
mounting brackets slide in the grooves on the lower part of the extrusion and clamp down when tightened. It
is recommended to use one mounting bracket on each end and every three feet in between.
Ferro-magnetic material, (material readily magnetized) should be placed no closer than .25” from the sensing
surface of the LDT.
Mounting the Magnet Assembly
Before mounting the magnet assembly, you should consider the following:
• Ferromagnetic material should not be placed closer that 0.25” from the LDT’s sensing surface. Failure to
do so could cause erratic operation. Non-ferrous materials, such as brass, copper, aluminum, non-
magnetic stainless steel or plastics, can be in direct contact with the magnet assembly and sensing surface
without producing any adverse results.
• Minimal clearance between the LDT’s sensing surface and the magnet assembly through the full stroke
is required. Stress between the magnet and the rod can cause exing of the extrusion. This may appear
as non-linearity of the LDT’s output.
• When using the Floating Magnet assembly (SD0522100), the magnet should be installed within 3/8” of
the sensing surface. The magnet assembly should also be installed in such a manner that it remains an
even distance from the aluminum extrusion throughout the entire stroke. Improperly installed magnets
can result in output signal non-linearity.
Installation, Programming and Maintenance Manual
3

Installation, Programming and Maintenance Manual 4
Chapter 3: 955QD Overview
Chapter 3: 955QD Overview
A new method of interfacing magnetostrictive transducers offers customers an interface as common as analog
with the speed and accuracy of pulsed type signaling. The Gemco 955QD LDT provides quadrature output
directly from the transducer to the controller (see drawing below). The output from the transducer can be
wired directly to any incremental encoder input card, without the need for a special converter module or PLC
interface card designed specically for use with a pulse output magnetostrictive transducer.
3.1: Quadrature Output
The quadrature output provides absolute position data in engineering units. This means that the need for the
calibration constant (wire speed) programming has been removed, thereby eliminating the possibility of having
an improperly calibrated system. The output signal wires are driven by differential line drivers, similar to the
drivers used in most magnetostrictive pulse type transducers, providing a high degree of noise immunity.
A unique feature of this transducer is a “burst” mode of operation. An input on the transducer triggers a
data transfer of all the incremental position data relative to the transducer’s absolute zero position. This can
be used to achieve absolute position updates when power is restored to the system or anytime an update
is needed to re-zero or home the machine. Additionally, another input to the transducer can be used to
establish a “zero” position for the transducer.
3.2: Signal Connection Application Note
Overview
This application note will attempt to clarify the input and output signals of the 955QD quadrature probe.
Inputs
The quadrature probe has two inputs, the “zero” and “burst” inputs. These inputs are “single ended”. That
is, the connection for each input consists of only one wire, the corresponding signal wire. For these (single
ended) inputs, the signal is measured with reference to the power supply ground, which is sometimes referred
to as “common”.
The quadrature probe is available with either +24VDC level signal thresholds or TTL level thresholds. The
signal voltage level required to activate the input for the +24 VDC level signal is proportional to the power
supply voltage that the customer is supplying to the probe. This level is approximately 41% of the power
supply voltage. For example, if the power supply voltage powering the probe is exactly 24VDC, the threshold
voltage would be approximately 9.84 volts.

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual
5
The TTL level threshold signals are activated when these inputs exceed the typical TTL level threshold,
which is 2.0VDC.
Additionally, for the 24VDC level signals, the customer can specify either a “sourcing” or “sinking” type of
input. A “sourcing” input type is pulled high internal to the probe. To activate a “sourcing” input, the
customer must pull the signal lower than the threshold voltage to activate the input. A “sourcing” input
is usually driven by a “sinking” output or a switch connected to ground. A “sinking” input type is pulled
low internal to the probe. To activate a “sinking” input, the customer must pull the signal higher than the
threshold voltage to activate the input. A “sinking” input is usually driven by a “sourcing” output or a switch
connected to the power supply.
It is important that the customer drive the signal levels much greater or lower than the threshold voltages.
Asserting a signal with a voltage level close to the threshold voltage could induce multiple activations of that
input (or none at all) and therefore produce unexpected results or probe readings.
Outputs
The quadrature probe has three outputs, the “A”, “B” and “Z” outputs. These outputs are “differential” (also
known as “balanced”). That is, the connection for each output consists of two signal wires. These are typically
described as the “+” and “-” signals. For example, the “A” channel consists of “A+” and “A-”. The same
applies to the B and Z channels. For these (differential) outputs, the signal is measured with reference to
the other signal (i.e. the difference or differential). For example; if the “A+” signal voltage is greater than the
“A-” signal, channel “A” is a logic “1”. Conversely, if the “A+” signal voltage is lower than the “A-” signal,
channel “A” is a logic “0”. Again, this applies to the B and Z channels as well. Differential type signals
are much less prone to interference caused by electrical noise or ground loops more often found in single
ended signal connections.
The differential outputs of the A, B and Z channels are at RS-422 signal levels on option D (output drivers)
units. RS-422 is a well known TIA/EIA standard and common interface type for incremental encoders. The
RS-422 receiver channel (on the PLC or controller side of the connection) typically has what is referred to as a
termination resistor connected across the “+” and “-” signal pins. The value of the termination resistor is (by
RS-422 specications) typically 100 ohms. However, some receivers will work with greater resistance values
and some with no termination resistor at all. For proper signal integrity, especially at higher data rates (i.e.
quadrature pulse frequency), a termination resistor of no greater than 1Kohm is recommended.
Driving Single Ended Inputs
A differential output can also be used to drive single ended inputs. Special consideration must be given to
these types of applications. It should be noted the main signal requirements for an RS-422 signal is the
differential voltage of the “+” relative to the “-” signals and not necessarily the voltage level of any one of these
signals with respect to ground (or common). To meet the RS-422 specication, this differential voltage only
needs to be +/- 0.2 volts. However, an RS-422 driver will typically drive either the “+” or “-” signal to around
3.8 volts with respect to ground. This voltage is more than sufcient to drive TTL level inputs as well as
other low level inputs. The input voltage level specications of the PLC or controller being used should be
consulted for the actual level required.
When using PLS’s or controllers that are not TTL compatible output driver option “L” should be used.
Option “L” uses a 0L7272 line driver I.C. The output from this driver will be 1 volt less than the LDT’s
input power.
When physically connecting a differential output to a single ended input, only use the “+” signal, leaving
the “-” signal unconnected. Do NOT connect the “-” signals to ground. The “A+, “B+” and “Z+” signals
should be connected to their corresponding inputs. Insulate and tie back the “-” signals. See gure 3-5,
Single Ended Interface.

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual 6
3.3: Quadrature Output Resolution and Speed
The internal resolution of the 955QD Gemco LDT is 0.001”. This would be represented to the encoder input
device by specifying an output resolution of 1,000 cycles per inch for the transducer. Although the typical
resolution is 1,000 cycles per inch (CPI), the transducer can be ordered with virtually any CPI setting.
For a typical rotary type shaft encoder with incremental quadrature output, the output frequency of the
pulses is governed by the resolution of the encoder (pulses per turn) and the rotational speed (RPM) of the
encoder. The output pulses rate from the LDT transducer is xed and is controlled internally and can be
specied by the customer. The output frequency must be specied so that it does not exceed the maximum
pulse rate of the encoder input card the sensor is connected to. The output pulse frequency range can be
ordered from 10KHz to 1MHz.
3.4: 955QD Wiring Connections
Once the LDT has been installed, wiring connections can be made. There are two groups of connections you
will need to make. They are as follows:
• Power Supply Connections (including grounding and shielding)
• LDT Input/Output Connections
Power Supply/Ground Connections
The 955QD Brik standard cable is Alpha 6334, a multi-conductor cable. 10 conductors of 24ga, with an
aluminum/polyester/aluminum foil with drain wire plus an overall braid of tinned copper shield. Cable O.D.
is .270. To reduce electrical noise the shield must be properly used. Connect the cable’s shield to the
controller system GND. The cable shield is not connected at the transducer end. Always observe proper
grounding techniques such as single point grounding and isolating high voltage (i.e. 120/240 VAC) from low
voltage (10 - 30 VDC cables). Whenever possible, this cable should be run in conduit by itself.
UNIPOLAR
Figure 3-1: Power Supply Wiring
WARNING: Do not route the Brik with Quadrature Output cable near high voltage sources.
Single ended
powe supply
+10 to +30 VDC
+ COM
Pin 2 (red) Pin 1 (black)

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual
7
P/N: SD0527700
CONNECTOR PLUG - EXPLODED VIEW
18
72 9
3
45
6
10
10 PIN CONNECTOR
(AS VIEWED AT
SOLDER SIDE
4X SIZE
CABLE
WIRE COLOR
CONN.
PIN DESIG.
BLACK
RED
GREEN
BROWN
BLUE
ORANGE
YELLOW
WHITE
VIOLET
GRAY
1
2
3
4
5
6
7
8
9
10
Figure 3-2: Power Supply Wiring

Installation, Programming and Maintenance Manual 8
Series 955QD Wiring Diagram
Chapter 3: 955QD Overview
Figure 3-3: Wiring Diagram
Drawing E0238500
CABLE ASSY P/N SD0527700L*
* - LENGTH IN FEET
PIN - 1 BLACK
PIN - 10 GRAY
PIN - 9 VIOLET
PIN - 8 WHITE
PIN - 7 YELLOW
PIN - 6 ORANGE
PIN - 5 BLUE
PIN - 4 BROWN
PIN - 3 GREEN
PIN - 2 RED
COMMON
POWER +
B-
ZERO INPUT
BURST INPUT
B+
A-
A+
Z-
Z+
955QD LDT

Installation, Programming and Maintenance Manual
9
Chapter 3: 955QD Overview
Figure 3-4: Input Signal Connections for 955 Quadrature LDT
Drawing E0238400
ZERO
BURST
COMMON
BURST
ZERO
COMMON
VSOURCE
955QD
LDT
PIN-2
PIN-1 BLACK
RED +
PIN-8
PIN-9
WHITE
VIOLET
SUPPLY
10 TO 30V
POWER
-
P/N SD0527700LXX
CABLE ASSY.
955QD
LDT
PIN-8 WHITE
PIN-1 BLACK
PIN-9
10 TO 30V
SUPPLY
POWER
-
+
PIN-2
VIOLET
P/N SD0527700LXX
CABLE ASSY.
TYPICAL SINKING
OUTPUT INTERFACE
TYPICAL SOURCING
OUTPUT INTERFACE
INPUT CONNECTION FOR 955QD LDT WITH SOURCING INPUT
INPUT CONNECTION FOR 955QD LDT WITH SINKING INPUT
RED

Installation, Programming and Maintenance Manual 10
Chapter 3: 955QD Overview
Figure 3-5: Output Signal Connections for 955 Quadrature LDT
Drawing E0238300
TYPICAL SINGLE ENDED INTERFACE
BLACK
GREEN
BROWN
GRAY
ORANGE
YELLOW
BLUE
OUTPUT CONNECTION FOR A 955QD LDT WITH SINGLE ENDED INTERFACE
PIN-1
PIN-2 RED
PIN-3
PIN-4
PIN-10
PIN-6
PIN-7
PIN-5
N.C.
10 TO 30V
COMMON
VSOURCE SUPPLY
POWER
COMMON
B-
Z-
**
N.C.
**
A- N.C.
**
Z+
Note:
**
B+
A+
OUTPUT CONNECTION FOR 955QD LDT WITH DIFFERENTIAL INTERFACE
BLUE
YELLOW
ORANGE
GRAY
BROWN
GREEN
BLACKPIN-1
PIN-3
PIN-2 RED
PIN-4
PIN-10
PIN-7
PIN-6
PIN-5
10 TO 30V
COMMON COMMON
VSOURCE SUPPLY
POWER
Z+
Z-
Note:
*
Rt *
B-
B+
A-
Rt *
Rt
TYPICAL DIFFERENTIAL INTERFACE
A+
*
Rt is the termination resistor
typically used for RS-422 differential
connections. If these termination
resistors are not internal to the
controller, they should be installed
externally at the connector. If
these are not specified or included
with the controller, use 1K OHM
resistors.
Tie back and insulate unused
A-, B- and Z- wires.
CABLE ASSY.
P/N SD0527700LXX
CABLE ASSY.
P/N SD0527700LXX
955QD
LDT
955QD
LDT

Installation, Programming and Maintenance Manual11
Automatic Gain Control
The Automatic Gain Control feature is only used when sensing a magnet other than the standard SD0521800
slide magnet. If you are using the standard slide magnet, skip this operation.
When using the Floating Magnet assembly (SD0522100), the magnet should be installed within 3/8” of the
sensing surface. The magnet assembly should also be installed in such a manner that it remains an even
distance from the aluminum extrusion throughout the entire stroke. Improperly installed magnets can result
in output signal non-linearity.
To set the Automatic Gain Control (AGC) level for the probe follow these steps.
NOTE: Before starting, it is important to determine the input type of the LDT in question. On input type
“E” or “T”” take input pins 8 and 9 to pin 2 (Input Power). On input type “C” take input pins 8 and 9
to pin 1 (common).
1. Place magnet assembly close to the dead zone (but within the active region) of the probe.
NOTE: The north pole of the magnet should always be pointed towards the probe.
2. Power down the probe.
3. Short “BURST IN” (pin 8) and “ZERO INPUT” (Pin 9) to ground (Pin 1) for input type “C”
or to input power (pin 2) for input type “E” or “T”.
A. Apply power to the probe, the LED ashes Yellow and Red for one second
B. The LED will change from ashing yellow and red to ashing yellow and green once it has
found the magnet.
NOTE: If the LED never changes to ashing yellow and green; the magnet signal is too weak. Remove power
from the LDT and move the magnet closer.
NOTE: When the probe is in AGC mode, the output will be inactive.
The AGC is now complete.
To place the probe back into the normal operating mode follow these steps:
1. Power down the probe
2. Remove “BURST IN” pin (Pin 8) and “ZERO INPUT” pin (Pin 9) from power or ground.
3. Apply power to the probe.
The probe is now in the normal operating mode.
LED Colors
Green: Magnet is present and within the active range.
Red: Fault, the LDT has lost its signal from the magnet or the magnet has moved into the Null or
Dead Zone.
Yellow: The LDT is in the AGC mode, yellow appears in short bursts combined with either red or green
when in the AGC mode.
3.5: Features
Chapter 3: 955QD Overview

Installation, Programming and Maintenance Manual 12
Chapter 3: 955QD Overview
Burst Mode
This feature enables the system to be absolute even though data transfer is through “incremental” method.
In the event of power failure, the controller can be programmed to automatically send a signal to the probe,
which will then respond with the current position data. An input signal to the probe will cause a “burst” of
data, representing the absolute position, to be fed back to the controller.
Zero Pulse
By sending a signal to the probe at any point in the stroke, a new zero point can be established. When using
the burst input, the absolute position provided will be relative to the programmed zero position. In probes
with volatile storage the zero point will be kept until a new zero pulse is sent or until the probe loses power.
Probes with nonvolatile storage will store the zero position even if you lose power. The nonvolatile zero can be
set 100,000 times; the volatile zero can be set an innite number of times.
The type of signal needed for the Burst and Zero inputs:
E = Sinking (PLC Sourcing Outputs)
C = Sourcing (PLC Sinking Outputs)
T = TTL
See section 3.9: Specications for more information or see gure 3.4

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual13
3.6: 955QD
Frequency or Pulse Rate
Selecting the proper frequency in the LDT’s part number is very important. The internal clock inside
of the 955QD interrogates the LDT approximately every 1 millisecond on LDT’s less than 60” in length
and approximately every 2 milliseconds on the units greater than 60” in length. The LDT transmits the
incremental pulses at a xed rate; all incremental pulses must be transmitted before the LDT will interrogate
itself again. The frequency or pulse rate of the 955QD is factory set to 10KHz - 1.00MHz, consult part number
for your model. The input for the PLC or display will determine the frequency needed.
Example: If your PLC High Speed counter card or display accepts a 1MHz encoder input, the choices are:
F1 - 10KHz
F2 = 25KHz
F3 = 50KHz
F4 = 75KHz
F5 = 100KHz
F6 = 150KHz
F7 = 250KHz
F8 = 500KHz
F9 = 1.00MHz
NOTE: If your controller’s maximum input frequency falls between two available frequencies, choose the
lower frequency.
Output Drivers
The 955QD Brik uses a 0L7272 line driver IC. Your LDT was congured at the factory for either a TTL level
output or a 10 - 30VDC level output. Refer to label on LDT for your output type.
D = Differential RS-422 line driver, TTL compatible
L = Differential line driver 10 - 30VDC
V out = V in (LDT Power) -1 volt
Option D has a 5 volt TTL level output regardless of input power.
Option L has an output of 1 volt less than probe input power.
This option is used when driving input cards that are not TTL compatible.

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual 14
3.7: Troubleshooting for 955QD
Troubleshooting describes common problems that may occur when installing the LDT and offers possible
solutions to these problems. If, after reading this appendix, you are unable to resolve a problem, contact our
technical support department at 248-435-0700. Troubleshooting is divided into the following two groups:
• General Checks
• Power Supply
General Checks
Make sure that the magnet is located within the LDT’s active stroke area. Captive magnet assemblies should
be positioned so that they can move freely over the entire area of the active stroke without binding or pushing
on the extrusion. Non-captive magnet assemblies should be situated so that the magnet is no further than
3/8” from the sensing surface at any point in the oating magnet assembly’s movement.
NOTE: Ferromagnetic material (material readily magnetized) should be located no closer than 0.25” from
the sensing surface of the LDT. This includes mounting brackets, magnet spacers, magnet brackets, and
mounting screws. Ferromagnetic material can distort the magnetic eld, causing adverse operation or failure
of the LDT.
Check all LDT wires for continuity and/or shorts. It is preferable that the cable between the LDT and the
interface device be one continuous run. If you are using a junction box, it is highly recommended that the
splice junction box be free of AC and/or DC transient-producing lines. The shield should be carried through
the splice and terminated at the interface device end.
Power Supply Check
This section will help you to determine if your power supply is adequate for the LDT to operate properly, or
if the LDT’s cable has a short or open.
In order for the 955QD to operate properly, the external power supply must provide a level between 10 to 30
VDC. A power supply providing voltage above this specied range may damage the LDT. A power supply
providing power below this specied range will not be sufcient to power the LDT. When powering more
than one Brik on a single power supply, remember that each Brik requires three (3) watts of power maximum
(1 watt typical). The amount of current draw will vary based on the input voltage used. To calculate the
current draw for a particular LDT, divide the LDT wattage by the input voltage. For example, 3 watts divided
by 24 VDC equals 125mA.
If your LDT is not operating properly, the LDT’s cable may have an open or short, or the power supply is not
supplying sufcient power. To verify this, perform the following steps:
1. Turn the power supply off
2. Remove the mating connector from the LDT
3. Turn the power supply on
4. Using a digital voltmeter, check pins 1 (GND) and 2 (+) from the mating end of the cable for a
level between +10 and +30 VDC.

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual15
If reading is between 10 and 30 VDC, turn power supply off and go to step 7. If reading
is below 10 VDC, either your power supply is not providing enough power or the LDT’s cable
possibly has a short/open. Readings of no voltage or minimal voltage (less than 5 volts) may
be due to short/open in the cable. If reading is not between 10 and 30 VDC, go to step
5. If reading is above 30 VDC, adjust power supply or replace.
5. Turn the power supply off.
6. Check the continuity of the individual wires of the cable between the power supply and the LDT.
Check for continuity from one end of the cable to the other. Also verify that no shorts exist
between pins.
7. Reconnect the mating connector to the LDT.
8. Turn power supply on.
9. Using a digital voltmeter, check the power supply’s “+” and “-” terminals for a voltage between
10 and 30 VDC.
Low voltage readings may indicate a power supply with a wattage (current) rating that is too low.
(Each LDT requires 3 watts). If the cabling checks out in step 6 and your voltage is below 10
VDC, check your power supply current rating. If voltage is between 10 to 30 VDC and the LDT is
still inoperative, contact factory.

Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual 16
3.8: Catalog Numbering System for 955QD
955QD 0120
The Series 955QD
The Brik
with Quadrature Output
Stroke in Inches
Insert stroke in inches to 0.1 inch. Enter as a four-
place number. Example: 12.0 in stroke entered as
0120. To convert a metric stroke in millimeters, multi-
ply millimeter value by 0.03937 to arrive at inch value.
H1000 EF7 M1 NXD
Output Resolution
Cycles per inch, maximum internal resolution is 0.001 inches
1000 standard (available range is 0001 through 9999)
Input Type
E = Sinking (typically used with sourcing output type)
C = Sourcing (typically used with sinking output type)
T = TTL Level
Quadrature Cycle Output Frequency Range
F1 = 10 KHz F2 = 25 KHz F3 = 50 KHz F4 = 75 KHz
F5 = 100 KHz F6 = 150 KHz F7 = 250 KHz F8 = 500 KHz F9 = 1.00 MHz
Consult our Technical Support for other output frequencies.
Output Mode
M1 = X1 Quadrature, Consult factory for other output modes
Zero Offset Storage
V = Volatile (nonretentive) N= Nonvolatile (retentive, 100,000 storage cycles maximum)
Output Drivers
D = Differential RS422 line driver, TTL compatible
L = Differential line driver 10 - 30VDC, V out = V in (LDT Power) -1 volt
Connector Style
H = HRS Environmental Connector
Consult factory for others
Options
X = None
NOTE: Contact our Technical Support Department for custom congurations.

Chapter 3: 955QD Overview
3.9: Specications for 955QD
Installation, Programming and Maintenance Manual17
General Specications:
Null Zone 3.00”
Dead Zone 1.50”
Extrusion Assembly Anodized Aluminum with gasket seals, IP 67
Connector HRS-Style Standard (quick connect/disconnect) Connector
Sensor Length Up to 14’
Agency Approval CE
Shock and Vibration
Random Vibration MIL-STD 810E, 10Grms random, 20Hz - 2K Hz
Shock Tested to 40G
Electromagnetic Compatibility
IEC 801-2, Level 3 (Electrostatic discharge requirements)
IEC 801-4, Level 3 (Electrical fast transient/burst requirements)
Electrical Specications
Input Voltage
Unipolar 10 to 30 VDC
Current Draw 3 watts maximum, (1 watt, typical)
Nonlinearity Less than 0.05%
Repeatability +/- 0.001% of full stroke or +/- 0.001” (0.0254 mm), whichever is greater
Operating Temperature -20° to 70° C
Storage Temperature -40° to 85° C
Drivers
Option D 1. Quadrature A: RS-422 differential
2. Quadrature B: RS-422 differential
3. Zero (index) position RS-422 differential
maximum 5 volts, minimum 2 volts into a 50 ohm load
Option L 1. Quadrature A: differential line driver
2. Quadrature B: differential line driver
3. Zero (index) position differential line driver
Maximum 30 VDC, min 10 VDC, driver 0L7272
V out = V in (LDT Power) - 1 volt