ACU-RITE SENC 50 User Manual

SENC 50

REFERENCE MANUAL

Acu-Rite Companies Inc.

SENC 50 Table of Contents

Page

Introduction / Supplied items ............................................... 2

Key Points / Tolerances ......................................................... 3

Linear Encoder Dimensions.................................................. 4

Spar Dimensions .................................................................... 5

Mounting Requirements........................................................ 6

Typical Mounting ................................................................... 7

Encoder Installation Procedure ............................................ 8

Page

Checking the Installation.................................................... 10

Electrical Shielding.............................................................. 11

Troubleshooting ................................................................... 12

Mechanical Specifications ................................................... 13

Output Signals and Pin-Outs.............................................. 14

Electrical Specifications ...................................................... 15

The Acu-Rite Companies Inc.

Hassle Free Warranty & Service ........................................ 16

Spar

Front mount

bracket

Bottom mount

bracket

Adjustable front or

rear mount

Front mount

bracket

Base mount

• Installation brackets and kits are available.

• Your Authorized Distributor can assist you in selecting
brackets and tools for your installation.

1 Acu-Rite Companies Inc.

Introduction / Supplied Items SENC 50

The SENC 50 Precision Glass Scale Linear Encoder provides
the accuracy and reliability of an Acu-Rite Companies Inc.
measuring system in a very small cross-section with digital
output (analog output available). Features and options include:

• Resolutions of 0.5, 1.0 or 5µm.

• Accuracy grades of ± 3 or ± 5 µm / 1000mm.

• Position Trac or 50mm interval Reference Mark.

• Vinyl or Armor cables of 5, 13, & 19 ft. lengths.

• Mounting fasteners, center supports, and backup spar.

• Installation tools, brackets, and accessories.
The SENC 50 is especially useful for applications with limited
space such as X/Y stages and compact metrology equipment.
Contact your Authorized Distributor for assistance with selection
of product options and accessories.

Shipping carton

contents

A

C

For future ordering information or warranty service, record the
linear encoder catalog and serial numbers.

Catalog # Serial # Manufacture Code #
Axis # 1: _____________________________________
Axis # 2: _____________________________________
Axis # 3: _____________________________________
Axis # 4: _____________________________________

Date of Purchase _____________________________________
Distributor: _____________________________________
Address: _____________________________________

Telephone: _____________________________________

B

A) SENC 50 linear encoder
B) Reference Manual
C) Encoder and Cable

Mounting Hardware

Acu-Rite Companies Inc. 2

SENC 50 Key Points / Tolerances

Use this information to plan your Linear Encoder installation.

// .005 A

// .005 B

• Understand your mounting requirements.

• Follow kit instructions when using an Acu-Rite Companies
Inc. bracket kit.

• Mount encoders close to ways to insure system accuracy.

• Mount with lip seals down and away from the work area.

• Brackets should be short and rigid.

• Surfaces must be in good condition, clean and free of
dirt and paint.

• Do not remove shipping brackets until instructed.

• Shipping bracket spacers can be used to insure .059” gap.

-A- = Machine travel
Center support surface

Reading head

assembly

Equal

required

// .005 A

Equal

Gap

.059 ±.005”

[1.50]

Scale assembly

// .005 A

// .005 A

B

• Mount from either side to obtain desired cable exit direction.

• Tolerances of .005” TIR apply to all mounting dimensions.

• Center support surface required for all measuring

lengths when not using a back up spar.

1.00

Shipping bracket removal clearance

Slide brackets away

from the reading head

1.00

Total head travel

.26 [6.6]

Min.

Measuring length + 1”

[25.4] over travel

.037 [.9]

Min.

• Limit equipment travel to less than measuring length.• Allow clearance for shipping bracket removal.

3 Acu-Rite Companies Inc.

Linear Encoder Dimensions SENC 50

.280

[7.11]

Typ.

End cap

.140

[3.55]

.175 [4.57]

.295

[7.50]

Typ.

Reading

head

assembly

.463

[11.76]

.213

[5.41]

Typ.

M3 x .25 [6.31]

deep min.

Measuring length + 4.65 [118]

Measuring length + 4.09 [103.9]

Scale assembly

for M4

Hex nut

Scale case

Mounting hole

Strain relief

1.85

[47.00]

2.775

[70.50]

[4.00] min.

2.350

[59.69]

[3.81]

.138

[3.50]

and cable

Ø .160

.150

.335

[8.51]

Ø .30

[7.6]

Armor

2.0 [50] Approx.
min bend radius

of armor

.280

[7.11]

.159

[4.04] Typ.

Ø .16

[4.1]

Vinyl

.670

[17.00]

1.182

[30.00]

Align both

surfaces

.02

[0.5]

1.352 [34.34]

.652

[16.56]

.482

[12.25]

.Gap

.059 ± .005

[1.50]

.170

[4.32]

.840

[21.34]

Spar

.170

[4.32]

Acu-Rite Companies Inc. 4

SENC 50 Spar Dimensions

Backup spar Linear Encoder L A X No. B

Part Number Measuring Length Places

680803-01 1 5.650 .825 2 4.000
680803-02 2 6.650 .825 2 5.000
680803-03 3 7.650 1.325 2 5.000
680803-04 4 8.650 1.825 2 5.000
680803-05 5 9.650 2.325 2 5.000
680803-06 6 10.650 2.825 2 5.000
680803-07 7 11.650 3.325 2 5.000
680803-08 8 12.650 3.825 2 5.000
680803-09 9 13.650 1.825 3 5.000

Encoder

retaining clip

Spar

fastener

Spar leveling

screws

Backup spar Linear Encoder L A X No. B

Part Number Measuring Length Places

680803-10 10 14.650 2.325 3 5.000
680803-11 11 15.650 2.825 3 5.000
680803-12 12 16.650 3.325 3 5.000

680803-13 13 17.650 3.825 3 5.000
680803-14 14 18.650 1.825 4 5.000
680803-15 15 19.650 2.325 4 5.000

680803-16 16 20.650 2.825 4 5.000
680803-18 18 22.650 1.325 3 10.000

680803-20 20 24.650 2.325 3 10.000

Backup spar mounting optional for all lengths

Backup spar

mounting

Clip mounting

screws

.510

.330

.075

Ø .196 Drill thru

Ø .344 C’bore x .100 Dp.

“X” no. of places

“A”

± .005

Non accumulative

B Typ. ±.005

“A”

Ref.

±.015

L

5 Acu-Rite Companies Inc.

Mounting Requirements SENC 50

Mounting options can be adapted to machine mounting surfaces
using spacers, standoffs, and leveling screws.

• Measuring length and mechanical configuration of your
equipment determines your options.

• Length related mounting options shown.

• When a backup spar is used, mount the backup spar following
the same procedure as required for mounting without a backup
spar, using the same tolerances.

End mounting holes

Center support

assembly

• 8” and larger: End mounting holes with center support.

• 7” and smaller: End mounting holes with encoder mounted to
a continuous flat surface, or with center surface on same plane
as end mounting surfaces.

Acu-Rite Companies Inc. 6

SENC 50 Typical mounting

A variety of mounting conditions can be accommodated.

• Mechanical configuration of the equipment determines
brackets and adapters required to install the linear encoder.

• Three typical conditions are shown for reference.

Flush mounting surfaces

// .005

Spar mounting

// .030

• Flush or offset mounting surfaces using a spar.

• Reading head mounting bracket required (bottom mounting
bracket example shown).

Offset mounting surfaces

// .030

• Mounting surfaces are flush within .005”.

• Installation without a backup spar.

• Offset mounting surfaces using a reading head bracket.

7 Acu-Rite Companies Inc.

Encoder Installation Procedure SENC 50

These steps apply to all mounting conditions. Although this
may not pictorially represent your application, your installation
procedure should follow these steps.

• Acu-Rite Companies Inc. Bracket Kit instructions

supercede this section.

• General steps for small X & Y stage.

• Adjust drill depths and fastener lengths as required.

• Contact your Authorized Distributor if assistance is required.

Keep head and

Scale case

Shipping

brackets (2)

C

L

Reading head

scale case

surfaces flush

Strain relief

and

cable assembly

Center mounting axis

C

Mark center of axis

• Center the axis.

• Mark the axis for easy return to center.

Underside of end caps to be

flush with parting line of

upper slide.

End cap

Align top of scale case to

within .015” of axis travel

Mark end mounting

L

Scale case

hole location

• Center the reading head on the scale case by sliding the head
and shipping brackets together along the scale case.

Acu-Rite Companies Inc. 8

• Locate the linear encoder along the axis parting line.

• Mark location of one end mounting hole in the scale case.

SENC 50 Installation Procedure

Axis

travel

Align to within

.005”

to axis travel

Drill / tap for 6-32

(M3).

Use shipping brackets

to maintain .059

gap between

head and

scale case.

Drill / tap

for 6-32 (M3).

6-32 x 3/4” SHCS & M3

flat washer (M3 x 20mm)

• Drill / tap the first end mounting hole / Attach the scale case.

• Align to within .005” TIR. and drill / tap second end hole.

• Attach scale case & align to within .005” TIR. of the axis travel.

6-32 x 3/4” SHCS & M3 flat washer

(M3 x 20mm)

Retaining clip

Center support

• Use center supports when provided.

• Place at uniform intervals along the scale case.

C

L

6-32 x 3/4” SHCS & M3

flat washer (M3 x 20mm)

• Center the axis and mark the reading head mounting holes.

• Move the axis and drill / tap holes for 6-32 (M3).

• Attach head and align to scale case to within .005” TIR.

Slide bracket from reading head

and twist 45°

Shipping bracket

(2)

• Slide shipping brackets from reading head and twist to remove
from the scale case.

• Save the shipping brackets with the Reference Manual.

9 Acu-Rite Companies Inc.

Checking the Installation SENC 50

Connecting

Provide slack

loops

These steps will confirm proper operation of your installation.
Counting tests check channel A and B output function and
Reference Mark tests check Reference Mark operation.

• Configure the readout for proper counting resolution.

• Move axis and compare the display to the movement.

• Repeat test for mechanical integrity and repeatability.

• Configure the readout for sensing reference mark.

• Move the reading head approximately 20mm.

Secure excess

cable

• Locate an indicator on scale end and zero out axis and
indicator.

• Move axis out and back over full travel and return to dial

• Route the cables with slack loops to allow for axis motion.

• Secure excess cable by fastening with clips or ties.

zero.

• Electronics should read zero ± 1 count.

• Attach the linear encoder connectors to the readout.

Counting Test

Readout

• Check function of the linear encoder.

Acu-Rite Companies Inc. 10

Place indicator at end of

moving component (scale case

shown, or reading head).

Repeatability Test

Readout

• Zero the display and indicator.

• Move axis to the end of it’s travel, then return to dial zero.

• Readout should read zero ± 1 count.

SENC 50 Electrical Shielding

Connect a ground wire from the terminal on the back of the
readout to the machine or earth ground. Attach a ground wire
from the machine to a solid earth ground.

With the encoder attached to the machine and the cable
connected to the readout, check shielding by measuring
resistance between connector housing and scale unit. Desired

value: 1

ΩΩ

Ω max.

ΩΩ

11 Acu-Rite Companies Inc.

Trouble Shooting SENC 50

If you experience difficulties with your installation, there are
methods to analyze the difficulty. Operating difficulties can be
caused by either the linear encoders or the readout.

Checking the readout

Follow the steps below to determine if your difficulties are
associated with the readout:

• Insure that the linear encoder connectors are correctly seated.

• Swap linear encoder cables at the readout to see if the problem
is still shown in the same display.

• If the problem remains in the same display, the readout is in
error.

• If the problem follows the connection change, the linear
encoder may be in error.

• Follow this procedure for any intermittent problem
experienced.

If the readout is at fault, refer to “What to do” to arrange for
the parts necessary to repair your system. If the linear encoders
appear to be the cause, perform the next step.

Checking the Linear Encoders

Linear encoder difficulties can be caused by improper
installation, loose or misaligned bracketry, or a damaged / failed
linear encoder.

Follow the steps below to determine the cause of your system
difficulties:

• Confirm that your bracketry and installation does not interfere

with other machine structures through the length of the linear

encoder travel.

• Check for loose fasteners. If you find loose fasteners, first
confirm that the linear encoder is installed to the tolerances
specified and then retighten the fasteners as required.

• Confirm that the linear encoder is installed to the required
tolerances by checking the alignment tolerances specified on
Page 3 “Key Points”. If the installation does not meet the
tolerances, reinstall the linear encoder according to the
procedures in “Installation”.

• Perform a Repeatability Test as described on Page 10,
“Checking Your Installation”. If the linear encoder is
installed to the required tolerances, the bracketry and linear
encoder have been checked for interferences and loose
fasteners, and the linear encoder fails the repeatability test,
the linear encoder is likely at fault.

Do not attempt to repair the linear encoder. The units are only
serviceable by assembly replacement. Attempted repair can
permanently damage the unit and void the warranty.

What to do

If an Acu-Rite Companies Inc. linear encoder or readout is found
to be at fault, prior to removing the linear encoders or readout
contact your Authorized Distributor or OEM/OEI for repair
instructions.

Acu-Rite Companies Inc. 12

SENC 50 Mechanical Specifications

Mechanical Specifications Digital Analog

Resolution 0.5µm 1µm 5µm

Grating pitch 20µm

Scale medium Light transmission reflective off of chrome coated glass
Accuracy (@ 20° C) / 1000mm ± 3µm, ± 5µm

Max. slew speed (M/s) 1

Force required to move < 0.5 (lbs)

reading head
Operating Environment

Temperature 0° to 50° C
Relative Humidity 20% to 95% (non-condensing)

Storage Environment
Temperature - 20° to 70° C
Humidity 20% to 95% (non-condensing)

Weight 1.1 + 0.2 lbs/ft of measuring length [64g + 5.6g/in.]

Connecting cable Length = 5, 13, and 19 ft. Length = 5, 13, and 19 ft.
armored or vinyl Connector: DE-9P Connector: DE-9P

Max. cable length (ft) 20 26 75

Measuring lengths 1” - 20”
Reference pulse interval 50mm fixed or Position Trac

Repeatability Within one resolution count

Operating current (ma) 220 180 75

Protection (IEC 529) IP 53 when installed as per instruction

13 Acu-Rite Companies Inc.

Output Signals and Pin-Outs SENC 50

Digital Differential

Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8 Pin 9

N/C Green Yellow Pink Red White Black Gray Brown
N/C Channel Channel Channel Channel Ground Vcc, + 5.1 Channel Channel

A+ A- B+ B- ± 0.1 VDC R+ R-

1

5

6

9

Analog Differential

Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8 Pin 9

White w/Grn Stripe & Brown Green Yellow Orange Red N/C Black Blue Violet

Ground Channel Channel Channel Channel N/C Vcc, + 5.0 Channel Channel

A+ A- B+ B- ± 0.1 VDC R+ R-

Acu-Rite Companies Inc. 14

SENC 50 Electrical Specifications

Parameter

Output Signals

Incremental signals

Signal levels

Reference Mark signals

Signal level

Digital

IOH=(High level output current) = 20mA
VOH=(High level output voltage) >2.5Vdc

Channel A+

Channel A-

1
0

1
0

Channel R+

Channel R-

360°

0°

90°

Channel B+

Channel B-

1
0

1
0

1 Count

(Phased)

IOL=(Low level output current) = -20mA
VOL=(Low level output voltage) < 0.6Vdc

Square-wave voltage signals.

Channels A and B, in 90°

quadrature relationship

TTL-level

Square-wave signal

TTL-level

Analog

0°

90°

360°

1
0

1

Channel B

Channel A

I

:7-16 µA

A, B

or

1.0 V

pp

pp

0

Channel R

IR:2-8 µA

1.2 V

pp

or

pp

Similar phasing, but differential

sinusoidal current or 1 volt peak to peak output

7-16µApp or 1.0 V

pp

w/1 K Ohm load

Differential current or 1 volt peak to peak output

2-8µApp or 1.2 V

pp

w/100 K Ohm load

Power Supply

5.1 ± 0.1 VDC @ 220 mA max.

15 Acu-Rite Companies Inc.

5.0 ± 0.1VDC @ 75 mA max.

Acu-Rite Companies Inc. Warranty SENC 50

ACU-RITE Companies, Inc. is proud to offer the 3-Year Hassle-Free Warranty for all readout systems, and precision glass scales.
This warranty will cover all of the ACU-RITE repair and replacement costs for any readout or precision glass scale returned
during the three (3) year warranty period. ACU-RITE will repair or replace the damaged components regardless of the product’s
condition absolutely free, no questions asked. This warranty covers both materials, and factory labor. In addition, authorized
ACU-RITE service representatives will provide service labor (field service) for a period of one (1) year at no charge. Notice of the
claimed defect must be received by ACU-RITE within the warranty period.

This warranty applies only to products and accessories installed and operated in accordance with this reference manual. ACU­RITE shall have no obligation, with respect to any defect, or other condition caused in whole or part by the customer’s incorrect
use, improper maintenance modification of the equipment, or by the repair, or maintenance of the product by any person except
those deemed qualified by ACU-RITE.

Responsibility for loss of operation, or diminished performance due to conditions beyond ACU-RITE’s control cannot be accepted
by ACU-RITE.

The foregoing warranty obligations are in lieu of all expressed or implied warranties. ACU-RITE Companies, Inc. shall not be
liable under any circumstances for consequential damages.

Acu-Rite Companies Inc. 16

Acu-Rite Companies Inc.Acu-Rite Companies Inc.

Acu-Rite Companies Inc.

Acu-Rite Companies Inc.Acu-Rite Companies Inc.

IS ANIS AN

IS AN

IS ANIS AN

ISO 9001ISO 9001

ISO 9001

ISO 9001ISO 9001

CERTIFIEDCERTIFIED

CERTIFIED

CERTIFIEDCERTIFIED

MANUFMANUF

ACTURERACTURER

MANUF

ACTURER

MANUFMANUF

ACTURERACTURER

Acu-Rite Companies Inc.

One Precision Way • Jamestown, NY 14701

516353-21 Ve00 4/2009