Renishaw ATOM User manual

RSLM high accuracy linear encoder
Installation guide
M-9693-9717-03-C
ATOM™rotary encoder systems

ATO M rotary installation guide
Contents
Product compliance 1
Storage and handling 2
ATOM system installation overview 3
RCDM rotary disc installation drawing 4
Mounting the disc 5
Aligning the disc 6
System connection:
Readhead only (no interface) 8
ACi interface 10
Ri interface 12
Ti interface 13
Readhead mounting and alignment:
Methods 14
Shim kit (A-9401-0050) 14
Dummy head (A-9401-0072) 15
Signal amplitude adjustment 15
Calibration overview 16
System calibration (CAL):
Step 1 - Incremental signal calibration 17
Step 2 - Reference mark phasing 17
Calibration routine - manual exit 17
Restoring factory defaults 17
Switching Automatic Gain Control (AGC) on or off 17
LED diagnostics 18
Troubleshooting 19
ATOM readhead:
Cabled readhead dimensions 21
FPC readhead dimensions 22
Output signals 23
ACi interface:
FPC variant 24
Installation drawing 24
Input signals 24
Output signals 24
Cable variant 25
Installation drawing 25
Readhead cable input connector 25
Input signals 25
Output signals 25
PCB variant 26
Input signals 26
Output signals 26
Speed 27
Ri interface:
Interface drawing 28
Output signals 28
Speed 29
Ti interface:
Interface drawing 30
Output signals 30
Speed 31
Electrical connections 32
Output specifications 32
General specifications 33
Disc specifications 33

ATO M rotary installation guide 1
Further information
Further information relating to the AT O M encoder range can be found in the ATO M system Data sheet
(L-9517-9563). This can be downloaded from our website www.renishaw.com/encoder and is also available
from your local representative. This document may not be copied or reproduced in whole or in part,
or transferred to any other media or language, by any means without the written prior permission of Renishaw.
The publication of material within this document does not imply freedom from the patent rights of Renishaw plc.
Disclaimer
RENISHAW HAS MADE CONSIDERABLE EFFORTS TO ENSURE THE CONTENT OF THIS DOCUMENT
IS CORRECT AT THE DATE OF PUBLICATION BUT MAKES NO WARRANTIES OR REPRESENTATIONS
REGARDING THE CONTENT. RENISHAW EXCLUDES LIABILITY, HOWSOEVER ARISING, FOR ANY
INACCURACIES IN THIS DOCUMENT.
Product compliance
ATOM cabled readhead and accessories
C
Renishaw plc declares that ATOM complies with the applicable standards and regulations.
A copy of the EC Declaration of Conformity is available on request.
FCC compliance
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
The user is cautioned that any changes or modifications not expressly approved by Renishaw plc or
authorised representative could void the user’s authority to operate the equipment.
This equipment has been tested and found to comply with the limits for a Class A digital device,
pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with the instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmful
interference in which case the user will be required to correct the interference at his own expense.
NOTE: This unit was tested with shielded cables on the peripheral devices. Shielded cables must be
used with the unit to ensure compliance.
ATOM FPC readhead and ACi
The FPC ATOM and ACi have been designed as system components and to be compliant with
EMC regulations for products of their type. Care must be taken with shielding and grounding
arrangements to ensure EMC performance once installed. It is the system integrator’s responsibility
to implement, test and prove EMC compliance for the whole machine.
RoHS compliance
Compliant with EC directive 2011/65/EU (RoHS)
Patents
Features of Renishaw’s encoder systems and similar products are the subjects of the following
patents and patent applications:
CN101300463B EP1946048 JP5017275 US7624513B2
CN101310165B EP1957943 US7839296 WO2014096764
The use of this symbol on Renishaw products and/or accompanying documentation indicates that
the product should not be mixed with general household waste upon disposal. It is the responsibility
of the end user to dispose of this product at a designated collection point for waste electrical and
electronic equipment (WEEE) to enable reuse or recycling. Correct disposal of this product will help
to save valuable resources and prevent potential negative effects on the environment.
For more information, please contact your local waste disposal service or Renishaw distributor.
The packaging of our products contains the following materials and can be recycled.
Cardboard
Polypropylene
Low Density Polyethylene Foam
Cardboard
High Density Polyethylene Bag
Metalised Polyethylene
Not applicable
PP
LDPE
Not applicable
HDPE
PE
Outer box
Inserts
Bags
Recycling Guidance
ISO 11469
Material
Packaging Component
Recyclable
Recyclable
Recyclable
Recyclable
Recyclable
Recyclable

95% relative humidity
(non-condensing) to
EN 60068-2-78
Humidity
+70 °C
-20 °C
Storage
+70 °C
0 °C
Operating
N-heptane
CH3(CH2)5CH3
Propan-2-ol
CH3CHOHCH3
Scale and readhead
2
ATO M rotary installation guide
Storage and handling

3
ATO M rotary installation guide
ATOM system installation overview
This section gives an overview of the steps involved in installing, setting-up and calibrating an ATOM system. More detailed information is contained within the rest of the document.
For information on designing the readhead and disc into the system refer to the detailed installation drawings and 3D models on www.renishaw.com or contact your local Renishaw representative.
For information on the ATOM product range refer to the ATOM data sheet (L-9517-9466).
IMPORTANT: Prior to installing readhead and disc, installation drawings should be reviewed to ensure correct orientation of readhead relative to disc.
Disc alignment
Optical alignment
using a microscope.
See page 6.
Electrical alignment
Using two readheads.
See page 7.
System connection
Calibrate system
See page 17.
Signal amplitude adjustment.
See page 15.
Dummy head.
See page 15.
Shim kit.
See page 14.
No interface
Connect readhead to
customer electronics.
See pages 8 and 9.
Interface
Plug readhead cable into the interface
and connect to customer electronics.
See pages 10 to 13.
Mount and align readhead

RCDM rotary disc installation drawing Dimensions and tolerances in mm
4
ATO M rotary installation guide
Disc size
(mm)
Line count
20 µm
version
20 µm
version
40 µm
version
40 µm
version
D1
(mm)
D2
(mm)
D3
(mm)
A
(mm)
17
20
25
27
30
36
50
56
68
108
–
–
–
–
4 096
5 000
7 200
8 192
10 000
16 384
1 024
1 250
1 650
1 800
2 048
2 500
3 600
4 096
5 000
8 192
3.275
3.275
6.46
9.625
12.8
12.8
25.5
25.5
25.5
50.9
8.10
11.00
16.10
18.00
21.15
26.90
40.90
47.25
58.55
99.20
16.9
19.9
24.9
26.9
29.9
35.9
49.9
55.9
67.9
107.9
10.63
12.07
14.62
15.57
17.15
20.03
27.03
30.19
35.94
56.26
Radial tolerance
E (mm)
20 µm
version
40 µm
version
–
–
–
–
0.1
0.125
0.125
0.125
0.15
0.2
–
–
–
–
0.075
0.075
0.075
0.1
0.125
0.225
0.1
0.1
0.125
0.125
0.125
0.175
0.2
0.2
0.2
0.2
0.1
0.1
0.075
0.075
0.125
0.2
0.2
0.225
0.3
0.3
Longitudinal tolerance
F (mm)
Optical diameter
(mm)
13.04
15.92
21.01
22.92
26.08
31.83
45.84
52.15
63.66
104.30
0.36
(Pitch tol. ±1°)
2.3
10.25 ± 'F'
Set-up LED
Alignment band for
aligning the disc
on the hub/shaft
Reference mark
D3
D2
D1
0.22
(Roll tol. ±1°)
'A' ±'E'
Glass disc
Black mask 10 µm (±5 µm) thick on reverse of disc
underneath incremental and reference track
For detailed installation drawings, including tolerances, refer to www.renishaw.com
Forward direction
of disc
(increasing count)
FPC cable
Centre of alignment band
Centre of
alignment band
Rideheight (for calibration):
2.5 ±0.08 (40 µm version)
2.5 ±0.04 (20 µm version)
Operating rideheight:
2.5 ±0.11 (40 µm version)
2.5 ±0.055 (20 µm version)

5
ATO M rotary installation guide
Mounting the disc
Mounting surface design
The recommended mounting surface (hub/shaft) profile must allow for the following features:
uOverspill areas either side of the adhesive mounting surface for excess adhesive to run-off.
uSufficient clearance between the disc ID and hub/shaft to allow correct alignment.
uA small height clearance between the disc contact surface and the adhesive mounting surface
to allow application of a controlled thin film of adhesive.
uA maximum outer diameter of the disc contact surface to ensure it is not touching the black mask
on the reverse of the disc. See table below for dimensions.
Cross section of typical hub and disc assembly
Gluing the disc
There are 2 recommended types of adhesives for bonding the disc to the hub/shaft:
uUV cure adhesive (such as Dymax OP4, gel version)
uRoom cure 2-part epoxy (such as Araldite 2014)
1Apply a thin bead of adhesive to the
adhesive mounting surface.
It should be of sufficient quantity only to
fill the gap between the hub and disc.
Small amounts may run-off into adhesive
overspill areas, however these areas
should not be filled with adhesive.
Contact your local Renishaw representative for more information on designing the
mounting surface, suggested materials and adjustment methods.
RCDM disc
Adhesive overspill areas
Adhesive
mounting surface
Customer hub
Clearance between disc ID
and hub/shaft
Black mask
Disc contact surface
108
97.3
68
56.66
56
45.36
50
39.04
36
25.04
30
19.28
27
16.12
25
14.2
20
9.52
17
*
Disc size (mm)
Maximum OD
of disc contact
surface (mm)
*17 mm disc can be mounted on black mask due to space constraints. All other size discs the black mask must not impede the disc contact surface.
3Align the disc so it is concentric with the hub/shaft.
4Cure the adhesive.
2Using a weight (or similar) ensure the disc touches the hub/shaft over the entire disc contact surface.
Movement of disc during
alignment procedure
Weight
Adhesive
mounting surface
Bead of
adhesive
Disc contact
surface
Weight
See cross section drawing

2Rotate the disc/hub assembly and observe the maximum and minimum limits of movement
of the alignment band as shown below.
3Note the axis position at the limits of movement.
4Rotate the disc so either of these limits of movement is located under the microscope.
5Gently move the disc relative to the hub in a radial direction so the alignment band
moves half way between the limits of movement.
NOTE: The alignment band is 30 µm wide.
Position of disc at limit of movement of alignment band.
6Rotate the assembly and repeat steps 3-5 until the total alignment band
movement is within the design specifications.
7Cure the adhesive.
8Recheck the run-out.
6
ATO M rotary installation guide
Aligning the disc
There are two possible ways to accurately align the disc to minimise eccentricity:
uOptical alignment using a microscope
uElectrical alignment using two readheads
The method chosen to align the disc on the system depends upon the application and available
space, etc. It should be noted that the graduations and alignment band are accurately concentric
with each other but not with the glass disc. The following sections outline how to align the disc
using these methods.
NOTE: The disc should not be mounted on the black mask on the reverse of the disc
(apart from 17 mm disc).
Optical alignment
This method uses a microscope, which could be connected to a camera,
to monitor the movement of the alignment band as the disc is rotated.
1Position the microscope/camera over the alignment band on the disc so that any
displacement of the alignment band due to rotation of the disc/hub assembly
can be observed.
RCDM disc/hub
assembly
Microscope
and camera
Alignment
band
Maximum movement
Minimum movement
0° Rotation 90° Rotation 180° Rotation 270° Rotation
Contact your local Renishaw representative for more information on aligning the disc.
Direction of
movement
Alignment band
Microscope
Position of maximum or
minimum limit of movement
of the alignment band

7
ATO M rotary installation guide
Electrical alignment
This method involves monitoring the output signals of two readheads mounted 180 degrees apart
and adjusting the disc to minimise the difference in count between the two heads.
NOTE: Due to spacing it is not possible to use this method on disc smaller than 22 mm diameter.
This requires:
uA DSi interface
u2 x Ri or Ti interfaces
uA digital counter
The clock frequency of the DSi, interfaces and digital counter must be matched to ensure there is no
miscounting. For more information on choosing appropriate DSi and interfaces for your system contact
your local Renishaw representative. For more information on the DSi refer to the TONiC DSi data sheet
(L-9517-9466).
4Restore factory defaults on both ATOM systems by pressing and holding the CAL button on both
interfaces whilst switching the system on. This can be done individually or whilst the interfaces
are plugged into the DSi. See page 17 for more information.
5Using a custom designed bracket adjust both readheads to maximise the signal strength for
a complete rotation of the axis (readhead set-up LED should be Green on both readheads)
6Rotate the axis until the count displayed on the customer counter is at its minimum.
NOTE: If the count continues to increase then the orientation switch on the DSi is not in the
correct position.
7Rotate the axis to the minimum count position and reset the counter to zero.
8Rotate the axis until a maximum count is displayed. This should ~180° from the position when
the count is minimum.
9Gently move the disc relative to the hub in a radial direction at 90° to the readheads, as shown below,
until the count displayed on the customer counter is reduced by approximately half.
3Power the system.
10 Repeat steps 6 - 9 until the difference in (maximum count) – (minimum count) is within
the design specifications.
11 Cure the adhesive.
12 Recheck the run-out.
Contact your local Renishaw representative for more information on aligning the disc.
1Connect system as shown above.
2Set the orientation switch on the reverse of the DSi to ‘difference’ mode.
INPUT 1
DSi
INPUT 2
Customer
counter
Factory
setting
Difference mode
or
Direction of
movement

8
ATO M rotary installation guide
System connection: Readhead only (no interface)
The ATOM readhead is available in several variants:
uCable variant with a 15 way D-type connector
uCable variant with interboard connector
uFPC variant
None of these readhead variants has an integral calibration (CAL) button. Provision should be made
in the customers’ electronics for momentarily connecting the CAL line to 0 V to initiate the calibration
routine, switch AGC on/off or restore factory defaults. See page 23 for pin-out information.
Calibration is an essential part of system set-up that optimises the incremental signals and
phases the reference mark. See page 17 for information on the calibration routine.
For cable variant with interboard connector
uEnsure that the interboard connector is inserted into the connector on the customers’ electronics
NOTE: Care should be taken to ensure correct orientation
uUse a metal clamp around the cable ferrule to ground the readhead cable and ensure continuity
of the shields
uProvide appropriate strain relief
uEnsure suitable clamping to retain interboard connector to the mating connector
For FPC variants
Ensure that the FPC cable being used has the following specifications:
u16 core
uConductor pitch 0.5 mm
uMinimum exposed conductor strip length 1.5 mm
uMaximum exposed conductor strip length 2.5 mm (to ensure isolation from the body)
Contact your local Renishaw representative for more information of the FPC design requirements.
Shielding
For optimum performance:
uEnsure 100% shielding
uGround the mounting brackets
uEnsure continuity of all shields
uMaximise the distance between the encoder and motor cables
uProvide appropriate strain relief at the readhead
JST 12 way,
single row
12SUR-32S
Interboard connector
14 way, dual row
DF23C-14DS- 0.5 V
1
2
13
14
Interboard
connector
PCB FPC
connector
FPC
cable
Readhead LED
Shield
connect pad
0-0.5 mm
4 mm
Example of strain relief:
3.25 mm

9
ATO M rotary installation guide
Removing the FPC cable
1Placing your finger on the whole of the
locking lever, slowly lift it up and away to
disengage the locking mechanism.
Do not use tools such as screwdrivers
or tweezers to open the locking lever
as this may cause damage to the
connector or PCB.
3Pull the FPC cable straight back to remove it.
Do not pull upwards or sideways as
this may damage the readhead.
2Ensure locking lever is fully open before
removing the FPC cable.
Inserting the FPC cable
1Ensure the locking lever is up (open) before fully
inserting the FPC cable into the connector.
NOTE: Check correct orientation of cable before
inserting into the connector. Readhead will be
shipped with connector in the open position.
3When the system has been connected, proceed with
‘Readhead mounting and alignment’ and
‘System calibration’ sections.
2Applying pressure to the whole locking lever
push it down to lock the FPC cable in place.
NOTE: Do not push the locking lever down if
no FPC cable is inserted as this will damage
the locking mechanism.
The FPC cable must be connected before fitting the readhead lid. The lid is secured by the readhead mounting screws.
Approved ESD precautions must be followed at all times during readhead electrical connection.

10
ATO M rotary installation guide
Ensure that the FPC cable being used has the following specifications:
u16 core
uConductor pitch 0.5 mm
uMinimum exposed conductor strip length 1.5 mm
uMaximum exposed conductor strip length 2.5 mm (to ensure isolation from the body)
Contact your local Renishaw representative for more information of the FPC design requirements.
Shielding
For optimum performance:
uEnsure 100% shielding
uGround the mounting brackets, readhead and FPC cable clamp
uEnsure continuity of all shields
uMaximise the distance between the encoder and motor cables
uProvide appropriate strain relief at the readhead and interface
uThe ACi should be contained within a shielded enclosure
Mounting
ACi can be mounted to customers’ system using 2 off M3 screws or 2 off M2.5 screws for through mounting.
Output
The output connector is a 10 way JST, GH crimp connector with 1.25 mm pitch.
It is suitable for cable size 26 to 30 AWG. See page 24 for pin-out information.
Connection
For information on inserting and removing the FPC cable to the ACi and readhead see page 9.
Approved ESD precautions must be followed at
all times during readhead electrical connection.
The FPC cable must be connected to the readhead before fitting the lid.
The lid is secured by the readhead mounting screws.
Cable variant
Shielding
For optimum performance:
uEnsure 100% shielding
uGround the mounting brackets
uUse a metal clamp around the cable ferrule to ground the readhead cable
uEnsure continuity of all shields
uMaximise the distance between the encoder and motor cables
uProvide appropriate strain relief at the readhead and interface
uThe ACi should be contained within a shielded enclosure
uEnsure suitable clamping to retain interboard connector to the mating connector
Mounting
ACi can be mounted to customers’ system using 2 off M3 screws or 2 off M2.5 screws for through mounting.
Output
The output connector is a 10 way JST, GH crimp connector with 1.25 mm pitch.
It is suitable for cable size 26 to 30 AWG. See page 25 for pin-out information.
Approved ESD precautions must be followed at
all times during readhead electrical connection.
JST output
connector
2 mounting holes
M3 through
PCB
Cable
interboard
connector
Cable
interboard
connector*
*Ensure suitable clamping to retain interboard connector on ACi.
Ferrule
System connection: ACi interface
FPC variant
2 mounting holes
M3 through
JST output
connector
FPC input
connector
PCB
FPC
cable
FPC input
connector
Pin1
Pin1

System connection: ACi interface
PCB mounting: connecting an FPC variant ATOM readhead
Ensure that the FPC cable being used has the following specifications:
u16 core
uConductor pitch 0.5 mm
uMinimum exposed conductor strip length 1.5 mm
uMaximum exposed conductor strip length 2.5 mm (to ensure isolation from the body)
Contact your local Renishaw representative for more information of the FPC design requirements.
Shielding
For optimum performance:
uEnsure 100% shielding
uGround the mounting brackets, readhead and FPC cable clamp
uEnsure continuity of all shields
uMaximise the distance between the encoder and motor cables
uProvide appropriate strain relief at the readhead and interface
Connection
For information on inserting and removing the FPC cable to the mating socket see page 9.
Approved ESD precautions must be followed at
all times during readhead electrical connection.
The FPC cable must be connected to the readhead before fitting the lid.
The lid is secured by the readhead mounting screws.
PCB mounting: connecting a cable variant ATOM readhead
Shielding
For optimum performance:
uEnsure 100% shielding
uGround the mounting brackets
uUse a metal clamp around the cable ferrule to ground the readhead cable
uEnsure continuity of all shields
uMaximise the distance between the encoder and motor cables
uProvide appropriate strain relief at the readhead and interface
uThe ACi should be contained within a shielded enclosure
uEnsure suitable clamping to retain interboard connector to the mating connector
Approved ESD precautions must be followed at
all times during readhead electrical connection.
FPC input
connector
FPC cable
2 mounting holes
M3 through
Output
Customer PCB
Input
ACi interface
Ferrule
2 mounting holes
M3 through
Output
Customer PCB
Input
Cable interboard
connector*
ACi interface
11
ATO M rotary installation guide
Pin1
Pin1

12
ATO M rotary installation guide
System connection: Ri interface
Approved ESD precautions must be followed
at all times during readhead and interface
electrical connections.
The readhead is connected to the Ri interface
via a small, rugged connector to allow for easy
feed-through during installation.
NOTE: An optional Ri cable guide (A-9693-2577)
is available to simplify assembly.
For instructions on how to install the Ri cable guide,
download ‘Ri interface cable guide’ from the website at
www.renishaw.com/encoderinstallationguides
Readhead
connection
socket
Connecting the readhead
1Open the interface housing by removing
the 2 screws shown.
(4-40 UNC screws and nuts)
2With the plain side uppermost,
remove the top half of the housing,
so that the interface PCB is exposed
and the readhead connection socket
is visible.
3Taking care not to touch the pins,
plug the connector into the socket
in the interface, ensuring correct
orientation as shown.
NOTE: Care is required to hold the
assembly together as the PCB is fixed
only to the 15 way connector and the
jack screws are loose.
4Reassemble the housing ensuring the
cable ferrule is located in the recess
on the inside and no wires are trapped.
5Refit the screws.
6When the system has been connected,
proceed with ‘Readhead mounting
and alignment’ and
‘System calibration’ sections.
Disconnecting the readhead
1Disconnect power.
2Open the interface housing as detailed earlier in this section.
3Gently lever the connector PCB (on the end of the cable) out of the socket.
4Place the connector in an anti-static bag.
5Reassemble the interface.
Ensure ferrule
is located in
housing recess

13
ATO M rotary installation guide
System connection: Ti interface
Approved ESD precautions must be followed
at all times during readhead and interface
electrical connection. The readhead is
connected to the Ti interface via a small,
rugged interboard connector to allow for
easy feed-through during installation.
Connecting the readhead
1Remove the cover plate as shown
(2 off M2.5 hex head screws).
2Taking care not to touch the pins,
plug the connector into the
socket in the interface,
ensuring correct orientation as shown.
3Refit the cover plate ensuring the cable ferrule is located in the recess on the inside and no wires are trapped under the cover plate.
4When the system has been connected proceed with ‘Readhead mounting and alignment’ and ’System calibration’ sections.
Disconnecting the readhead
1Disconnect power.
2Remove the cover plate on the interface
(2 off M2.5 hex head screws).
3Gently lever the connector PCB
(on the end of the cable) out of the socket.
Do not pull the cable to remove the connector.
4Place the connector in an anti-static bag.
5Refit the cover plate.

14
ATO M rotary installation guide
Readhead mounting and alignment: Methods
There is a range of tools available to assist with readhead installation depending
upon the system design, these are detailed below.
For more details on designing the mounting bracket and selecting the appropriate
mounting tools contact your local Renishaw representative.
uEnsure that the disc, readhead optical window and mounting face are clean
and free from obstruction. Do not saturate the readhead window with cleaning
solvent as this may cause contamination on the inside of the readhead
window which then cannot be cleaned.
uAGC should be switched off before installing the readhead and,
when reinstalling, factory defaults should be restored.
NOTE: For FPC readheads the FPC cable must be fitted prior to mounting
the readhead. See page 9 for more details.
IMPORTANT: Whichever method is used to mount the readhead, care should
be taken to ensure the scale surface is not damaged during this operation.
Shim kit (A-9401-0050)
This method is intended for applications where the rideheight of the
readhead cannot be adjusted.
Shims of a known thickness are inserted between the mounting face of the
readhead and the bracket to give the correct rideheight.
The kit consists of:
The system should be designed to achieve a nominal 2.3 mm (±0.2 mm)
from the readhead mounting surface to the disc surface.
Disc
Mounting
bracket
Location pins
2.3 ±0.2 mm
1Using a digital dial gauge or similar measure the distance from
the readhead mounting surface to the disc surface.
Care must be taken to ensure the disc surface is not scratched.
Renishaw offer a DTI adapter (A-9401-0105) that can be used
to assist with this process.
– Insert the gauge into the adapter and zero the gauge
on a flat surface.
– Position or fix the gauge/adapter in place of the readhead
and measure the distance to the disc surface.
Contact your local Renishaw representative for details of the
DTI adapter and digital dial guage.
2Subtract the distance measured from the nominal rideheight of
2.5 mm to calculate the required shim thickness.
For example if the distance measured is 2.37 mm the required
shim thickness is 130 µm.
3Select a combination of two shims that gets within 10 µm
of the difference. For distances less than 100 µm a single shim
should be used, for distances greater than 100 µm select one
thick ( 100 µm) and one thin (<100 µm) shim.
In the above example this could either be:
1 x 100 µm shim and 1 x 40 µm shim or
1 x 100 µm shim and 1 x 20 µm shim.
4Place the chosen shim(s) between the readhead and the bracket.
5Fix the readhead to the bracket using 2 off M2 x 6 screws in
diagonally opposite fixing holes ensuring readhead is
tightened down evenly and parallel to the bracket face.
Using location pins/shoulder:
6Ensure the readhead is pushed back against the location pins
or shoulder.
7Tighten the fixing screws.
8Check the readhead set-up LED is Green around the full axis
of rotation.
9Proceed with ‘System calibration’ section.
Not using location pins:
10 Adjust longitudinal and radial offset of the readhead to obtain
a Green readhead set-up LED around the full axis of rotation.
An oscilloscope or Renishaw USB set-up tool kit and software
can be used to help maximise the signal size.
For more information on the Renishaw USB set-up tool kit
contact your local Renishaw representative.
11 Tighten the readhead fixing screws.
12 Proceed with ‘System calibration’ section.
Part Number: A-9401 A- 9401 A-9401 A-9401 A- 9401 A- 9401 A-9401
-0041 -0042 -0043 - 0044 - 0045 -0046 -0047
Thickness (µm) 20 40 60 80 100 200 300
Quantity in pack 10 10 10 10 20 20 10
DTI adapter
RCDM
disc

15
ATO M rotary installation guide
Dummy head (A-9401-0072)
The reuseable dummy head has the same dimensions as the ATOM readhead with
a longer ‘nose’ that is machined to the optimum rideheight (2.5 mm ±0.02 mm).
It is mounted in place of the readhead directly onto the bracket. The bracket should
have location pins or a shoulder to control readhead yaw. Contact your local
Renishaw representative for more information on bracket design.
1Mount the dummy head onto the bracket using
2 off M2 x 6 screws.
2Loosely mount the readhead bracket onto the axis.
3Adjust the height of the bracket or disc assembly until
the ‘nose’ of the dummy head just touches the disc.
4Tighten bracket fixing screws whilst ensuring good contact
between the ‘nose’ of the dummy head and the surface
of the scale.
5Install the ATOM readhead in place of the dummy head using
2 off M2 x 6 screws in diagonally opposite fixing holes.
Using location pins/shoulder:
6Ensure the readhead is pushed back against the location pins
or shoulder.
7Tighten the fixing screws.
8Check the readhead set-up LED is Green around the full axis
of rotation.
9Proceed with ‘System calibration’ section.
Not using location pins:
10 Adjust longitudinal and radial offset of the readhead to obtain a Green readhead set-up LED around
the full axis of rotation. An oscilloscope or Renishaw USB set-up tool kit and software can be used to
help maximise the signal size. For more information on the Renishaw USB set-up tool kit contact your
local Renishaw representative.
11 Tighten the readhead fixing screws.
12 Proceed with ‘System calibration’ section.
Signal amplitude adjustment
Mount the readhead directly onto a bracket, then, using the Renishaw USB set-up tool kit and software
or oscilloscope, adjust the readhead to maximise the signal size.
For more information on bracket design and the Renishaw USB set-up tool kit contact your local
Renishaw representative.
For more information on system tolerances refer to the installation drawings on www.renishaw.com
1Mount the readhead onto the bracket using 2 off M2 x 6 screws.
2Loosely mount the readhead bracket onto the axis.
3Using the Renishaw USB set-up
tool kit or an oscilloscope adjust
the yaw, pitch and rideheight
of the readhead to maximise
the signal strength.
4Tighten the bracket and readhead fixing screws.
5Check the readhead set-up LED is Green around the full axis of rotation.
6Proceed with ‘System calibraton’ section.

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ATO M rotary installation guide
Calibration overview
Calibration is an essential operation that completes readhead set-up, with the optimum incremental and reference mark signal settings stored in the readhead’s non-volatile memory.
This section is an overview of the calibration procedure for an ATOM system.
More detailed information on calibrating the system is on page 17.
The system is now calibrated and ready for use.
AGC can now be switched on if required.
NOTE: If calibration fails (readhead set-up LED continues flashing Blue),
restore factory defaults, check the readhead installation and repeat the calibration routine.
Reference mark not used
Manually exit calibration routine.
The readhead set-up LED will stop flashing Blue.
Reference mark
Rotate the readhead back and forth over the reference mark
until the readhead set-up LED stops flashing Blue.
Ensure AGC is switched off.
Systems are shipped with AGC switched off.
When AGC is switched off the readhead set-up LED will be Green, Orange or Red.
Align the readhead to maximise signal strength over the full rotation.
The readhead set-up LED will be Green.
Initiate Incremental signal calibration routine.
The readhead set-up LED will be single flashing Blue.
Rotate the axis at slow speed (<100 mm/s).
The readhead set-up LED will start double flashing Blue.

17
ATO M rotary installation guide
System calibration (CAL)
Calibration is an essential operation that completes readhead set-up, with the optimum incremental
and reference mark signal settings stored in the readhead’s non-volatile memory.
Before system calibration:
uClean the disc and readhead optical window
uIf reinstalling, restore factory defaults.
uEnsure AGC is switched off (readhead set-up LED is Green, Red or Orange).
uMaximise the signal strength for complete rotation around the disc. (readhead set-up LED is Green)
NOTE: CAL routine maximum speed <100 mm/s.
Step 1 – Incremental signal calibration
uInitiate calibration routine.
uThe readhead set-up LED will now periodically single-flash Blue to indicate that it is in the incremental
signal calibration routine. The set-up signal (VX) will be a nominal 0 V.
uRotate the readhead around the disc, ensuring you do not pass a reference mark, until the readhead
set-up LED starts double-flashing Blue. This indicates the incremental signal is now calibrated and
the new settings are stored in the readhead memory. The set-up signal (VX) will be a nominal 1.65 V.
uThe system is now ready for reference mark phasing.
uFor systems without reference mark, go to ‘Calibration routine - manual exit’
uIf the system does not automatically enter the reference mark phasing stage (no double-flashing Blue
of the readhead set-up LED) the calibration of the incremental signals has failed. After ensuring failure
is not due to overspeed (>100 mm/s), exit the calibration routine, restore factory defaults and check the
readhead installation and system cleanliness before repeating the calibration routine.
Ti interface
Press the CAL button
on the end of the
interface for
<2 seconds
using a
2 mm
allen key or
similar tool.
WARNING! Activating the CAL
switch only requires 2.5 N force.
Applying excess force may
permanently damage the switch.
No interface
Ground the
CAL pin for
<2 seconds
ACi interface
Connect the CAL pads
together or ground the
remote CAL line (pin 8)
for <2 seconds
Ri interface
Press the CAL button
on the side of the
interface for
<2 seconds
using a
2 mm
allen key or
similar tool.
WARNING! Activating the CAL
switch only requires 2.5 N force.
Applying excess force may
permanently damage the switch.
CAL
button
2 CAL
pads
Step 2 – Reference mark phasing
uRotate the readhead back and forth over the reference mark until the readhead set-up LED stops flashing
and remains Green. The reference mark is now phased. The set-up signal (VX) will be a nominal 3.3 V
depending upon system set-up (see ‘Interface output specifications’ for more details).
uThe system automatically exits the CAL routine and is ready for operation.
uIf the readhead set-up LED continues double-flashing Blue after passing the reference mark many times,
it is not detecting the reference mark. Ensure that the readhead orientation and lateral offset are correct.
Calibration routine – manual exit
uThe calibration routine can be exited at any stage. Depending upon the interface used follow the relevant
section in the table below to exit CAL mode.
uOn successful exit the readhead set-up LED will stop flashing Blue and remain Green or Red.
Restoring factory defaults
When realigning the readhead, reinstalling the system, or in the case of continued calibration failure,
factory defaults should be restored.
To restore factory defaults:
uSwitch system off, then switch on again using the following methods depending on interface used.
uThe readhead set-up LED will flash Blue four times on switch on.
uRelease CAL button, CAL pads link or CAL pin ground.
uCheck the ‘Readhead mounting/installation’ and recalibrate the system.
NOTE: System must be recalibrated after restoring factory defaults.
Switching Automatic Gain Control (AGC) on or off
AGC can be switched on or off via the interface or the CAL line.
uThe readhead set-up LED will be Green with the addition of Blue when AGC is active.
NOTE: The system must be calibrated before switching AGC on.
No interface
Ground and hold the
CAL pin whilst switching
the system on.
ACi interface
Connect the CAL pads
together or ground the
remote CAL line (pin 8)
whilst switching the
system on.
Ri interface
Press and hold the CAL
button on the side of the
interface whilst switching
the system on
Ti interface
Press and hold the
CAL button on the end
of the interface whilst
switching the system on
No interface
Ground the CAL pin for
<2 seconds.
ACi interface
Connect the CAL pads
together or ground the
remote CAL line (pin 8) for
<2 seconds.
Ri interface
Press and hold the CAL
button on the side of the
interface for <2 seconds.
Ti interface
Press the CAL button on
the end of the interface for
<2 seconds.
No interface
Ground the CAL pin for
>3 seconds then remove
ground link
Ri interface
Press and hold the CAL
button on the side of the
interface for >3 seconds
then release
ACi interface
Connect the CAL pads
together or ground the
remote CAL line (pin 8) for
>3 seconds then disconnect
Ti interface
Press and hold the CAL
button on the end of the
interface for >3 seconds
then release

18
ATO M rotary installation guide
Ti interface
* Alarm output will take the form of 3-state or line driven E- signal depending on interface configuration.
Also, some configurations do not output overspeed alarm. See product nomenclature for details.
-Momentary status only, while fault condition remains.
-Alarm may result in axis position error, re-datum to continue.
Normal setup; signal level 110% to 135%
Optimum setup; signal level 90% to 110%
Normal set-up: signal level 70% to 90%
Acceptable set-up; signal level 50% to 70%
Poor set-up; signal may be too low for reliable operation;signal level <50%
Poor set-up; signal level <20%; system in error
Over speed; system in error
Over signal; system in error
Reference mark detected (speed <100 mm/s only)
Status
Indication
Signal
Purple
Blue
Green
Orange
Red
Red / blank - flashing
Blue / blank - flashing
Purple / blank - flashing
Blank flash
Incremental
Reference mark
Alarm output*
No
No
No
No
No
Ye s
Ye s
Ye s
No
*When stationary will be Green or Red.
=Flash will effectively be invisible when incremental signal level is >70% when passing reference mark.
‡When AGC is enabled the LED indication will be as shown but with the addition of a Blue indication.
Normal set-up; signal level >70%, AGC off
Acceptable set-up; signal level 50% to 70%, AGC off
Poor set-up; signal may be too low for reliable operation; signal level <50%, AGC off
Calibrating incremental signals
Calibrating reference mark
Normal phasing
Acceptable phasing
Poor phasing; clean disc and recalibrate if required
Factory defaults restored
Status
Indication
Green
Orange*
Red
Single Blue flashing
Double Blue flashing
Green (flash)=
Blank (flash)
Red (flash)
4 Blue flashes on switch on
Incremental
(AGC off)‡
CAL
Reference mark
Restore factory defaults
Signal
LED diagnostics
Readhead
The readhead set-up LED consists of a tri-coloured LED which can display any combination of Red, Blue or Green.