Newall DP900 User manual

Digital Readout Display
D 900 Manual

i
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Back . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Screen layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Using the Help system . . . . . . . . . . . . . . . . . . . . . . 2
General information. . . . . . . . . . . . . . . . . . . . . . . . . 2
Slider bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Information bar. . . . . . . . . . . . . . . . . . . . . . . . . . .3
Manual conventions . . . . . . . . . . . . . . . . . . . . . . . 3
Save and exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Exit without saving . . . . . . . . . . . . . . . . . . . . . . . .3
Soft keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General operation . . . . . . . . . . . . . . . . . . . . . . . . 3
Other functions. . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Front panel dedicated keys. . . . . . . . . . . . . . . . . . . 5
Sleep mode key . . . . . . . . . . . . . . . . . . . . . . . . . 5
abs/inc key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
in/mm key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Ref key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Alphanumeric keypad . . . . . . . . . . . . . . . . . . . . . . . 6
Numeric keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Navigation keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Setup mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
General settings . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
No. of axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Sleep mode time (min). . . . . . . . . . . . . . . . . . . . .9
Key beep enable . . . . . . . . . . . . . . . . . . . . . . . . . 9
Zero app. beep en . . . . . . . . . . . . . . . . . . . . . . . . 9
Zero app. tolerance . . . . . . . . . . . . . . . . . . . . . . . 9
Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Select axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Machine model. . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Auxiliary setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Set factory settings. . . . . . . . . . . . . . . . . . . . . . . .12
Applying compensation. . . . . . . . . . . . . . . . . . . . . . 12
Error descriptions. . . . . . . . . . . . . . . . . . . . . . . . . 12
Calibrate axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Linear compensation . . . . . . . . . . . . . . . . . . . . . . 14
Segmented compensation . . . . . . . . . . . . . . . . . . 15
Basic functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Absolute mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Incremental mode . . . . . . . . . . . . . . . . . . . . . . . . . .17
Inch and mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Loading an axis. . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Preset mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Referencing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Setting the machine reference . . . . . . . . . . . . . . . 18
Finding the machine reference. . . . . . . . . . . . . . . 19
Digital encoder reference. . . . . . . . . . . . . . . . . . . 19
Graphical zoom. . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Calculator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

ii
Contents
Mill functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Bolt hole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Line hole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Arc contouring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
R-function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Pocket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Polar coordinates . . . . . . . . . . . . . . . . . . . . . . . . . .27
Axis summing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Zero approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Job timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Probe function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Datum axis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Linear measurement mode . . . . . . . . . . . . . . . . . 29
Angle measurement mode. . . . . . . . . . . . . . . . . .29
Diameter measurement mode . . . . . . . . . . . . . . . 30
Lathe functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Summing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Vectoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Taper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Zero approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Job timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Generic functions . . . . . . . . . . . . . . . . . . . . . . . . . 33
Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Mill mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Lathe mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Sub datums. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Creating a job. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Editing a job . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Using sub datums . . . . . . . . . . . . . . . . . . . . . . . . 37
Auxiliary function. . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

1
Introduction
Introduction
This chapter describes the basics of the DP900 DRO.
The DP900 is available with 2, 3 or 4-axes of encoders. The 4th, 'W', axis
can be a Newall Spherosyn/Microsyn (analog) or an RS422 TTL
diferential (digital) depending on the specific unit. You can set the RS422
TTL W-axis to show linear or angular measurement.
Depending on the options that you choose, there may also be extra
connections for a probe and an auxiliary input/output port.
The mains on/off switch is at the rear of the unit, see the diagram on
page 1.
You should always connect the equipotential terminal to the machine
ground to ensure that the displays are stable.
Front
Back
Numeric keys
Slider bar
Display screen
Navigation keys
Function keys
Soft keys
Power on/off
Power inlet Earth terminal 1st, 2nd & 3rd axis -
Newall encoders
USB ‘B’ type
Probe inputAuxiliary input/output
4th axis (Newall encoder) or
RS422 encoder input

2
Introduction
Screen layout
Using the Help system
The DP900 has a comprehensive context-sensitive help system.
The [help] key takes you to context-sensitive help so you can find the
specific information you require quickly without the need to search through
pages of information. If you press the [help] key while you are performing
a particular operation, then you see the help screen for the function that
you are currentlyusing. You can also navigate to other topics, by pressing
from within the Help function. This takes you to a list of contents, from
where you can select the subject that you want.
The Help menus use a principle similar to HTML hyperlinks such that any
item described within the Help text that isenclosed within angled brackets,
<>, acts as a link. You can page through help pages using the up and
down navigation keys and through the links using the left and right
navigation keys. When you select a link, the text inverts. You press the
[enter] key or the [arrow-centre] key to jump to that help page. When you
have followed links, you can press to move back through previous
pages.
When you have finished with the help, press to return to the
operation you were performing.
General information
• You enter numeric values using the keypad.
• You use the [enter] key to confirm your numeric entry and return to the
previous screen while saving the parameters.
• You use the [ce] key to clear your numeric entries and return to the
previous screen without saving the parameters.
• The {soft key} labels show the various functions available. You select
these by pressing the corresponding key below the label. There are
two levels of soft keys, which you access using the left and right
navigation keys.
• You use the up and down navigation keys to move between different
fields within forms or list boxes.
Slider bar
Unlike a conventional DRO there are no dedicated axis key positions.
Instead, there is a slider bar that can be used in a far more flexible
manner.
In normal operation, you press the region of the slider bar next to the
displayed axis value for it to act in the same manner as a traditional axis
key. This allows for zeroing or loading values into that axis. However, in
some modes the axis position display can move to make room for
graphics or additional information. When this happens, the axis active
position on the slider bar moves to remain next to the axis displayed value
ZeroApproach
Bar Graph
Measurement
Unit ABS/INC
Mode
Display Area
Tool No. Feed Rate Set/Zero Mode
Axis Labels
Soft Key
Labels

3
Introduction
on the screen. In some modes, you can use the slider bar to scroll through
lists of data in much the same manner as on a PC.
The flexibility of the slider bar also means that for some complex
functions, such as the calculator function, additional soft keys can be
made available.
Information bar
The top of the DP900 graphical display shows the current user basic
display options. It also shows the current Feed-rate, Tool selection and
simple messages. For example, if you press a key with no allocated
function, the display shows 'Illegal key'. The message remains for a few
seconds before automatically clearing and it is accompanied by two short
beeps.
Manual conventions
In this manual, the following notations are used:
[name] denotes a dedicated key name.
{name} denotes a soft key name.
Save and exit
In Setup mode, if you make changes and want these to be stored
permanently you need to select 'Save and Exit'. Pressing then
saves your changes and you leave Setup mode.
Exit without saving
In Setup mode, if you have made changes but do not want them to be
actioned you need to select 'Exit without Saving'. When you press
you leave Setup mode without saving or actioning any changes.
Soft keys
General operation
The order of the soft keys changes according to whether you have
selected Mill or Lathe as your machine model. You press the right
navigation key to scroll through all the available soft keys.
Func ( ). You use this to display a machine-specific functions list. This
is explained in more detail in Lathe functions, Mill functions and Generic
functions.
Set/Zero ( ). You use this to toggle between Setting and Zeroing an
axis on the axis keys.
Tools ( and ). You use this to enter the Tools Setup. This is
explained in more detail in Tools on page 33.
Rad/Dia (Lathe mode only) ( ). You use this key is to toggle any axis
that you have defined as diameter (dia) in Setup mode, between radius
and diameter display on the screen. All axes that you defined as radius
(rad) in Setup mode are unaffected. When an axis is in diameter display
mode a small diameter symbol is shown against the axis value.
Preset ( ). You use this to enter the Preset or ‘Distance to go’ mode.
This is explained in more detail in Preset mode on page 17.
Half Function ( ). This is also known as Centerfind. You use this to
reduce the value of the selected axis by half.
The reference position is lost when you use this function.
Sub Datums ( ). You use this to enter the Sub Datum Function. This
is explained in more detail in Sub datums on page 36.

4
Introduction
Calculator ( ). You use this to enter the Calculator function. This is
explained in detail in Calculator on page 20.
Contrast up ( ). You use this to increase the contrast.
Contrast down ( ). You use this to decrease the contrast.
Probe ( ). You use this to execute the Probe function. This is explained in
detail in Probe function on page 28.
Setup ( ).You use thistoenter the Setup function.Thisisa protected
mode, so you need to enter a password to enter it. You use it to change
the DRO settings. This is explained in detail in Setup mode.
You use the left and right navigation keys to switch between different soft
key levels.
Other functions
Run ( ). Once you have configured the parameter values for an
operation, you run the operation by pressing .
Cancel ( ). You use this key to stop the current operation without
saving any changes.
Done ( ). You use this key to save and complete the data entry.
New ( ). You use this key to define a new job starting with the default
parameters for that particular function. If you choose to save the job later
then you can do so. The DP900 can save and recall up to 20 programs for
each major function.
Recall ( ). The DP900 can save and recall up to 20 programs for
each major function. For example, you can have 20 bolt hole circles, 20
grid arrays, 20 line holes, etc. This means that for repetitive jobs there is
no need to re-enter the data each time. Instead you canrecallthe jobfrom
a list. Pressing brings up a list of known job programs for that
function. You use the up and down navigation keys to highlight the
required job.
Delete ( ). You use this key to remove programs, jobs or tools that
you no longer require. When you press you are prompted for
confirmation: or . If you select , then the item is permanently
deleted and cannot be retrieved.
Save ( ). You press to save any changes you have made.
Copy ( ). If you need a new program that is similar to an existing
one then you can copy the original program, and then rename it. Use the
up and down navigation keys to find the program or job that you want to
copy. When the name of the existing program or job is highlighted, press
. This brings up the virtual keypad, so that you can enter a new
alpha-numeric name.
Rename ( ). If you need to rename a program or job, use the up and
down navigation keys to find the program or job that you want to rename.
When the name of the existing program or job is highlighted, press the
{rename} key. This brings up the virtual keypad, so that you can enter a
new alpha-numeric name.
D.Base. You use this key to open the DP900’s databases. Here you can
find information on tap sizes and clearance drills in both imperial and
metric formats.
Select ( ). You use this key on the alpha-numeric keypad to select
the highlighted character. You can also use the [arrow-centre] key.

5
Introduction
Upper ( ). You use this key on the alpha-numeric keypad to show
capital letters.
Lower ( ). You use this key on the alpha-numeric keypad to show
lower case letters.
Next ( ). You use this key to move to the next point or position.
Prev ( ). You use this key to move to the previous point or position.
Content ( ). You use this key in Help to return to the root Help menu.
Front panel dedicated keys
Sleep mode key
This temporarily turns off the display and keyboard. All other settings are
preserved. Encoder movement is still monitored while in sleep mode.
Press this key again to exit sleep mode. The LED on the front panel
flashes to indicate that the DRO is in sleep mode.
You can also select an integer value ranging from a minimum of 5 minutes
to a maximum of 120 minutes to select the sleep mode timer. The DRO
automatically goes into sleep mode if no operation is done during that
elapsed time.
abs/inc key
You use this key to toggle between Absolute mode and Incremental mode.
in/mm key
You use this key to toggle the display units between inches and
millimeters.
Ref key
You use the [ref] key to activate the Digifind feature, which you use to
recall a previously set reference (home) position. There are two types of
reference positions:
• Homing: This is the position that was most recently set in absolute
mode.
• Machine Reference (M/C Ref): This is the machine's permanent home
position. You set it up in Setup > Axis Settings > Machine Reference.
You should make a permanent mark on the machine when setting
reference points. If the axis has been moved while the DP900 power was
off, you can recall your reference positions using Digifind.
The display must be in absolute mode to use Digifind.
To use Digifind:
1. Press the [ref] key.
2. Set the axis close to the marked datum, to within:
6.3mm (0.25") for a Spherosyn encoder or
2.5mm (0.1") for a Microsyn encoder.
3. Select the {homing} or {M/C Ref} soft key.
4. The DP900 displays 'Select axis'.
Press the slider bar close to the respective axis.
The DP900 displays 'Referencing', and the axis you selected shows
'Homing' or 'M/C Reference'.

6
Introduction
5. Press the slider bar next to the respective axis again. The current
position is updated, and Digifind is complete.
Before you can use Digifind to find the Machine reference, you need to
define it in Setup mode > Select axis. The procedure is explained in
Setting the machine reference on page 18.
Alphanumeric keypad
You can give function programs and tools meaningful names. This means
that you can give names to items that have a direct relationship to the task
or tool. These could be company names, drawing numbers or customer
job references. You can use any combination of numbers, alphabetical
characters and some special characters, to a maximum of 12 characters.
When you need to enter an alphanumeric name the DP900 displays the
Data Entry screen showing all the available characters. You navigate
around these characters using the four navigation keys. Pressing
selects the highlighted character. If you enter the wrong character, you
can delete it by pressing the [ce] key.
Press to change the characters from a-z to A-Z and press
to change the characters from A-Z to a-z.
You can enter numbers directly using the numeric keypad.
Numeric keypad
This appears on the right hand side of the DRO. You use it to enter
numerical values. It also has a +/- key to enter positive and negative
numbers, and a decimal point key to enter decimal values. If you enter an
incorrect digit you can press the [ce] to delete each number in turn. If you
press the [ce] key when no numbers remain, the DRO stops the number
input operation. Press the [enter] key to confirm the number entry.
Navigation keys
The DP900 has four arrow keys that you use to navigate around the
screen. In this manual these are referred to as the navigation keys. These
keys are as follows:
• The left and right keys move you between the soft key pages when
there are multiple pages.
• The up and down arrows move you through pages of on-screen
information when there is more information than can be fitted on a
single screen.
• In graphical run-time modes, you use the up and down keys to select
the level of graphical zoom.
• When you are in conventional mode and operating a positioning
function such as Sub Datums, you use the up and down keys to move
between the next and previous datum or target points.
• In the middle of the four arrow keys is a circular key, this acts as an
enter key. It is referred to in the text as the [arrow-centre] key.

7
Specifications
Spec ification s
Encoder inputs
*TTL = 5V A quad B differential (RS422)
Mains supply 90…265V AC
50…60Hz
Fuse ratings T800mA
20mm length
Power consumption 20W
Operating temperature 0°C to 45°C
Storage temperature -20°C to 70°C
Relative humidity Max 85% non-condensing
Dimensions 280mm × 180mm × 75mm
(L × H × D)
Weight 1.9 Kg
Display 5.7" STN type monochrome LCD
Model Spherosyn/Microsyn** TTL*
DP900211000 X, Y —
DP90031110
DP90031110A X, Y, Z —
DP90041111A X, Y, Z, W —
DP9004111DA X, Y, Z W
Model Spherosyn/Microsyn** TTL*
A
A
B
B
R
R

8
Specifications
**Spherosyn/Microsyn: 2V, 1kHz, phase analog
360 degrees per ball pitch
Phase change of 90° relating to ¼ of a pitch or 1/8 inch (3.175 mm) for
Spherosyn.
Time
Phase
Shift
Signal Amplitude
Received
Signal
Transmitted
(drive) signal

9
Setup mode
Setup mode
This chapter describes how to setup the DP900.
Use the right navigation key to scroll through the soft keys until the Setup
soft key ( ) appears on the screen. Press the soft key to enter Setup
mode. This is a protected mode, so you need to enter a password to enter
it. PASSWORD 1 5 9 7 4 . Enter the number and then press the
[enter] key.
The Setup mode screen is displayed.
You navigate to the different fields using the up and down navigation keys.
The soft key labels display the options that you can select for each field.
You select a particular option by pressing the appropriate soft key.
General settings
No. of axis
You use this to set the total number of axes that you need to configure.
Select 2, 3 or 4 by pressing the appropriate soft key.
Sleep mode time (min)
You use this to define the Sleep Time Interval in minutes (5 to 120). Enter
the required time using the numeric keypad.
Key beep enable
You use this to enable or disable the keyboard beep. Select on or off by
pressing the appropriate soft key.
Zero app. beep en
You use this to enable or disable the Zero Approach Beep. Select on or off
by pressing the appropriate soft key.
When you enable the Zero Approach Beep, bars appear under the axis
numbers to clearly indicate the direction and relative position of the axis to
zero. As the beep starts the bars start to shrink towards the centre. The
bars disappear when the zero position is reached. The Zero Approach
Beep only beeps when you are within the set approach distance.
The beep rate gets faster as the zero position is approached. The beep is
only for the fastest moving axis.
Some functions like Preset have zero-approach always enabled.
Zero app. tolerance
You use this to set a tolerance value for the Zero Value in Zero approach
modes. Enter the required tolerance using the numeric keypad.
The value that you enter corresponds to the distance from zero that the
DRO considers to be close enough to zero to be counted as zero, i.e. the
point at which the beep becomes continuous (if enabled and so long as
the axis is moving) and when the zero-approach bars are clear.
Diagnostics
This enters a test mode where you can check the keyboard and any
attached encoders. Select keyboard or encoder by pressing the
appropriate soft key.
KBoard
Pressing {k board} shows a screen representing all the available keys.
Pressing a key highlights its position on the screen. To exit this test mode
press the [ce] key twice.
Encoder
Pressing {encoder} shows a screen with all the available axes displayed.
Here you can see the Axis, Count, Pitch, Type and Reference.

10
Setup mode
For Newall encoders the Type is 'N' and for RS422 encoders the type is
'Q'. Newall encoders provide a count that represents the absolute position
on the ball element within the scale in bits. (1-bit is 1/10000th of a ball
element). To exit this test mode press [ce].
Select axis
You use this to set the axis-specific parameters. Select X, Y, Z or W by
pressing the appropriate soft key. If you select W, then you first need to
select whether the axis is linear or angular.
Axis-specific settings (linear type)
Scale Type. You can set the X, Y, Z and W axes to be Spherosyn,
Microsyn 10 or Microsyn 5. The W-axis of a DP9004111DA model is an
RS422 TTL type encoder. For the X, Y and W axes, the default value is
Spherosyn and for the Z-axis, the default value is Microsyn 5. The
exception is the DP9004111DA model which does not have a scale type
parameter for the W-axis.
Scale Resolution. This option is available only for the W-axis of a
DP9004111DA model that you have configured as a linear type. You can
choose from 0.1µm, 0.2µm, 0.5µm, 1µm, 2µm, 5µm, 10µm, 20µm, and
50µm. The default value is 5µm.
Display Resolution. The resolution settings available for the X, Y, Z and
W axes are as follows:
The exception is the W-axis of a DP9004111DA model that you have set
to linear type, the resolution settings available are 0.1µm, 0.2µm, 0.5µm,
1µm, 2µm, 5µm, 10µm, 20µm and 50µm.
For the X, Y and W axes, the default value is 5µm. For the Z-axis, the
default value is 1µm.
Axis Direction. This parameter defines which reader head movement
direction results in a negative count. You can set the counting direction to
either left or right for each individual axis. The default value is left.
Axis Mode. You can set the Axis mode to either Radius or Diameter for
each individual axis. This is only valid if you have configured the DRO as
a Lathe model. For the Mill model, all the axes are forced to rad mode.
Machine Reference. Here you set the Machine reference for each
individual axis. Use Digifind to set the Machine reference. For the W-axis
of a DP9004111DA model, the encoder reference marker output is used
for referencing.
1. Press to enter the Machine reference mode.
The Homing message is shown on the display.
Resolution Display Spherosyn Microsyn 10 Microsyn 5
1 µm
(0.00005”) 1 — — x
2 µm
(0.0001”) 2——x
5 µm
(0.0002”) 5 xxx
10 µm
(0.0004”) 10xxx
20 µm
(0.001”) 20 x x —
50 µm
(0.002”) 50 x x —
Resolution Display Spherosyn Microsyn 10 Microsyn 5

11
Setup mode
2. Set the Absolute Datum using Digifind. Press the slider bar close to
the particular axis to set the datum. For the W-axis, the DRO goes to
the next screen automatically once it senses the reference output
from the encoder.
3. Bring the encoder near to the machine reference mark and press
. The new machine reference is set.
The default value for the machine reference is zero.
Zero App. Distance. This is the bar graph that is shown below the axis
display. It is available in all Distance to go modes. You can also force the
bar graph on using the Functions list. The value of this setting is the limit
for the bar graph. The default value is 1.000.
Calibrate Axis. You use this to compensate for errors arising due to wear
and tear, encoder misalignment, etc. You can calibrate each axis for
Linear Errors or Segmented Errors as applicable. The detailed procedure
for calibration is explained in Calibrate axis on page 14.
Apply Compensation. You use this to program the type ofcompensation
to be applied to the selected axis. There are three options: {none}, {l.
comp} and {s. comp}. The none option applies a linear calibration factor
of 1.0. The default compensation type is none.
Axis-specific settings (angular type)
This option is only available for the W-axis.
Counts per Revoln. This parameter defines the encoder counts per
rotation. You can enter this value if it is known or there is an automatic
calibration process for finding the CPR value. In the automatic process,
you are prompted to pass two reference marks in the same direction. The
DRO counts within them, and sets the CPR value. The default value is
4096.
Resolution (Deg.). This parameter defines the Display resolution in
degrees. The default value is 0.1 degrees.
Reference Mode. This defines which reference mode to select, Internal or
External. For Internal mode, the DRO uses the encoder reference mark
for referencing. For External mode, the DRO senses an external input
(Input 4) first and then references the DRO on the encoder internal
reference mark. You use this mode where one machine rotation
corresponds to more encoder rotations due to gear coupling. The default
is Internal.
Axis Direction. This defines the counting direction of the encoder,
clockwise (CW) or counter-clockwise (CCW). The default is CW.
Count Mode. There are two options:
Rollover: The angle rolls back to zero after 360.
Continuous: The angle continues accumulating after 360.
The default is Rollover.
Machine Reference. This is similar to the machine reference for the linear
type, except that the value is set in degrees.
Display Mode. The angular axis is configurable for two possible options.
DDMMSS. Degrees:Minutes:Seconds (00:00:00).
DDDEC. Decimal Degrees (0.0000).
The default value is DDMMSS.
Axis Lock. There are two options:
Axis Lock On
Axis Lock Off.
Axis Lock On stops you axis setting in Absolute mode. Only the operator
can perform referencing. The default value is Axis Lock Off.
Zero App. Angle. This is similar to the zero approach distance for the
linear mode, except that the setting is in angular mode. The default value
is 10.

12
Setup mode
Zero App. Tolerance. This is similar to the zero approach tolerance for
the linear mode, except that the setting is in angular mode. The default
value is 0.
You should save the changes that you make in the Setup mode using
Save and Exit.
The options for each menu item are displayed on the soft key label. You
have to press the correct soft key for the required settings.
Machine model
You use this to set the DRO to be Mill specific or Lathe specific, by
selecting mill or lathe using the appropriate soft key.
Auxiliary setup
You use this to set the parameters required for Auxiliary Input/Output
functions. See page 38 for details on using the auxiliary port.
Set factory settings
You use this to set all the DRO parameters to their factory defaults.
This option clearsall the programmed data including programs, SDM jobs
and segmented scale compensation.
To return to the factory defaults:
1. Press .
2. Press to confirm that you want to return to the factory default
settings.
If you decide that you don’t want to return to the factory default
settings, press .
The default setup settings are:
Applying compensation
You configure any compensation values in the Calibrate Axis setting.
Performing a Factory Reset clears any calculated compensation values
and the unit reverts to no compensation.
When you are measuring the values for compensating an axis, you must
ensure that you do not include the diameter of the probe or tool.
Error descriptions
Accuracy problems with machined parts may becaused by machine error,
DRO system error, or a combination of both. The first step in determining
No. of Axis 4
Sleep Mode Time 5
Key Beep Enable on
Zero App. Beep En. on
Zero App. Tolerance 0.025mm
Machine Model Mill
Axis Direction left
Axis Mode rad
Zero App. Distance 1.000mm
Apply Compensation none

13
Setup mode
the source of error is to check the DRO system. You do this by comparing
the movement of the Newall reader head to the position reading shown on
the display. You need a high accuracy standard, such as a laser
interferometer. You can use a dial indicator to check short distances, but a
laser provides the best results. If you have to use a dial indicator, be sure
it is the highest available accuracy.
To check the accuracy of the DRO system:
1. Place the targetof the laser or the needle of the dial indicator directly
on the Newall reader head.
It is absolutely critical that you take the readings directly from the
Newall reader head.
If you have to use a dial indicator, be sure that the needle of the
indicator is perpendicular to the reader head and not angled.
If you take readings anywhere else on the machine, machine errors
may distort the results.
2. When the reader head moves, the movement registers on the laser /
indicator and DRO display.
3. Set the laser / dial indicator and DRO display position displays to 0.
4. Make a series of movements and compare the position readings
between the laser / dial indicator and the DRO display.
If the readings match within the accuracy specificed, then you know
that the DRO system is operating properly. If this is the case, you can
proceed to the next step: evaluating the machine errors. If the
readings do not match, you must repair the DRO system before
proceeding with error compensation.
To evaluate machine errors:
1. Put the laser target / dial indicator on the part of the machine where
the machining is done.
2. Make a series of movements and compare the position readings
between the laser / dial indicator and the DRO display.
The difference between the laser / dial indicator reading and the
reading on the DRO display is your machine error.
3. Plotthe machine error along the entire axis of travel to determine the
nature of the error.
If it is a linear error, you can use linear error compensation. If the
error is not linear, you should use segmented error compensation.
When you are measuring the values for compensating an axis, you must
ensure that you do not include the diameter of the probe or tool.
There are many types of machine error, including pitch, roll, yaw, flatness,
straightness and Abbé error. The diagrams below demonstrate these
errors.
Way errors
Pitch
Axis
Yaw
Axis
Typical Yaw
Deviation Straightness
Roll Axis
Travel
Flatness
Typical Pitch
Deviation

14
Setup mode
Abbé error
Calibrate axis
Calibration parameters are found under Setup mode > Select axis. There
are two options:
• Calibrate axis
• Apply Compensation
The Calibrate axis menu offers two modes of compensation:
• Linear Compensation {l.comp}.
• Segmented Compensation {s.comp}.
If you set the axis to Segmented Error Compensation, or Linear Error
Compensation, then your next set up option is to configure the
compensation for that axis.
If you apply Error Compensation, then you must ensure that it is
absolutely correct. If it is not correct, then errors could be increased rather
than reduced.
Once you have set up the ErrorCompensation, weadvise you to check its
effect in normal operation.
Linear compensation
A linear error occurs between the measuring device and the part to be
measured, if the axis is not truly parallel with the encoder scale axis. You
can overcome this by applying a scaler to the measured axis value before
it is displayed. You calculate the correction factor, and specify it in parts
per million (ppm). The values can be between -9999 and +9999.
The DP900 hasanautomatic facility tocalculate the linear error correction
scalar.
All displayed values are in mm, regardless of whether the DP900 is set to
inch or mm mode.
1. Move to the start position.
2. Zero the display value by pressing {reset}.
3. Move a known distance (use a laser interferometer, slip gauge or
standard).
4. Select 'Slip Value' and enter this known distance using the numeric
keypad.
5. Select 'Cal Factor' and press {calc}.
The DP900 calculates and displays a scalar compensation value.
A
B
C2
C2
B2
A2
B1
C1
B1
A1
C1
A1
greater than
End Effector Linear
encoder
Encoder
End Effector Linear
encoder
Encoder
less than
encoder
Shown with encoder on concave side of
bearing path Shown with encoder on convex side of
bearing path
Error
Travel

15
Setup mode
Before you can apply this compensation factor, you must enable it. Go to
Setup mode > Select axis > Apply compensation, then select {l. comp} or
{s.comp}.
When you are measuring the values for compensating an axis, you must
ensure that you do not include the diameter of the probe or tool.
Segmented compensation
On the DP900 each axis can have up to 50 segments of compensation.
Compensation is provided linearly between the segment points.
The values for segmented error compensation are calculated using a
simple semi-automated procedure.
When you select segmented compensation, you can select {auto} or
{edit} to set up the compensation.
If the machine has not been moved since the power was turned off, press
the [ce] key, and the DP900 restores the last positions that were recorded.
Alternatively, you can set each axis close to the Reference Point, to within:
6.3mm (0.25”) for a Spherosyn encoder or 2.5mm (0.1”) for a Microsyn
encoder, and press the slider bar close to the ‘X’, ‘Y’ or ‘Z’ axis. The
DP900 re-establishes alignment with the correction parameters.
You need not apply Segmented Compensation over the entire scale
length. You can apply it to a length of high importance, or to just one
segment.
If you set one or more axes to Segmented Error Compensation, then you
need to carry out the following procedure to configure the compensation
for each of those axes.
When you are measuring the values for compensating an axis, you must
ensure that you do not include the diameter of the probe or tool.
Identifying the correction parameters
The scale travel is broken down into a number of segments that you
define, each with its own correction factor, measured against a high-
accuracy standard. You need to identify the following parameters:
You measure each Correction Point with respect to the Starting Point,
zero. You usually set this close to one end of the scale. You can set the
Reference Point anywhere along the scale. It does not need to coincide
with either the absolute datum or any of the correction points. However,
you may find it convenient to make the absolute datum and the reference
point the same.
Setting the correction points
As you follow the procedure you must ensure that you always approach
the Starting Point, Correction Points and Reference Point from the same
direction. If you do not, then the size of the tool or probe renders the
measurement inaccurate.
Auto
1. Go to Setup > Select Axis > Apply Compensation and set this
parameter to {s. comp}.
2. Go to Setup > Select axis > Calibrate axis and select {s. comp}.
Error
0
Starting point - zero
16
2
3
45
Travel
Machine reference point Correction points

16
Setup mode
3. Press {auto}.
The message ‘Homing...’ appears on the screen, and the DP900
automatically finds the Starting Point.
4. Press the slider bar next to the axis you are calibrating.
The message ‘Set MC Ref.’ appears on the screen.
5. Press {Set} to set the MC Ref.
The DP900 displays the Observed Value (linear encoder position)
and True Value (laser interferometer position) for the first segment.
Move the axis to the end of the first segment. The observed value is
updated to reflect this movement.
6. Use the down navigation key to select the True Value, and enter the
value shown on the laser interferometer.
7. When you press the [enter] key the compensation value iscalculated
and displayed.
8. Use to move to the next segment.
9. Repeat the procedure for each segment.
10. Press to save the valuesand leave the Calibrate Axis set
up.
11. Press to leave the Calibrate Axis set up without saving the
values.
Edit
1. Set the axis to Segmented Compensation as described in Calibrate
axis on page 14.
2. Press {edit}.
3. Use the and to move to the segment number that you want
to edit.
4. Press {edit}.
5. Enter a value for the Observed Value.
6. Enter a value for the True Value.
7. Press or to return to the previous screen.
8. Repeat the procedure for all the segments.
9. When you have entered values for all the segments, press to
save your entries and leave the Calibrate Axis setup.
You can define up to 99 segments per axis.
To use Segmented Error Compensation, you need to have a high
accuracy standard, such as a laser interferometer system.
Segmented Error Compensation initially defaults to Off, with no points set.
If you set Apply Compensation to none after you have set the Correction
Points, then the data is retained, but not applied. When you next set Apply
Compensation to s.comp, the data is re-applied.
You must carry out this procedure in strict sequence, and in full, for it to be
valid.
Do not worry about the direction of the standard measurement. For
example, 678.9 and -678.9 are treated the same.
You can press the [ce] key to clear an entry.

17
Basic functions
Basic functions
This chapter describes the basic functions of the DP900.
The basic functions are as follows:
• Absolute mode
• Incremental mode
• Inch and mm
• Loading an axis
• Preset mode
• Referencing
• Graphical zoom
• Calculator
Absolute mode
In Absolute mode the DRO displays the positions of all the axes with
respect to a fixed datum. The datum is set by entering an axis position
when in Absolute mode. The current display mode is shown in the
Information bar (see Information bar on page 3 for further details). You
switch between Absolute mode and Incremental mode by pressing the
[abs/inc] key.
Incremental mode
In Incremental mode the DRO displays the position relative to the last
position. This is also known as point-to-point use. In this mode you can set
the value for each axis, or zero it to create an Incremental datum. This
does not affect the machine’s Absolute datum that you configure in
Absolute mode. The current display mode is shown in the Information bar
(see Information bar on page 3 for further details). You switch between
Absolute mode and Incremental mode by pressing the [abs/inc] key.
Inch and mm
The DP900 has a dedicated key (the [inch/mm] key) to switch the
positional displays between imperial (inch) and metric (mm)
measurements. The current display mode is shown at the top left of the
screen as either mm or in.
Loading an axis
In normal operation, with the axis values on the screen, you can select the
mode of axis data operation by pressing . This toggles the axis mode
legend between 'SET' and 'ZER'.
When you select 'ZER', pressing the slider bar next to the axis legend sets
that axis value to zero.
When you select 'SET', pressing the slider bar next to the axis legend
changes its value to '0'. You can then enter a number using the numeric
keys. Pressing the [enter] key loads this value in to the axis. Pressing the
[ce] key deletes the value that you entered and restores the original value.
Preset mode
The Preset function provides a simple mechanism for stepping through
repeat positions using the work-to-zero principle. It also takes into account
positioning errors for repeated points.
The first time that you enter the function, the previous move error is set to
zero. In this way pressing only recalls any previous axis preset
value.
Axis preset values are not maintained after a power cycle.
The setting of the axis preset value does take into account the error of any
previous move. The value that you enter is the step move value.