ACU-RITE DRO 200M User Manual

DRO 200M

™

REFERENCE MANUAL

Readout Parameter Access Code

An access code must be entered before machine-related parameters can be set or
changed. This prevents inadvertent adjustments to the setup parameters.

IMPORTANT

The access code is 8891

Refer to the Setup section. Begin by pressing the

9

displayed, press the 8, 8,
ready for machine parameter setting operations.

,

1

, and

SETUP

key. When “SETUP” is

ENTER

keys. The readout is now

IMPORTANT

Supervisors may wish to remove this page from the Reference manual
after initially setting up the readout system. Retain in a safe place
for future use.

Warranty

ACU-RITE Products and accessories are warranted against defects
in material and workmanship for a period of three years from the
date of purchase. ACU-RITE will, at its option and expense, repair
or replace any part of the ACU-RITE product that fails to meet this
warranty. 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 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. ACU-RITE
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 INCORPORATED shall not be liable
under any circumstances for consequential damages.

30 Day Red Carpet Warranty

All ACU-RITE products are covered by a 30-day Red Carpet
Warranty. If in the first 30 days this product fails for any reason,
repack it in the original packing materials and contact your
Authorized ACU-RITE Distributor for return procedures.

DRO 200M Table of Contents

Introduction ........................................................................................................1

A Tour of the Readout..................................................................................................1

Front and Back Views...............................................................................................1

Keypad .....................................................................................................................2

Displays....................................................................................................................3

Power-On Position Recovery......................................................................................4

Position-Trac ............................................................................................................4

Readout Operations..........................................................................................5

Clear Key.......................................................................................................................5

Absolute and Incremental Displays............................................................................5

Absolute Display.......................................................................................................5

Incremental Display..................................................................................................5

Zeroing the Displays ....................................................................................................6

Absolute Zero...........................................................................................................6

Moving the Absolute Zero.........................................................................................8

Zeroing at a Center Line...........................................................................................9

Incremental Zero.......................................................................................................9

Presetting....................................................................................................................10

Absolute and Incremental Presets..........................................................................11

Center-line Presets.................................................................................................12

Near Zero Warning .....................................................................................................13

Centerlines..................................................................................................................13

Bolt Hole Patterns ......................................................................................................14

Defining the Bolt Hole Pattern.................................................................................14

Using the Result.....................................................................................................15

Tool Offset...................................................................................................................16

Defining the Offset Direction...................................................................................16

Using Tool Offsets..................................................................................................17

Setup..................................................................................................................18

Machine-Related Setup Parameters .........................................................................18

Count Direction.......................................................................................................18

Tool Offset Direction...............................................................................................18

Encoder Resolution................................................................................................18

Job Setup Parameters................................................................................................19

Display Resolution..................................................................................................19

Scale Factor ...........................................................................................................19

Near Zero Warning.................................................................................................19

Bolt Circle Definition................................................................................................20

Linear Error Compensation.....................................................................................20

Edge Finder Diameter.............................................................................................21

Installation.........................................................................................................22

Readout Specifications...................................................................................25

Troubleshooting ..............................................................................................26

!

This symbol alerts you to the fact that
important information concerning the
installation and operation of this readout
has been included in this manual.

DRO 200M

Keep these instructions in a secure place
for future reference.

DRO 200M Introduction

Electronic

Input

Encoder

Model number and

Electrical &

information

Power switch and

Ground wire

Indicators

Application-specific

Introduction

ACU-RITE’s DRO 200 readout series provides application-specific features
required for you to obtain the most productivity from your manual machine tools.

The DRO 200M is designed specifically for milling and drilling applications. Special
features include an easy to use bolt hole routine, centerline locating, and quick
tool offsetting.

A Tour of the Readout

Front and Back Views

fuse rating

MM INCR ABS ZERO SET C/L

FREQUENCY

VOLTAGE
CURRENT
FUSE

115V

!

ABS
INCR

ZERO

X

C

TOOL

DIA

ZERO

Y

Z

ZERO

BOLT

CIRCLE

DEFINE

USE

SETUP

MM

7 9

8

4 6

5

1

2

..0 +/-

CLEAR

ENTER

3

function keys

FCC COMPLIANCE

Edge
Finder

EDGE

FINDER

INPUT 1INPUT 2INPUT 3

inputs

voltage selector

connection

3x DRO
PN 2001009
SN 9766554

Serial number

1

Introduction DRO 200M

Use these to define a

Zero an axis display

Begin a preset

Compensate for tool

Keypad

Selects absolute or

incremental display

Used to locate

centerlines

diameter

X

Y

Z

ABS

INCR

C

TOOL

DIA

ZERO

ZERO

ZERO

English / metric

conversion

Enter all numeric values

with these

BOLT

CIRCLE

DEFINE

MM

SETUP

. 0

CLEAR

System setup
parameters

87 9
54 6
21

3

+/-

ENTER

USE

bolt hole pattern, and

use the calculated

hole positions.

2

DRO 200M Introduction

Displays

At the top of the display window is a row of indicators. These tell you the current
state of the readout.

MM INCR ABS ZERO SET C/L

Appears when

setting an

absolute zero.

Appears when you’re

positioning in metric,

dark when you’re

positioning in inches.

Lets you know when

you are setting a

preset or an absolute

zero.

These tell you if the

position display is

incremental or absolute.

They also refer to the

type of preset.

Tells you when
the centerline

function is active.

In addition to the lighted indicators along the top of the display, the top axis
display will scroll longer messages that will help you step through some of the
procedures.

3

Introduction DRO 200M

Power-On Position Recovery

Position-Trac

Certain ACU-RITE encoders, such as the ENC 150, contain closely spaced
reference marks that enable the display to show the correct position after a power
interruption. The readout will indicate when power has been lost, and will prompt
you to move each axis until a reference mark is located. By traversing the
reference marks once in each axis, you will re-establish the display position
relative to the last known zero. The most you will ever have to move an axis is
about one inch. You must move in a positive count direction. A flashing decimal
point will indicate that the last position has not been recalled.

If you use an encoder without Position-Trac, the procedure for recovering your
position is slightly different. Reference marks on these encoders are about 8”
apart. You must find a convenient reference mark and then use the same mark
every time.

1. Move near the desired reference mark.

2. Press and hold the

3. Move slowly past the reference mark until the readout recalls its position.

ABS

key until the decimal point starts to flash.

INCR

You must move in a positive count direction.

4

DRO 200M Readout Operations

Readout Operations

Clear Key

Use the

CLEAR

key to erase digits that you entered by mistake, or to take you back if

you’ve pressed a wrong function key.

Absolute and Incremental Displays

Absolute Display

Shows the distance from your current position to absolute zero.

The drill is positioned at

1.625 ABS.Absolute Zero,

also called datum

or Workpiece

Zero

1.625

X 1.625 ABS

Incremental Display

Shows the distance from your current position to incremental zero. An incremental
zero is set when you preset a dimension, or when you zero the incremental
display.

The drill is 0.625 on
the negative side of
the incremental zero.

Absolute

zero.

1.000

-0.625

1.625

X -0.625 INCR

ABS

INCR

X 1.000 ABS

Incremental zero: the
incremental display
will read 0.000 when
the drill is here.

Automatic Display Switching

Sometimes the readout will switch from one display to the other automatically.
When you enter a preset, for example, the display switches to the incremental
display so that you can move to zero. Whenever the readout does an automatic
display switch, INCR will appear briefly in the display.

5

Readout Operations DRO 200M

2.44

You don’t have to worry about

Shortcut

Zeroing the Displays

Absolute Zero

On many prints, dimensions are measured from
one or two surfaces of the workpiece. By setting
the readout’s absolute display to zero at a well­chosen surface, you can enter the
part’s dimensions directly from the
print, using absolute presets.

Setting Absolute Zero at the Current Position

1. Move to desired location.

2. Make sure that the absolute position is displayed.

Absolute zero

0.72

1.44

ABS

INCR

3. Zero the appropriate axis.

Setting Absolute Zero Using an Electronic Edge Finder

1. Install the edge finder into the spindle and connect it to the readout.

2. Make sure that the absolute position is displayed.

3. Press the

ZERO

key for the appropriate axis.

4. Move slowly until the edge finder touches the edge

of the workpiece. The absolute position display
will automatically be set to zero at the workpiece
edge.

overtraveling because the edge

finder probe shaft is flexible. The

readout will zero on contact.

ZERO

ENTER

ZERO ZERO

ABS

INCR

ZERO

6

DRO 200M Readout Operations

You will have

Shortcut

Setting Absolute Zero with a Tool

1. Touch the tool to the edge of the workpiece.

2. Make sure that the absolute position is displayed.

3. Press the

ZERO

key for the appropriate axis.

4. Enter the position of the tool center.

+/- . 2 5

1

Setting Absolute Zero Using a Tool Offset

1. Enter the tool’s diameter.

TOOL

DIA

. 2 5

0.25

-.125

ENTER

better results
if you mill a
new edge.

ABS

INCR

ZERO

ENTER

2. Make sure that the absolute position is displayed.

3. Identify the right edge of the tool.

6

ABS

INCR

4. Touch the tool to the X=0 edge of the workpiece and press the

the appropriate axis.

ZERO

ENTER

ZERO ZERO

7

ZERO

key for

Readout Operations DRO 200M

Moving the Absolute Zero

Sometimes you may need to move the absolute zero from its original position on
the workpiece to a different position.

Absolute zero

is currently

here...

1.625

X 0.0000

1. Move the tool to absolute zero.

2. Press the

ZERO

key of the appropriate axis and enter the new tool position,

from the new absolute zero.

+/- 2 5

1.625

X -1.625

...but you
want it to
be here.

6.1

Now zero is here,
and the tool position
is -1.625

ENTER

8

DRO 200M Readout Operations

Zeroing at a Center Line

Begin setting absolute zero in the usual way and then tell the readout that you
want to use the centerline feature.

ABS

INCR

ZERO

C

Touch the first edge…

ENTER

…then the second edge.

ENTER

The absolute zero is placed mid-way between the two edges.

Incremental Zero

From the incremental display, press the
display to zero at the current tool position.

ZERO

key. This sets the incremental

9

Readout Operations DRO 200M

Presetting

When you preset a dimension, the readout places an incremental zero at the
location you specify. Then the display automatically switches to the incremental
display so that you can move to zero.

Begin a preset by pressing an axis key (X for example). The information of the
previous preset will appear. The display will show you if the preset is absolute or

incremental. Use the

Absolute

zero.

X 0.000 ABS

ABS

key to toggle between them.

INCR

1.625

Preset the absolute location of the hole.

The drill is positioned at

0.000 ABS.

X 2 5

-1.625

1.625

X -1.625 INCR

ABS

INCR

X 0.000 ABS

6.1

ENTER

Now the drill is 1.625
on the negative side
of the hole.

Incremental zero: the
incremental display
will read 0.000 when
the drill is positioned
over the hole.

10

DRO 200M Readout Operations

When you enter an incremental preset, the

When you enter an absolute preset, it does

Absolute and Incremental Presets

To maintain the best tolerance and to minimize the chance for errors, use

• absolute presets for absolute dimensions

• incremental presets for incremental dimensions.

Absolute

Incremental

0.72

1.44

Incremental

not matter where the tool position is. The
DRO 200M calculates the desired location
automatically.

2.44

ABS

X

INCR

X

. 7 2

1

.X 4

2 . 4 4

tool must be positioned at the location you are
dimensioning from.

ABS

INCR

. 5 0

1 . 0

X

X

0.50

0.72

1.00

.

4

7

.X 2

ENTER

ENTER

ENTER

ENTER

ENTER

ENTER

11

Readout Operations DRO 200M

Move to the first edge…

…then to the second edge

Center-line Presets

You can set a preset at the center of a workpiece, or in the center of a hole.

incremental zero

Sets an

at the tool

location.

Calculates the

center, and sets an

incremental zero in

the middle.

X

2.0

ENTER

ENTER

C

X 0.000 INCR

X 2.250 INCR

X 1.125 INCR

12

DRO 200M Readout Operations

Near Zero Warning

When you are moving to zero, the readout can “warn” you when you are getting
close. This allows you to machine faster and avoid overshooting your desired
location.

You can set the near zero range in Setup.

Near zero range.

The digits displayed to

the left of the decimal

point will flash.

Centerlines

You will normally use the centerline function when you are doing a preset, to put
an incremental zero at a centerline, or when you want to set the absolute zero at a
centerline. Refer to page 12 for presetting to a centerline, and page 9 for setting
absolute zero on a centerline.

At any other time, using the centerline function will divide the current position in
half and display the result in the incremental display.

C

Divides the X axis

X

display in half.

13

Readout Operations DRO 200M

Always enter the center

For a full circle with the first hole at

Y

This 8-hole bolt hole

Bolt Hole Patterns

Calculating hole locations in a bolt hole pattern is a two-step process: defining the
bolt hole pattern and using the results.

Y

0.625 Radius

Defining the Bolt Hole Pattern

Press the
prompt you to enter information about

the bolt hole pattern.

DEFINE

key. The readout will

0.875

8 THRU
HOLES 0.125
DIA

Number of holes:

The maximum number

ENTER

8

1.000

of holes is 99.

Circle center, X-axis:

Circle center, Y-axis:

Circle radius:

Starting angle of the first hole:

0.1

7 5

8.

2 5

6.

ENTER

ENTER

0

ENTER

ENTER

the 3 o’clock position, like the

Ending angle of the last hole:

ENTER

example above, both the start angle
and end angle can be left blank.

You can review the bolt hole pattern definition by pressing
through the parameters with the

ENTER

key.

X

Center,
measured from
Absolute Zero

of the circle as a
dimension from absolute
zero.

DEFINE

and cycling

If the bolt hole pattern is rotated from the 3 o’clock position, enter the start angle.

+30°

X

Leave the end angle
blank for a full (360º)
pattern.

14

pattern starts at 30º.

DRO 200M Readout Operations

This 5-hole bolt hole

For partial bolt hole patterns, you need to enter an end angle.

Y

210°

30°

X

pattern starts at 30º, and
ends at 210º.

Using the Result

After you have defined the bolt hole pattern, press the
results. Each time you press

USE

, the readout displays the hole number briefly,

then presets the X and Y location for that hole. All you have to do is move to zero
and drill the hole.

Y

3

4

5

6

7

2

USE

key to use the

1

X

8

The readout will remember the hole pattern until you change it. This means that
you can return to any of the holes at any time—just press

If you need to go to a specific hole, just enter its number after the

USE

15

USE

.

USE

key.

ENTER

5

Readout Operations DRO 200M

Tool Offset

If you enter the diameter of the cutting tool you are using, you don’t have to add
or subtract the tool’s radius when you enter a preset. Just select which edge of the
tool you want to compensate for, and the DRO 200M automatically adds or
subtracts the tool’s radius.

Defining the Offset Direction

The symbols on the number keys indicate the offset directions—they represent a
top view of the tool and the part edge.

Tool Back

Edge

8

Tool Left

Edge

2

Tool Front

Edge

Tool Right

654

Edge

Tool Center

Whenever the readout is displaying an absolute or incremental position, the
number keys can be used for tool offset compensation. Just press the key
corresponding to the edge of the tool whose position you want to display.

2

8

4

Inside...

6

2

...and outside

46

8

16

DRO 200M Readout Operations

To check your tool compensation before

return to the position display.

If the right edge is at absolute zero-

Using Tool Offsets

First enter the tool diameter.

TOOL

DIA

. 5 0 0

ENTER

Then select the edge you want to use for the axis you want to move.

6

Right edge

5

Center

Always use

this when

drilling.

X 0.000 ABS

Left edge

X -0.250 ABS

X -0.500 ABS

4

While you are moving, the readout display will indicate if a tool is being
compensated for.

Left

edge

Right

edge

you move, press

Front

edge

TOOL

DIA

. Press it again to

17

Back
edge

Setup DRO 200M

Setup

SETUP

The
are job related, meaning that they may change from job to job. Others are
machine related and should be set as part of the installation. The machine-related

parameters can be accessed by pressing:

key lets you change the system parameters. Some of these parameters

SETUP

Access Code

ENTER

Use the X key to move from one parameter to the next. After the last
parameter, the X key ends the setup process and saves any changes. Use the

CLEAR

key to move back to a previous parameter.

Some parameters have choices. Use the Y key to cycle through the available
choices.

At any time during setup, pressing the

SETUP

key will end the setup process and

save the changes.

Machine-Related Setup Parameters

Count Direction

This determines which way is positive. Move each axis in the positive count
direction. The display will show a 1 or a 2 depending on count direction. You can

also change the count direction by pressing the Y key.

Tool Offset Direction

Move each axis in the direction that will make the tool
edge contact a workpiece as shown here. The display
will show a 1 or a 2 depending on offset direction. You

can also change directions by pressing the

Y

key.

Encoder Resolution

Move each encoder until the readout senses and
displays the resolution. You won’t have to move more than two inches. For
encoders without Position-Trac, you need to enter the scale resolution. You can

press the Y key to select from common choices, or you can use the keypad to
enter the resolution directly.

18

DRO 200M Setup

For a scale factor that allows for 3% material shrinkage, use this formula:

.971.03

1

1

Job Setup Parameters

Display Resolution

The display resolution will be the same as the encoder resolution. If the job
tolerance is coarser than the encoder resolution (±0.005 for example), you can
adjust the display resolution so you won’t be tempted to waste time by machining

to a finer resolution. Use the Y key to cycle through all the possible choices. The
choices available depend upon the resolutions of the scales.

Scale Factor

You can define a scale factor for each axis. The typical scale factor is 1.000, which
means that the displayed dimensions are the actual part dimensions. A scale
factor less than 1 causes the part to be smaller than the print dimensions; a scale
factor greater than 1 causes the part to be larger.

1.0309

3 0 9.1

ENTER

Enter the factor by pressing

rScaleFacto ==

=

−

0

Additionally, a scale factor of –1.00 will produce a mirror image of the part. You
can both mirror and scale a part at the same time.

0.50

0.50

1.50

0.50

1.75 0.50

Print

Resulting part with

X scale factor = -1
Y scale factor = +1

Near Zero Warning

Each axis has its own near zero range. You can activate or deactivate the near
zero warning feature by pressing the Y key. When the warning is activated,

you can enter the range. Refer to page 13.

19

Setup DRO 200M

Bolt Circle Definition

You can define the size of a bolt hole circle either by its radius or by its diameter.
Use the Y key to toggle between radius and diameter.

Linear Error Compensation

The DRO 200M includes a linear error

Segment 2Segment 1 Segment 3

compensation feature that enables you to
compensate for machine tool
inaccuracies.

Machine table front view

(slightly exaggerated)

You can have up to three different
compensation segments per axis. You will need either a dial indicator or an edge
finder, along with a measurement standard.

1. Enter the number of intervals you will use. If you do not want to use any

error correction, enter 0. Press

2. Position the standard in the center of the first segment.

3. Press

4. Enter one edge of the standard.

5. Enter the other edge of the standard.

Y

ENTER

X

to start the first interval.

ENTER

6. Enter the actual size of the standard, including the probe diameter if

necessary.

If the display shows
all dashes, refer to
“Display Overflow
Errors” on page 30.

8.1250

Opposite sides

8.0000

Same side

20

DRO 200M Setup

7. Press

X

for the next segment or, if all segments are done, the next axis.

Edge Finder Diameter

Enter the diameter of your electronic edge finder. You can use the MM key to
select between English and metric units, depending on your edge finder.

21

Installation DRO 200M

IMPORTANT

Installation

Before installing the DRO 200M readout, record the serial
number on the warranty card and return it to ACU-RITE
INCORPORATED. The serial number label is located on the
back of the readout.

Selecting a Location

Selecting a location for the readout is an important consideration for proper
installation. Keep the following points in mind when selecting a safe and
convenient location:

• The readout should be within reach of the operator for easy access to the

keypad.

• The readout should be approximately at eye level.

• Avoid moving components or tools and minimize coolant splash or spray.

• The operating environment must be within the temperature range of 0° to

40°C (32° to 104°F) with a non-condensing relative humidity of 25% to 85%.

Proper Mounting

ACU-RITE has developed special mounting kits for the readout, which address
the most common mounting requirements. Mounting kits include:

• Column and base machine mountings

• Hardware and mounting instructions

These kits are available from your factory authorized ACU-RITE Distributor or
OEM/OEI.

If you fabricate a support device for the readout, it should be large enough and
strong enough to accommodate the readout. It must also be stiff enough to
minimize any vibration induced by machinery on the shop floor.

22

DRO 200M Installation

Connecting the Encoders

Insert the connector from each encoder into the mating connector on the back of
the readout. Fasten it with a small screwdriver.

Encoder input 1 will be displayed in the readout’s top display, input 2 in the next
display, and input 3, if any, in the bottom display.

Provide enough slack in the encoder cables to allow for full travel of all machine
axes. Check that machine movements will not pinch the cables. Use the cable tie­down hardware kits supplied with the encoders to fasten the cables neatly to the
machine.

Connecting a Ground Wire

Connect a ground wire from the terminal on the back of the readout to the
machine. The machine should also be connected to a solid earth ground. If not, be
sure that the readout is.

23

Installation DRO 200M

Checking Voltage and Connecting Power

!

CAUTION

Connecting the readout to a power source outside of the
acceptable range, or making an inappropriate setting with the
voltage selector, may damage the readout, the encoders, or
both.

Check that the voltage available at the power source is within specification before
connecting it to the readout. If required, set the voltage selector to match the line
voltage.

Opening

slot

1. Remove the caution label from the input module, and

use a thin-blade screwdriver in the slot at the top of the
power-input module to open the module cover.

2. Pull the selection block out.

3. Remove the fuse, move the shorting bar to the

other side, install the correct fuse, and push
the block back into place.

4. Close and snap the cover shut.

The voltage setting will show through the window in the voltage selector cover.
Connect the readout to the power source using the power cord supplied.

24

DRO 200M Readout Specifications

Readout Specifications

Characteristic Specification

Operating conditions 0° to 40°C (32° to 104°F)

25% to 85% relative humidity (non-condensing)

Storage conditions

Input requirements
Voltage:
Frequency:
Current:
Fuse 115V operation: ½ A, 250V, 3AG, Slo-blo

Encoder input

Edge finder input Compatible with ACU-RITE electronic edge finder
Size 12.5”W x 5.125”D x 6.5H”

-40° to 60°C (-40° to 140°F)
25% to 95% relative humidity (non-condensing)

115VAC or 230VAC (+/-20%), single phase
47-63 Hz
300ma @115V, 150ma @230V

230V operation: ¼ A, 250V, 3AG, Slo-blo
Position signals: channels A & B

TTL square wave signal in quadrature
(90° nominal phase relationship)
Maximum input rate: 50 kHz

Reference signal: TTL square wave

Weight 7.5 lbs.
Mounting Bottom: two ¼ -20 threaded inserts
FCC compliance Class A

25

Troubleshooting DRO 200M

NOTICE

Troubleshooting

This section is intended to provide you with some basic troubleshooting assistance
with your readout system. If you cannot correct the problem after following these
instructions, contact your authorized ACU-RITE distributor or OEM/OEI for
repair or replacement procedures.

No Operation

If you turn power off, you must wait at least 5 seconds before
turning it back on, or the readout may not power up. This is
because the power supply, in order to withstand brief power
outages and brownouts, requires several seconds to reset
itself.

If the readout display will not operate, check the following conditions:

• Check AC power source. If the readout cannot be powered up,

line voltage is present at the source and that the line voltage meets the
required specifications.

• Check power cord. Remove the power cord at the electrical input module on

the back of the readout. Determine if line voltage is present at this end of the
cord.

• Check fuse. With the power cord removed, use a thin straight-blade

screwdriver to remove the cover of the electrical input module. Refer to page

24. Slide out the fuse holder and check the fuse. If necessary, replace it.
Replace the input module cover by snapping it back into place, and reconnect
the power cord.

!

Replace fuses only with the specified type. Using incorrect
fuses can present a safety hazard. The readout may also be
permanently damaged. Refer to the Readout Specification
chart on page 25 for the correct fuse.

CAUTION

confirm that

26

DRO 200M Troubleshooting

Incorrect Operation

If system positioning does not seem to be repeatable, the problem could be with
the machine tool or with the readout system.

• Check the machine tool. Check that the table is not locked. Ensure that the

knee, ram, head bolts, turret-to-column bolts, and head-to-knuckle bolts are
properly secured. Check the gib adjustments. Tram the head. Check spindle
run-out.

• Check linear encoders. Check each encoder and reading head for proper

installation. Ensure that the mounting brackets are secure.

If the system seems to be displaying incorrect positions, check the following items.

• Verify presets. Make sure the numbers you enter are correct.

• Verify tool. Check that the correct tool number is being used. Make sure the

tool diameter has been entered correctly. Measure the tool diameter to check
for tool wear.

• Verify the scale factor. Ensure that the correct scale factor is being used.

• Verify linear error compensation. Make sure that the factors used for linear

error compensation are correct.

Power-On Self Test

There are four tests performed when power is applied to the readout. You will not
notice these tests unless a problem is found, in which case a message will scroll
across the display.

Keypad—a key was detected stuck down. The message will display what row (x)
and column (y) the stuck key is in:

KEY STUCK – RxCy – PRESS CLEAR

Parameter memory—some of the system setup parameters are not valid. You
may be able to check and reset these settings, but it’s possible they will be lost
again. The readout should be serviced as soon as possible.

MEMORY FAILURE [1] – PRESS CLEAR

!

Some working settings are not valid. Proceed with caution.

CAUTION

27

Troubleshooting DRO 200M

Working memory—the memory used by the readout for calculations is faulty.
While it may be possible to use the readout, it’s position display and other
information will not be reliable.

MEMORY FAILURE [2] – PRESS CLEAR

!

CAUTION

The readout cannot be relied on for correct operation if any
memory failure is indicated. The readout should be serviced
immediately.

Program memory—the memory used to store the software is faulty. While it
may be possible to operate the readout, some functions will not work properly and
wrong information can be displayed.

MEMORY FAILURE [3] – PRESS CLEAR

!

CAUTION

The readout cannot be relied on for correct operation if any
memory failure is indicated. The readout should be serviced
immediately.

Internal Testing

Several internal tests may be performed to ensure that the readout is functioning
properly. Tests are available for the internal memory, the keypad, and the
display. In addition, the testing procedure reports the software version of the
readout.

28

.

key for about 2 seconds.

Begin the internal testing by holding down the
The software version will appear in the X-axis display

DRO 200M Troubleshooting

Keypad test. Begin by pressing the X key, then press each key (except the

X

key) in turn to verify that it is functioning properly. When a key is pressed,

the X-axis activates a “plus sign” indicator and increments a count. When you
release the key, the plus sign disappears.

Display test. Begin by pressing the X key. All indicators in all displays will
light. Visually check each portion of each display to ensure that they are

functioning properly.

Press X again to test the display electronics. All decimal points on all displays
will light momentarily, then each segment of all displays will light in turn. Press

X

again, and each digit of all displays will light, one digit at a time, starting

with the leftmost digit and moving to the right.

Exit the diagnostics by pressing the X key.

Other Errors

The readout includes built-in test and error-checking circuitry. This circuitry
identifies errors that occur, and reports the problem to the operator. Errors are
reported by scrolling messages in the X-axis display.

Loss of power is indicated by the “Power was off” message. Loss of power means
that power to the readout has been interrupted. Since power to the encoders has
also been interrupted, positioning information may no longer be accurate. Press

CLEAR

the

key to clear the error message. All display measurements will be zeroed.

Refer to page 4 for information about position recovery.
Counting errors are indicated by the “Scale miscount” message, telling you in

which axis the miscount occurred. Counting errors result from distorted electrical
signals from an encoder. These signals can be a result of an encoder malfunction,

misalignment, mounting problems, or electrical interference. Press the

CLEAR

key to

clear the error message. The axis display (for both absolute and incremental
measurements) will be zeroed. Follow these steps to determine if your difficulties
are associated with the readout or with the encoder.

• Ensure that the linear encoder connectors are correctly seated.

• Swap linear encoder cables at the readout to see if the problem still appears in

the same display.

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

29

Troubleshooting DRO 200M

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

error. Refer to the Checking the Linear Encoders section of your encoder
reference manual.

Display overflow errors are indicated by dashes in all digits in an axis display.
A numeric overflow occurs when the intended measurement is too large for the
eight-digit display. Clear the error by returning the machine table into an area
where measurements can again be displayed, selecting a lower display resolution,
setting a new preset, or zeroing the display.

This error may also occur when using the automatic compensation routine while
setting the LEC parameter. An error indicates that the calculated compensation
factor was outside the acceptable range of -9999 to +9999, and usually is the
result of incorrectly entering data. Clear the error and return to the beginning of
the linear error compensation routine. Refer to page 20.

Data Logging

The readout collects information about itself while it is being used. This
information is stored in memory for review at a later time.

Press and hold the . key until the software version is displayed. Then press the

SETUP

and MM keys simultaneously. Use the X key to cycle through the following

information.

Power on time—displayed in decimal hours.
Scale travel distance—the travel distance in feet for each axis is scrolled one

after the other.
Last 3 errors—the most recent three errors are remembered and messages for

the errors are scrolled one after the other.

30

ACU-RITE Readout Systems are

JAMESTOWN, NEW YORK 14701

manufactured in the USA

ACU-RITE IS AN

ISO 9001

CERTIFIED

MANUFACTURER

2001-704 EDITION C PRINTED IN USA

ACU-RITE INCORPORATED

ONE PRECISION WAY

MASON INDUSTRIAL PARK