Kaman digiVIT User Manual
Non-contact Displacement Measuring
System User’s Manual
Copyright © 2013 Kaman Precision Products
PART NO: 860525-001 A Division of Kaman Aerospace Corporation
Last Revised: 9/16//2013 217 Smith Street
Middletown, CT 06457
www.kamansensors.com
TABLE OF CONTENTS
PART 1 – INTRODUCTION..........................................................................................................4
PART 2 – CONNECTIONS...........................................................................................................5
PART 3 - FRONT PANEL CONTROLS.......................................................................................6
PART 4 – MENU TREE................................................................................................................7
4.2 mA Out Setup ....................................................................................................................8
4.3 Cal Setup ...........................................................................................................................8
4.4 Linearization Options .........................................................................................................8
4.4.1 2 Pt. Cal ......................................................................................................................8
4.4.2 6 Pt. Poly Cal ..............................................................................................................9
4.4.3 21 Pt. Pcws Cal...........................................................................................................9
4.5 Temperature Compensation ..............................................................................................9
4.6 Display Setup...................................................................................................................10
4.6.1 Display Percent.........................................................................................................10
4.6.2 Display Voltage.........................................................................................................10
4.6.3 Display Current .........................................................................................................10
4.7 Advanced Setup................................................................................................................10
4.7.1 Digital Filter...............................................................................................................10
4.7.2 Sample Rate .............................................................................................................11
4.7.3 Ethernet Setup..........................................................................................................11
4.7.4 Keypad Lockout ........................................................................................................11
4.8 Adjust Output ....................................................................................................................11
4.8.1 Zero Output................................................................................................................11
4.8.2 2 Pt. Adjust................................................................................................................11
4.8.3 Clear Zero.................................................................................................................12
4.8.4 3 Pt. Adjust................................................................................................................12
PART 5 - ETHERNET OUTPUT.................................................................................................13
5.1 Default IP Address & Ports ..............................................................................................13
5.2 UDP Packet .....................................................................................................................13
5.3 Console Software.............................................................................................................14
PART 6 - CALIBRATION EXAMPLES........................................................................................15
6.1 General Information .........................................................................................................15
6.2 Calibration Fixturing.........................................................................................................16
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 2 -
6.3 2-Point Linear Calibration .................................................................................................16
6.4 6-Point Polynomial Calibration..........................................................................................17
6.5 21-Point Piecewise Calibration .........................................................................................18
6.6 2-Point Adjustment............................................................................................................19
6.7 3-Point Adjustment............................................................................................................19
6.8 Temperature Compensation (Electronics and Sensor).....................................................20
PART 7 – OTHER FEATURES...................................................................................................21
7.1 Limits & Relay..................................................................................................................21
7.2 IO bit/AUTOZERO............................................................................................................ 21
APPENDIX A: COMMAND LIST.................................................................................................22
APPENDIX B: digiVIT STANDARD PROBE OPTIONS..............................................................24
APPENDIX C: digiVIT TYPICAL SPECIFICATIONS.................................................................26
APPENDIX D: CALIBRATION EXAMPLES VIA ETHERNET INTERFACE ...............................27
APPENDIX E: DIMENSIONS......................................................................................................31
APPENDIX F: SOFTWARE LICENSE AGREEMENT................................................................32
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 3 -
PART 1 – INTRODUCTION
The Kaman digiVIT is a revolutionary inductive displacement measuring instrument. The
digiVIT simplifies use of a variety of Eddy Current sensors for precision measurements of;
displacement, position, vibration, run-out, etc, in typical and difficult applications. The digiVIT is
user configurable and adjustable.
The digiVIT does not require any special factory setup to work with most inductive sensors. It
incorporates a self tuning mechanism that optimizes set up for a given sensor, cable length,
conductive target material, and range. Using the front panel controls, the digiVIT can easily be
calibrated, temperature compensated, and adjusted for a variety of voltage and current output
options.
Getting Started
1.1 Connect Power
A +24 VDC power supply capable of supplying 0.13A is required to power digiVIT. Connect the
power supply to the digiVIT terminal block pins 1 and 2 (reference Part 2 on connections).
1.2 Connect the Sensor
The sensor is connected to the SMA connector. On application of power, if no sensor is
connected or the digiVIT senses and open connection the message 'No Sensor' will appear on
the display. If, the sensor is defective or its resistance is too low, the message 'Bad Sensor' will
be displayed. If the unit was previously calibrated, the display may indicate a voltage, current
or percentage depending on how the display was configured. If voltage or current was not
selected, the default display is percent of full scale.
1.3 Calibrate the Sensor
If factory calibration has not been performed, the sensor must be calibrated before it will
function properly. Reference PART 6 on calibration examples.
1.4 Connect the Outputs
Connect either the analog voltage output, current output, or use the Ethernet port over a UDP
interface. For the analog voltage and current output, output ranges (i.e. 0-5V, +/-5V, 0-10V, +/10V, 0-20mA, or 4-20mA) can be selected using the front panel menu.
For fixturing of sensors and other application considerations, reference Kaman’s Inductive
Technology Handbook. A copy can be downloaded free of charge from Kaman’s website:
www.kamansensors.com
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
.
- 4 -
PART 2 – CONNECTIONS
The digiVIT I/O connections are all through a 10 pin removable terminal block. The DigiVIT
sensor is connected through an SMA coaxial connector on the opposite side of the enclosure.
An RJ45 Ethernet connection is provided for UDP/IP communication.
Pin Name Function
1 +24V
2 Gnd Ground
3 Vout Voltage Output (0-5, +/-5, 0-10, +/-10)
4 Gnd Ground
5 Iout Curent Loop Output (0-20mA, 4-20mA)
6 Gnd Ground
7 NC No Connection
8 IO IO Bit for special functions -- standard setup for Autozero when grounded.
9 Relay Solid State Relay Connection
10 Relay Solid State Relay Connection
+24V Input @ 0.13A
(must accommodate power-on surge current up to 300mA)
Table 1 Terminal Block Pin-Out
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 5 -
PART 3 - FRONT PANEL CONTROLS
The digiVIT can easily be set up using the front panel controls.
1. Sensor connection (SMA)
2. Digital display
3. Scroll up pushbutton
4. Scroll down pushbutton
5. Escape pushbutton
6. Enter pushbutton
7. Ethernet connection (RJ45)
1
2
3
4
5
6
8. I/O screw terminals
7
8
Figure 1 Front Panel Controls
Note: Press the Escape pushbutton (#5 in the figure above) momentarily to return to the
previous menu tree branch. Press and hold the Escape pushbutton to return to the normal run
mode.
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 6 -
PART 4 – MENU TREE
The menu tree for digiVIT, accessed by pushing either the Scroll Up or Scroll Down pushbuttons
on the front panel, is shown below. The Scroll Up and Scroll Down pushbuttons will cycle
through the options in a particular branch. To access a submenu simply scroll up or down in the
main menu until the desired submenu is displayed, then push the Enter pushbutton. To leave a
submenu, momentarily push the Escape pushbutton. To return to the normal run mode,
depress and hold the Escape pushbutton.
Volt Out
Setup
mA Out
Setup
Cal
Setup
Display
Setup
Advanced
Setup
Adjust
Output
Return to
Run
Zero
Output
2 PT
Adjust
Clear
Zero
3 PT
Adjust
Digital
Filter
Sample
Rate
Ethernet
Setup
Keypad
Lockout
Relay
Limits
Relay
Polarity
Relay Hi
Limit
Relay Lo
Limit
Relay
Hysteresis
IP
Address
UDP Port
Writer
UDP Port
Reader
Mac
Address
5000
SPS
10000
SPS
Display
Percent
Display
Voltage
Display
Current
Linearize
Output
Temp Cmp
Sensor
Temp Cmp
Electronics
2 PT
Lin Cal
6 PT
Poly Cal
21 PT
Pcws Cal
4-20mA
Current
0-20mA
Current
0-10V
Output
+/-10V
Output
0-5V
Output
+/-5V
Output
Figure 2 Menu Tree
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 7 -
4.1 Volt Out Setup
This option allows selection of the voltage output range from the system.
The actual voltage will go 1% above or below the voltage output range selected if the sensor is
above or below the calibrated range.
4.2 mA Out Setup
This option allows selection of the current output range from the system.
The actual current will go 5% above or below the current output range selected if the sensor is
above or below the calibrated range. In the case of 0-20mA output, it will not go below zero.
4.3 Cal Setup
This selection allows linearization calibration and temperature compensation. With the
exception of the 2 Pt. or 3 Pt. Adjust (reference 4.8) all other calibration methods will zero out
the temperature compensation coefficients and any offset.
4.4 Linearization Options
3 options are available for linearization calibration, 2 point, 6 point and 21 point.
Note: Performing a linearization calibration after a temperature compensation calibration will
void the temperature compensation calibration. All linearization calibrations begin by locating
the sensor at the maximum distance it will be from the target during operation. This is typically
the sum of the offset distance and full scale range.
4.4.1 2 Pt. Cal
The 2 point calibration is useful if either linearity of the output is not a concern or if the sensor is
operated over a very short range. Ranges less than 10% of the standard range (a standard
range is normally 33% of the sensor diameter) typically will result in good linearity. For ranges
below 5% of the standard range; this is the recommended method.
To perform a 2 Pt calibration, the sensor needs to be position at MAX distance from the sensor
face (i.e. full scale) so that it can optimize for a given sensor. After that, the sensor needs to be
positioned at only the offset (MIN) and full range (MAX) positions.
Note: Any previous temperature compensation calibration will be voided when a 2 Pt. calibration
is performed.
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 8 -
4.4.2 6 Pt. Poly Cal
The 6 point polynomial cal fits a 5th order polynomial through the data points to linearize the
sensor output. In most cases this method works very well though there can be exceptions.
The sensor needs to be position at MAX distance from the sensor face (i.e. full scale) so that it
can optimize for a given sensor. After that the sensor needs to be position at offset (MIN) and
then at 20%, 40%, 60%, 80%, and 100% of the range to complete the calibration.
Note: Any previous temperature compensation calibration will be voided when a 6 Pt. calibration
is performed.
4.4.3 21 Pt. Pcws Cal
This calibration will result in the best performance. It is a 21 point piecewise linearization
method. This option works best if the curve is too oddly shaped for a polynomial to fit well.
The sensor needs to be positioned at the MAX distance from the sensor face (i.e. full scale) so
that it can optimize for a given sensor. After that, it needs to be positioned in 5% of the range
increments from 0-100%.
Note: Any previous temperature compensation calibration will be voided when a 21 Pt.
calibration is performed.
4.5 Temperature Compensation
The digiVIT optimizes the sensor for temperature stability and linearity using proprietary
algorithms. However, even with this optimization, some residual error exists due to
temperature. Temperature stability can generally be improved by a factor of 5-10 using
additional steps to temperature compensate the unit. To perform temperature compensation,
data from 2 different displacements with 2 different temperatures must be acquired by the unit.
The actual displacement does not matter, but the recommended displacements are
aproximately10% and 90% of the calibrated range. If the best temperature coefficient is desired
at a particular displacement, that displacement should be chosen as one of the displacements
used. The temperature compensation algorithm will have the smallest temperature error at that
displacement 1 and 2 when the calibration is completed. The 4 required points are:
D1T1 (Displacement 1, Temperature 1)
D1T2 (Displacement 1, Temperature 2)
D2T1 (Displacement 2, Temperature 1)
D2T2 (Displacement 2, Temperature 2)
The temperature compensation calibration menu controls the order of the 4 points.
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 9 -
When temperature compensation is selected, the display shows a temperature relative to when
the calibration process started. It is displayed in degrees Celsius, but is not particularly
accurate in terms of absolute temperature.
The first step is to go to D1T1, it does not matter if it is at the 10% or 90% point (or any point)
and it does not matter what order you take the two temperature points in (rising or falling
temperature). At this displacement, change the temperature of the sensor noting the output on
the display. It is best to avoid transients so by heating (or cooling) the sensor it is best to wait
until any transients have passed to take the data point. The unit does not care what the actual
temperatures used for the calibration are and they do not have to be the same for both
displacements. One method is to heat the sensor up some number of degrees, take one data
point after any transients have passed, and take the second data point after it has cooled down
some. After the two temperature points have been collected at displacement 1, then position
the sensor at displacement 2 and take two temperature points again.
If changing the temperature resulted in slight offset and gain errors due to actual position
changes, a 2 or 3 point adjustment calibration can be performed (see section 4.8.2 or 4.8.4).
Temperature coefficients are not affected by a 2 point or 3 point adjustment calibration.
4.6 Display Setup
The display has several different output options:
4.6.1 Display Percent
Displays the percentage of the calibrated range where the sensor is positioned. Over and under
range will show greater than 100% and less than 0% but the voltage outputs will be constrained
to -1% to +101%. Current outputs are constrained to -5% to +105% (but will not go below
0mA).
4.6.2 Display Voltage
Displays the selected voltage output.
4.6.3 Display Current
Displays the selected current output.
4.7 Advanced Setup
4.7.1 Digital Filter
The display is always filtered but the analog outputs (voltage and current) are not. Resolution of
these outputs can be increased using a digital filter. The time constant options (tau) will vary
www.kamansensors.com PART NO: 860525-001
Last Revised 9/16/2013
- 10 -
Loading...