KVH® DSP-1760 Multi-axis Gyroscope
Technical Manual

DSP-1760

DSP-1760 Technical Manual

DSP-1760 Technical Manual
The KVH Industries’ DSP-1760 Multi-axis Gyroscope is an ultra-compact, extremely precise, guidance and stabilization system using KVH's advanced proprietary fiber optic gyros. The small, lightweight, low power, and rugged DSP-1760 offers accurate performance in extreme environments, and includes environmental and electromagnetic protection. Its flexible digital data and power interface is designed for ease of integration in new applications and upgrades to existing systems.

Micro-D Connector

Circular Connector

Please direct questions, comments, or suggestions to:
KVH Industries, Inc. 50 Enterprise Center Middletown, RI 02842 USA Tel: +1 401 847-3327 Fax: +1 401 849-0045 E-mail: fogsupport@kvh.com Internet: www.kvh.com
If you have any comments regarding this manual, please e-mail them to manuals@kvh.com. Your input is greatly appreciated!
KVH Part # 54-0924 Rev. A © 2013, KVH Industries, Inc., All rights reserved.
Protected by U.S. and foreign patents

DSP-1760 Technical Manual Table of Contents
Table of Contents
Product Variants ................................................................................1 Product Specifications.......................................................................2 Storage and Handling ........................................................................8 Maintenance ......................................................................................8 Output Orientation .............................................................................8 Interface Connector ...........................................................................9 Interface Cable ................................................................................11 Data Communications Equipment ...................................................11 Wiring the Gyro ................................................................................12 Digital Data Output ..........................................................................14
Message Structure ....................................................................15 User-Configurable Parameters..................................................17 Resetting Parameters to Factory Defaults.................................18 User Commands ..............................................................................19 Time of Validity (TOV) Output ...........................................................20 Master Sync (External Clock)...........................................................21 Hardware Restart ............................................................................22 Mounting the Gyro ...........................................................................23 Troubleshooting ............................................................................... 24 Built-In Test (BIT).......................................................................25 Technical Support............................................................................27 Appendix A: Patent Protection .........................................................29
i

DSP-1760 Technical Manual Product Variants

Product Variants
This manual supports the following six DSP-1760 variants (two interface connector options, each with the option of one, two, or three axes of fiber optic gyros).

Part Number
01-0352-01 01-0352-02 01-0352-03 01-0354-01 01-0354-02 01-0354-03

Number of Gyros
1 2 3 1 2 3

Connector Type
Micro-D Micro-D Micro-D Circular Circular Circular

Axes with Configurable Output (see pg. 8)
Z
X and Z
X, Y, and Z
Z
X and Z
X, Y, and Z

Information provided in this manual is common to all variants unless otherwise noted. Technical and performance specifications, interface data, mounting guidelines, and a brief troubleshooting guide are included.

1

DSP-1760 Technical Manual Product Specifications

Product Specifications
Product specifications are provided in Figure 1.

NOTE: Performance specifications are based on a 1000 Hz data rate and 921.6 kbaud baud rate.

Figure 1: DSP-1760 Specifications Attribute Performance - Gyros Input Rate Bias Stability (constant temp.)
Bias Offset (room temp.) Bias Temperature Sensitivity Scale Factor Non-Linearity Scale Factor Temperature Sensitivity Angle Random Walk (ARW) (room temp.) Input Axis Misalignment

Value
±490°/s max. ≤0.05°/hr-1 typical, 0.10°/hr-1 max. ±2°/hr ≤1°/hr-1(1°C/minute ramp) ≤50 ppm-1 (full rate) ≤200 ppm-1
≤0.012°/hr ≤0.7°/hr/Hz

1 Axis (Z) ±8.0 mrad (Z-X) ±8.0 mrad (Z-Y) —

2 Axis (X-Z) ±0.4 mrad (Z-X) ±8.0 mrad (Z-Y) ±8.0 mrad (X-Y)

3 Axis (X-Y-Z) ±0.4 mrad (Z-X) ±0.4 mrad (Z-Y) ±0.4 mrad (X-Y)

Bandwidth (-3 dB)

≥440 Hz

Environment

Temperature (operating)

-40°F to +167°F (-40°C to +75°C)

Temperature (storage)

-58°F to +185°F (-50°C to +85°C)

Vibration (operating)

8 g rms (20-2000 Hz, random)

Vibration (non-operating)

12 g rms (20-2000 Hz, random)

Shock (operating)

25 g (11 ms, sawtooth)

Shock (non-operating)

40 g (11 ms, sawtooth)

2

DSP-1760 Technical Manual Product Specifications

Attribute

Value

Digital Data Output

Format

RS422

Data Rate

1 to 1000 Hz, user-selectable

Baud Rate

9.6 to 921.6 kbaud, user-selectable

Turn-On Time (room temp.)

≤1.25 s (valid data)

Full Performance Time (room temp.) ≤60 s

Power Supply

Input Voltage

9-36 VDC

Input Power

1 Axis: 3 W typical, 6 W max. 2 Axis: 4 W typical, 7 W max. 3 Axis: 5 W typical, 8 W max.

Package

Weight (nominal)

1 Axis: 1.10 lbs (0.50 kg) 2 Axis: 1.20 lbs (0.54 kg) 3 Axis: 1.32 lbs (0.60 kg)

Dimensions (nominal)

Ø3.5" x 2.9" h (88.9 mm x 73.7 mm) Also see Figures 2 & 3 that follow

IMPORTANT!
The DSP-1760 is a precision instrument. Handle the unit with care and avoid exposing it to severe mechanical shock.

3

DSP-1760 Technical Manual Product Specifications

General dimensions are provided below.

NOTE: All dimensions are shown in inches [millimeters] format.

Figure 2: General Dimensions (Micro-D Connector)

Top View

CL

CL 3.79 [96.4]
CL

Side View

CL

1.06 [26.9]
CL
0.14 [3.6]
2.90 [73.7]

CL Ø3.50 [88.9]
4

Figure 3: General Dimensions (Circular Connector)

Top View

CL

DSP-1760 Technical Manual Product Specifications

CL 3.79 [96.4]
CL

Side View

CL

1.15 [29.2]
CL
0.48 [12.1]
2.90 [73.7]

CL Ø3.50 [88.9]
5

DSP-1760 Technical Manual Product Specifications
Center of Gravity locations for each variant are provided below. NOTE: All dimensions are shown in inches [millimeters] format.
Figure 4: Center of Gravity (Micro-D Connector) Top View
CL
1 Axis: 1.12 [28.4] 2 Axis: 1.06 [26.9] 3 Axis: 1.00 [25.4]

Side View

Center of Gravity
CL
CL 1 Axis: 0.05 [1.3] 2 Axis: 0.00 [0.0] 3 Axis: 0.05 [1.3]

CL Center of Gravity

1 Axis: 1.37 [34.8] 2 Axis: 1.32 [33.5] 3 Axis: 1.29 [32.8]

6

Figure 5: Center of Gravity (Circular Connector)

Top View

CL

DSP-1760 Technical Manual Product Specifications
1 Axis: 1.21 [30.7] 2 Axis: 1.15 [29.2] 3 Axis: 1.09 [27.7]

Side View

Center of Gravity
CL
CL 1 Axis: 0.05 [1.3] 2 Axis: 0.00 [0.0] 3 Axis: 0.05 [1.3]

Center of Gravity

CL

1 Axis: 1.37 [34.8] 2 Axis: 1.32 [33.5] 3 Axis: 1.29 [32.8]
7

DSP-1760 Technical Manual Storage and Handling

Storage and Handling
The DSP-1760 may be stored in a location with an environmental temperature between -58°F to +185°F (-50°C to +85°C). Ideally, the unit should be stored at a room temperature of approximately 70°F (21°C).
The DSP-1760 is a sensitive measuring device. Take normal safety precautions when handling to ensure the integrity of the device. During unpacking and installation, proper ESD handling procedures should be enforced.

Maintenance
The DSP-1760 is supplied as a sealed unit; there are no field maintainable components. Opening the enclosure will void the warranty and may violate the contract under which the unit was supplied.

Output Orientation

The DSP-1760 senses rotation on up to three configurable axes. The measurement axes are shown in Figure 6. You may configure a rotation matrix to set the output axes relative to the physical orientation of these measurement axes, allowing the gyro to measure motion in arbitrarily orthogonal axes (see “User-Configurable Parameters” on page 17). These settings are saved and reapplied on restart. You may revert to the factory default settings at any time (see “Resetting Parameters to Factory Defaults” on page 18).

Figure 6: Gyro Measurement Axes Orientation (shown with Micro-D Connector)

Top View
CL

Side View
+Z

+X

CL

+Y

CL

8

DSP-1760 Technical Manual Interface Connector

Interface Connector
The DSP-1760 is equipped with one of the following male connector types:

• 15-pin Micro-D interface connector: Meets MIL-DTL-83513
• 13-pin circular interface connector: Comparable to MIL-DTL-D38999

Figure 7 shows the location for either type connector. Figure 8 describes the function of each pin for the Micro-D connector, and Figure 9 describes the function of each pin for the circular connector.

Figure 7: Interface Connector Location

Interface Connectors Pin 1

15-Pin Micro-D Pin 1
or

13-Pin Circular

9

DSP-1760 Technical Manual Interface Connector

Figure 8: Micro-D Interface Connector Pins

Pin Type

Description

1

RS422-TX (+) Gyro RS422 Transmit High

2

RS422-TX (–) Gyro RS422 Transmit Low

3

RS422-RX (–) Gyro RS422 Receive Low

4

RS422-RX (+) Gyro RS422 Receive High

5-8 –

Reserved – Do Not Connect

9

Power (–)

Power Return

10 Power (+)

9-36 VDC Power Input

11 MSync

Master Sync Input (External Clock) (Optional)

12 TOV-Out

Time of Validity Signal (Optional)

13 Config-RST-In Gyro Configuration Reset (Software)

14 EXT-RST

Gyro Reset (Power)

15 Signal-GND

Common Ground

Figure 9: Circular Interface Connector Pins

Pin Type

Description

1

RS422-RX (–) Gyro RS422 Receive Low

2

RS422-TX (+) Gyro RS422 Transmit High

3

Power (–)

Power Return

4

Power (+)

9-36 VDC Power Input

5

TOV-Out

Time of Validity Signal (Optional)

6

Signal-GND

Common Ground

7

–

Reserved – Do Not Connect

8

RS422-RX (+) Gyro RS422 Receive High

9

RS422-TX (–) Gyro RS422 Transmit Low

10 MSync

Master Sync Input (External Clock) (Optional)

11 Config-RST-In Gyro Configuration Reset (Software)

12 EXT-RST

Gyro Reset (Power)

13 –

Reserved – Do Not Connect

10

DSP-1760 Technical Manual Interface Cable
Interface Cable
The power and data interface cable must be fitted with one of the following: • If equipped with the 15-pin Micro-D interface connector:
A 15-socket (female) Micro-D connector per MIL-DTL-83513 with a Flourosilicone interfacial seal is required to comply with the environmental testing performed at KVH. You can purchase a 24" (60 cm) shielded interface cable with this connector from KVH (KVH part no. 32-1173-02). • If equipped with the 13-pin circular interface connector: A Cleeve Technologies FAE-1B-01-007-26MT8-13SA 13-socket (female), or a Glenair® Series Mighty Mouse 801-007-26MT8-13SA 13-socket (female) circular connector with a shielded cable harness is required to comply with the environmental testing performed at KVH. You can purchase a 24" (60 cm) shielded interface cable with this connector from KVH (KVH part no. 32-1173-01). If your application requires a serial cable or interface adapter (such as an RS422-USB serial adapter), make sure it is compatible with the gyro and supports speeds of at least 921.6 kbaud. Also be sure to use shielded cables to prevent signal loss and noise interference.
Data Communications Equipment
A computer or other data communications device is necessary to communicate with the gyro. This equipment's serial port communications must match the gyro’s serial port settings for proper operation. When connected to the gyro, you can enter commands directly from the terminal or through a terminal emulation application, such as Windows® HyperTerminal. NOTE: The DSP-1760 outputs binary data which may be interpreted as control codes. To ensure reliable communications, select an appropriate terminal emulator or proper emulation options.
11

DSP-1760 Technical Manual Wiring the Gyro

Wiring the Gyro

Use Figure 10 or Figure 11 as a guide to connect the gyro to your application.

Figure 10: Wiring Diagram (15-pin Micro-D Connector)

Pin

1

RS422-TX (+)

2

RS422-TX (–)

3

RS422-RX (–)

4

RS422-RX (+)

5

6 Do Not Connect
7
8

DC Supply

Customer Interface (RS422)

9

Power (–)

Power Return

10

Power (+)

9-36 VDC

11

MSync

12

TOV-Out

13

Config-RST-In

14

EXT-RST

Customer Interface
(see page 20 for TOV details;
see page 21 for MSync details)

15

Signal-GND

Case (Shield)

Chassis Ground

NOTE: Pins 11 through 14 are referenced to signal ground on pin 15 (not the power ground on pin 9). Signal ground and power ground are tied together internally at the gyro.

12

DSP-1760 Technical Manual Wiring the Gyro

Figure 11: Wiring Diagram (13-pin Circular Connector)

Pin

1

RS422-RX (–)

2

RS422-TX (+)

3

Power (–)

DC Supply Power Return

4

Power (+)

9-36 VDC

5

TOV-Out

Customer Interface
(see page 20 for details)

6

Signal-GND

7

Do Not Connect

8

RS422-RX (+)

9

RS422-TX (–)

10

MSync

Customer Interface

11

Config-RST-In

(see page 21 for

MSync details)

12

EXT-RST

13

Do Not Connect

Case (Shield)

Chassis Ground

Customer Interface (RS422)

NOTE: Pins 5 and 10 through 12 are referenced to signal ground on pin 6 (not the power ground on pin 3). Signal ground and power ground are tied together internally at the gyro.

13

DSP-1760 Technical Manual Digital Data Output

Digital Data Output

The gyro provides a digital interface with the following characteristics:

Figure 12: Interface Characteristics

Parameter

Value

Type

RS422

Baud Rate (kbaud) Selectable: 9.6, 19.2, 38.4, 57.6, 115.2, 460.8, 576.0, 921.6 (default)

Parity

None

Start Bits

1 (space, binary 0)

Data Bits

8 (1 message byte, starting with LSB)

Stop Bits

1 (mark, binary 1)

Flow Control

None

An idle line is always marking (in a binary 1 state). Thirty-six (36) characters in sequence constitute a basic message.
NOTE: The gyro’s RS422 RX signals are internally terminated to 100

14

DSP-1760 Technical Manual Digital Data Output

Message Structure
The output message contains 36 bytes. The most significant byte is sent first; and the most significant bit of each byte is sent first. Figure 13 and Figure 14 define the format of the message.

Figure 13: Message Format

Function

Total # Bytes

Header

4

Message data

28

CRC (Cyclic

4

Redundancy Check)

Description
Always 0xFE81FF55; this value will never occur anywhere else
See Figure 14
See Figure 16 on page 16

Figure 14: Message Data

Datum

Byte Number(s)

Data Type*

Selectable Units/ Range/Format

Notes

X rotational data**

0,1,2,3

SPFP

Radians or degrees; Rate of rotation or delta angle

Byte 0 is output first

Y rotational data**

4,5,6,7

SPFP

Radians or degrees; Rate of rotation or delta angle

Byte 4 is output first

Z rotational data 8,9,10,11

SPFP

Radians or degrees; Rate of rotation or delta angle

Byte 8 is output first

Reserved

12,13,14,15 N/A

N/A

Reserved

16,17,18,19 N/A

N/A

Reserved

20,21,22,23 N/A

N/A

Status

24

DISC 1 = valid data

See Figure 15 on

0 = invalid data

page 16

Sequence

25

Number

UINT8 0-127

Increments for each message and resets to 0 after 127

Temperature

26,27

INT16

°C or °F, selectable

Rounded to the nearest whole degree

* SPFP = Single Precision Floating Point (IEEE-754); DISC = Discrete Data; UINT8 = Unsigned 8-bit integer; INT16 = Signed 16-bit integer.

** Ignore this field if the associated gyro is not installed.

15

DSP-1760 Technical Manual Digital Data Output

Figure 15: Status Byte Format Function Gyro X status* Gyro Y status* Gyro Z status Reserved Reserved Reserved Reserved Reserved

Bit # 0 1 2 3 4 5 6 7

Notes LSB Always 0
Always 0

NOTE: In addition to this general status information, an extended built-in test (BIT) may be initiated at any time by entering the “?bit” command. (Extended BIT data is also output whenever the gyro is first powered on.) The extended BIT provides six bytes of diagnostic data. For details, refer to the DSP-1760 Electrical Signaling ICD (KVH part no. 56-0288).

* If not included, a value of 0 (zero) is reported.

Figure 16: CRC Format

Parameter Value

Width

32

Poly

0x04C11DB7

Reflect In

False

XOR In

0xFFFFFFFF

Reflect Out False

XOR Out

0

16

DSP-1760 Technical Manual Digital Data Output

User-Configurable Parameters
The DSP-1760 offers several configurable parameters (see Figure 17).

Figure 17: User-Configurable Parameters

Parameter

Command Options

Baud Rate (kbaud)

=baud

• 9.6 • 19.2 • 38.4 • 57.6

• 115.2 • 460.8 • 576.0 • 921.6

Data Rate (Hz) =dr

•1 •5 • 10 • 25 • 50

• 100 • 250 • 500 • 750 • 1000

Temperature Units

=tempunits

• °C • °F

Angular Units

=rotunits

• Radians • Degrees

Rotational Data =rotfmt

• Delta Angle (radians or degrees)
• Rate of Rotation (radians or degrees/second)

Output Filter

=filten

• Enabled • Disabled

=filttype,g

• Chebyshev • Butterworth • Uniform Averager • Custom

=fc,g

Gyro filter coefficients (custom filter)

Default 921.6 kbaud
1000 Hz
°C Radians Delta Angle
Enabled Chebyshev
Chebyshev filter

17

DSP-1760 Technical Manual Digital Data Output

Parameter
X, Y, Z Axis Definitions

Command =axes

Output

=msync

Synchronization

Options
Floating point values defining a 3x3 rotation matrix (sets the output axes relative to the physical orientation of the measurement axes - see page 8)
• Gyro (internal clock)
• External

Default 1 0 0 0 1 0 0 0 1
Gyro

For complete details on modifying settings, refer to the DSP-1760 Electrical Signaling ICD (KVH part no. 56-0288). Settings are saved and reapplied on restart. You may revert to the factory default settings at any time (see “Resetting Parameters to Factory Defaults”).
NOTE: Changing parameters from their default values may impact performance.
With the exception of baud rate, you can query the current value of any parameter by entering the corresponding “?” command. For example, to view the current data rate, you would enter the “?dr” command.
To enter any configuration command, the gyro must first be set to Configuration mode. In Configuration mode, the gyro stops sending data and listens for user commands (a terminal prompt indicates the gyro is ready to accept commands). To put the gyro in Configuration mode, enter the “=config,1” command. When you are done configuring the unit, enter the “=config,0” command to exit Configuration mode and return to the Normal mode of operation.

Resetting Parameters to Factory Defaults
There are two options for resetting all of the user-configurable parameters to their factory default values.
Option 1: Enter the “=rstcfg” command in Configuration mode.
Option 2: Apply +3.3V to gyro Configuration Reset (Config-RST-In) on pin 13 of the Micro-D interface connector, or pin 11 of the circular interface connector. During startup, the gyro monitors this pin and will reset the user-configurable parameters if it detects +3.3V. The pin is ignored during normal operation. The pin may be left disconnected until you need to perform a reset.
18

DSP-1760 Technical Manual User Commands

User Commands
In addition to the configuration commands described in “UserConfigurable Parameters” on page 17, the following commands are also available to the user. For complete details on using these commands, refer to the DSP-1760 Electrical Signaling ICD (KVH part no. 56-0288).

Figure 18: User Commands

Command Description

?bit

Initiates an extended built-in test in Normal mode

=config

Puts the unit into or out of Configuration mode

?config

Reports whether or not the gyro is currently running in Configuration mode

=echo (or ?echo)

Reports how many times the echo command has been called; useful for verifying communications to the unit

=help (or ?help)

Displays a list of available commands

?is

Reports the serial number of the system

=restart

Restarts the gyro

=rstcfg

Resets all user-configurable parameters to their factory default values

?temp

Reports the internal temperature of the gyro; detected by the controller board

=testfilt (or ?testfilt)

Tests the configured output filter response to a unit impulse

?volt

Reports all available voltages on the controller board

?ws

Reports the axis quantity and software versions of gyro

components

All commands must be entered while the gyro is in Configuration mode except “?bit” (entered in Normal mode) and “=config” (entered in Configuration or Normal mode).

19

DSP-1760 Technical Manual Time of Validity (TOV) Output

Time of Validity (TOV) Output
The DSP-1760 provides an optional Time of Validity output (TOVOut) on pin 12 of the Micro-D interface connector, or pin 5 of the circular interface connector, to indicate the precise timing of the gyro’s measurement data.
Figure 19: TOV Output Timing Relative to Serial Port Activity
T1 3.3 VDC TOV Output
T2
T4
T3
Serial Port Active

Figure 20: TOV Timing Parameters

Parameter Description

T1

TOV active

T2

TOV period

T3

Duration of serial

port output

T4

Time between rising

edge of TOV-Out

and start of data

transmission

Value
10% of the TOV period (at default data rate of 1000 Hz, T2 = 1 ms and T1 = 100 s)
Determined by the output data rate (at default data rate of 1000 Hz, T2 = 1 ms)
Depends on baud rate; equal to the number of characters output (36) multiplied by the number of bits per character (10) divided by the baud rate (at default baud rate of 921.6 kbaud,
T3 = 390.6 µs)
<500 s

20

DSP-1760 Technical Manual Master Sync (External Clock)

Master Sync (External Clock)
The DSP-1760 can accept an optional user-supplied master sync signal on pin 11 of the Micro-D connector, or pin 10 of the circular connector. The gyro’s output will be triggered on the rising edge of this master sync signal. The signal’s amplitude must be +3.3V and the driver must be capable of sourcing at least 10 mA.
Figure 21: Master Sync
T1
3.3 VDC MSync
T2
T3

Figure 22: MSync Timing Parameters

Parameter Description

T1

MSync high

T2

MSync low

T3

Period between rising edges

Value 30 s 100 s 1-2000 ms

To synchronize the gyro’s output with an external signal on pin 11 (Micro-D connector) or pin 10 (circular connector), enter the “=msync,ext” command in Configuration mode. Upon initiating the “=msync,ext” command, the gyro automatically clears any userselected output filter and switches to the Uniform Averager setting. This allows you to use the MSync signal as an asynchronous request for data, rather than an external clock. However, you may override this behavior by choosing any output filter using the appropriate Output Filter commands provided in Figure 17 on page 17. Be sure to enter the Output Filter commands AFTER you have entered the “=msync,ext” command.
NOTE: Consecutive rising edges of the MSync signal must be between 1-2000 ms apart. Pulsing MSync faster than 1 ms may result in inaccurate or corrupt data output. If the gyro does not detect a rising edge within 2000 ms, it will output data upon reaching 2000 ms.

21

DSP-1760 Technical Manual Hardware Restart
Hardware Restart
Pin 14 (EXT-RST) of the Micro-D interface connector, or pin 12 of the circular interface connector, can be used to reboot the gyro. The gyro monitors this pin at all times and will reboot if it detects +3.3V. The pin may be left disconnected until you need to restart the gyro.
22

DSP-1760 Technical Manual Mounting the Gyro

Mounting the Gyro

The DSP-1760 is easily mounted to a structure using the four 0.173" (4.39 mm) mounting holes on the base of the enclosure (see Figure 23). An alignment hole 0.198" (5.03 mm) and an alignment slot 0.218" x 0.198" (5.54 mm x 5.03 mm) are provided at the middle edge of the enclosure for alignment purposes. They are designed for 0.1970"-0.1973" (5.004-5.012 mm) dowel pins with 0.1" (2.5 mm) protrusion.

NOTE: To ensure precise alignment, rotate the gyro clockwise before tightening the mounting screws.

The gyro base material is aluminum with a clear chromate finish per MIL-DTL-5541, class 3. To ensure optimal heat transfer (conductive cooling) and electrical grounding through the chassis, mount the gyro base to a clean, flat, unpainted metal surface.
Also be sure to orient the gyro with the desired measurement axes. As an alternative, you may configure a rotation matrix to set the output axes relative to the physical orientation of the measurement axes (see “User-Configurable Parameters” on page 17).

NOTE: All dimensions are shown in inches [millimeters] format.

Figure 23: Mounting Holes (Bottom View)

Bottom View

Mounting Hole 4x Ø0.173 [4.39]

2.432 [61.77]

2.432 [61.77]

0.218 [5.54]

CL

0.1980 ±0.0005 [5.029 ±0.013]
0.110 [ 2.8]
Alignment Slot

Alignment Hole Ø0.1980 ±0.0005 [Ø5.029 ±0.013]
0.110 [ 2.8]
CL
0.04 [1.02]

2.750 [69.85]

23

DSP-1760 Technical Manual Troubleshooting

Troubleshooting
This chapter explains how to diagnose basic problems.
IMPORTANT!
The DSP-1760 is supplied as a sealed unit. Breaking the QA seals voids the warranty and may violate the contract under which the unit was supplied. The warranty does not apply if the unit has been damaged by misuse or as the result of service or modification other than by KVH Industries.

Figure 24: Basic Troubleshooting

Problem

Solution

The unit does not power up.

Check the input power supply. 12 VDC (nominal) is recommended for stable performance. The supply should also draw between 3-8 W over the entire operating temperature range. If the power supply is OK, check the power cable and wiring.

The unit does not communicate.

Check the interface cable and make sure your equipment’s serial port settings match the gyro’s settings (see Figure 12 on page 14).

Incoherent data is streaming.

Ensure the baud rate of your interface port is set to one of the valid configurable baud rates (see Figure 12 on page 14 for details). Also make sure your parsing algorithm is correct.

The unit is not sending data at the set data rate.

Ensure the set baud rate is fast enough to support the chosen data rate (see Figure 25 on page 25). Verify with an oscilloscope.

24

DSP-1760 Technical Manual Troubleshooting

Figure 25: Recommended Baud Rate/Data Rate Limits

Baud Rate (kbaud) Maximum Data Rate (Hz)

9.6

10

19.2

25

38.4

50

57.6

100

115.2

100

460.8

500

576.0

750

921.6

1000

Built-In Test (BIT)
The gyro’s built-in test (BIT) monitors system performance and status to ensure it is operating within its specifications. BIT test results are output in three ways:
• Continuous BIT – The Continuous BIT is output as part of the gyro’s output message during operation (see “Continuous BIT Status Information” on page 26).
• Startup Extended BIT – When the gyro is powered on, it outputs the extended BIT status message (see “Extended BIT Status Information” on page 26).
• User-requested Extended BIT – When you enter the “?bit” command in Normal mode, the gyro outputs the extended BIT status message (see “Extended BIT Status Information” on page 26).

25

DSP-1760 Technical Manual Troubleshooting

Continuous BIT Status Information
As indicated in Figure 14 on page 15, byte 24 of the gyro’s output message (excluding the message header) reports the general status of the gyros. Converted to hexadecimal, a status byte of “01” for the 1 axis version, “02” for the 2 axis version, and “03” for the 3 axis version indicates normal status.

Figure 26: Status Byte Format

Datum

Bit #

Notes

Gyro X

0 (LSB) 1 = Valid data, 0 = Invalid data*

Gyro Y

1

1 = Valid data, 0 = Invalid data*

Gyro Z

2

1 = Valid data, 0 = Invalid data

Reserved

3

Always 0

Reserved

4

Reserved

5

Reserved

6

Constant Zero

7

Always 0

* Unpopulated gyros have a status of zero.

Extended BIT Status Information
When the gyro is first powered on, and upon user request, the gyro outputs an extended BIT message consisting of six bytes of detailed status information for diagnostics. Converted to hexadecimal, the following message indicates normal status: “FE 81 00 AA 7F 7F 7F 7F 7F 7F 23”.

Figure 27: Extended BIT Message Format

Function

Total # Bytes

Header

4

Message data

6

Checksum

1

Description
Always 0xFE8100AA
Refer to the DSP-1760 Electrical Signaling ICD (KVH part no. 56-0288) for details
Calculated by accumulating the sum of each byte of data, modulo 256

26

DSP-1760 Technical Manual Technical Support
Technical Support
For technical support, please e-mail your question or a description of your problem to fogsupport@kvh.com.
27

DSP-1760 Technical Manual Appendix A: Patent Protection

Appendix A: Patent Protection
One or more of the following U.S. and international patents* protect the technology in KVH fiber optic gyros:

KVH Patent Numbers

DE 69722994

US 6,041,149

DE 69734809.1

US 6,134,356

EP 60130780 T2 US 6,351,310 B1

EP 1,314,002

US 6,370,289 B1

FR 0802397

US 6,429,939

GB 0802397

US 6,466,596

US 5,126,666

US 6,542,651

US 5,340,371

US 6,563,589

US 5,444,534

US 6,718,097

US 5,481,358

US 6,763,153

US 5,552,887

US 6,836,334

US 5,739,944

US 7,120,323

US 5,768,462

*Additional patents pending

29

KVH Industries Limited Warranty DSP-1760
LIMITED WARRANTY ON HARDWARE KVH Industries, Inc. warrants the KVH Fiber Optic Gyro purchased against defects in materials and workmanship for a period of ONE (1) year from the date of original retail purchase by the original purchaser. If you discover a defect, KVH will, at its option, repair, replace or refund the purchase price of the product at no charge to you, provided you return it during the warranty period, transportation charges prepaid, to the factory direct. Please attach your name, address, telephone number, a description of the problem and a copy of the bill of sale or sales receipt as proof of date of original retail purchase, to each product returned to warranty service. This Limited Warranty does not apply if the product has been damaged by accident, abuse, misuse, or misapplication or has been modified without the written permission of KVH; if any KVH serial number has been removed or defaced; or if any factory-sealed part of the system has been opened without authorization. THE EXPRESS WARRANTIES SET FORTH ABOVE ARE THE ONLY WARRANTIES GIVEN BY KVH WITH RESPECT TO ANY PRODUCT FURNISHED HEREUNDER; KVH MAKES NO OTHER WARRANTIES, EXPRESS, IMPLIED OR ARISING BY CUSTOM OR TRADE USAGE, AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. SAID EXPRESS WARRANTIES SHALL NOT BE ENLARGED OR OTHERWISE AFFECTED BY TECHNICAL OR OTHER ADVICE OR SERVICE PROVIDED BY KVH IN CONNECTION WITH ANY PRODUCT. KVH’s liability in contract, tort or otherwise arising out of or in connection with any product shall not exceed the price paid for the product. IN NO EVENT SHALL KVH BE LIABLE FOR SPECIAL, PUNITIVE, INCIDENTAL, TORT OR CONSEQUENTIAL DAMAGES OR LOST PROFITS OR GOODWILL (INCLUDING ANY DAMAGES RESULTING FROM LOSS OF USE, DELAY IN DELIVERY OR OTHERWISE) ARISING OUT OF OR IN CONNECTION WITH THE PERFORMANCE OR USE OR POSSESSION OF ANY PRODUCT, OR ANY OTHER OBLIGATIONS RELATING TO THE PRODUCT, EVEN IF KVH HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. If any implied warranty, including implied warranties of merchantability and fitness for a particular purpose, cannot be excluded under applicable law, then such implied warranty shall be limited in duration to ONE (1) YEAR from the date of the original retail purchase of this product by the original purchaser. Some states do not allow the exclusion or limitation of implied warranties or liability for incidental or consequential damages, so the above limitations may not apply to you. This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.

DSP-1760_cover

KVH Industries, Inc. 50 Enterprise Center • Middletown, RI 02842 • U.S.A. Phone: +1 401 847-3327 • Fax: +1 401 849-0045 • E-mail: info@kvh.com • Internet: www.kvh.com
KVH is a registered trademark of KVH Industries, Inc.