Autonnic A4032 User manual

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A4032 COMPASS PICK-UP USER MANUAL
October 2022
A4032 manual 13
Hardware version 3
PCB 7319-6
PCB 7322-3
Software version V040

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Table of Contents
1 Description
2 Installation
2.1 Mounting
2.2 Power supply
2.3 Connection
2.3.1 Compass to a NMEA-0183 instrument
2.3.2 Compass to a PC serial port
3 Calibration
4 NMEA-0183 Serial data
Input Commands and Output Data
5 References

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1. Description
The Autonnic A4032 is a complete sensing and processing sub-system for
a compass indicating system which gets its heading information from a
main or ‘master’ compass. It derives its output from the position of the
powerful permanent magnet inside the main compass.
The A4032 contains a dual-axis fluxgate magnetometer surrounded by
high-precision interface circuits which, together with the special
clockwise/anticlockwise and a sequence to null offsets allow a
microprocessor to acquire a binary value from the two orthogonal sensors
of the direction of the field created by the main compass. The processor
calculates the vector from these values and then presents the data in a
manner which has been requested. Such requests alter the frequency of
the data, the degree of filtering and the offset value. Calibration
sequences can also be commanded.
The embedded software can be uploaded by command so that special or
updated versions releases can be put into the A4032 to replace the
previous software. These data files may be sent from Autonnic by email
or downloaded from our website.
2 Installation
2.1 Mounting
The A4032 is fixed to the base of the ship’s compass using the fixing holes
shown in the data sheet. The cable hangs down directly from the labelled
side of the housing.
It does not matter which way it faces as the azimuth can be set to North
at any time. But some installers prefer to align the internal sensor to
magnetic North and to facilitate this the A4032 is provided with an
alignment mark and a rotatable housing assembly.
NOTE 1 The heading data is suppressed when the field is low –see the
RXY command in section 4.2.14
NOTE 2 The heading data is also suppressed when the field is high. See
4.2.14
2.2 Power supply
The compass is compatible with any DC power supply of between 8 and
30 V but note that for nominal 24V operation a 1W resistor of 330ohms
should be inserted in the supply wire. This applies to any power supply of
greater than 18V. Note that the maximum voltage must not be greater
than 30V.
Typical supply current during operation is approx. 25mA. The compass is
protected against reversed polarity.

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Care should be taken to make sure the compass is not situated too close
to the power supply, as it’s accuracy may be affected by either the iron in
the mains transformer, or by magnetic field ‘noise’ from a switching power
supply. But this is unlikely as the A4032 will be mounted on a fixed
compass which should have been sited correctly.
Note that the output from the A4032 takes several seconds to stabilize
after power is applied; the time taken depends on the damping settings.
There is a command - see section 5 –which can be used to suppress the
output after power-up.
2.3 Connection
Check the datasheet that this table is valid for your version.
Wire
Colour
Type
Function
1
Red
Power
+8 to +30V note 1
2
Blue
Signal
NMEA OUT+
3
Green
Signal
NMEA IN+
4
Yellow
Signal
NMEA IN-
5
Screen
Power and Signal
GROUND 0V
Note 1 For nominal 24V operation a 1W resistor of 330ohms should be
inserted in the supply wire.
2.3.1 Compass to a NMEA-0183 instrument
The hardware on which the NMEA-0183 standard is based on is a balanced
serial protocol called RS422. This means that two wires are need for send
and two for receive.
Fig 1
Note that the GND wire is used for the current return path. This might be
shared with the NMEA- wire in some installations.
External NMEA device
6 NMEA OUT +
4 NMEA IN+
3 NMEA IN-
5 GND
NMEA current
source
+
-

5
A5022
COM PORT D
CONNECTOR
2
3
5
4 NMEA IN +
3 NMEA IN -
5 GND
6 NMEA OUT +
7 GND
+
POWER
SOURCE
-1 +8-30V
2.3.2 Compass to a PC serial port
In many cases the wires can be joined directly as shown in Fig 2.
Alternatively use the Autonnic A3036 serial interface unit.
Fig 2
3 Calibration
3.1 Basic Calibration Operation
Sensor
Factory
Default
(Fixed)
Calibration
Table
Candidate
Values Table
Raw
Magnetic
Angle
Interpolation OUTPUT
Offsetzero
0CV PCV
AHD
SCV
RXY RCV
0CV
0PV
FD0
Fig 3

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This diagram is intended to illustrate the operation of commands involved
in the calibration process.
The Calibration Sequence is:
•Send 0CV
•Turn the compass so it points to 0 i.e. it is pointing magnetic North
•Rotate the A4032 until the output angle is zero
•Send a sequence of PCV commands while the compass is rotated
–one every 10deg
•Send SCV to update the table used for correction
3.2 Use of PC Calibration Software Tools
This describes the operation of the two Autonnic A4032 Calibration
software tools
Factory Utility 1.13 and
P6033 Calibration Tool V1.02
[Note that the Calibration Tool is only for use with A4032 firmware
v040 and later]
This normally is delivered packed as a zip file: A4032 Cal tool kit.zip
This must first be unpacked so it can be used. Once that is done the files
can be installed.
Open the Factory Utility 1.13 directory and use the file called setup.exe
This is likely to cause your PC to advise against it –but ignore the
warnings and complete the installation
Similarly, open the P6033 Calibration Tool V1.02 directory and use the file
also called setup.exe to install it.
This is also likely to cause your PC to advise against it –but, again, ignore
the warnings and complete the installation.
Hardware notes:
1The A4032 is to be attached to a magnetic compass which itself can
be rotated while the A4032 does not move relative to the
compass so that, at all times, the A4032 data represents the
angle of the magnet of the Compass.
2The PC will have a port assigned to the USB-RS232 cable attached
to the A4032 and the number of this port must be found from
the Device Manager Windows utility. Eg COM 6

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Once this is operating the software can be used as follows:
Note that the [bracket] means the button on the screen of that name.
1Connect the A4032 to the Autonnic Factory Utility
V1.12 with the correct port selected (see note
above) and use the [CONFIG] button to put a
command string into the send panel on the screen
which looks like this:
PATC,IIHDG,CFG,020
Make sure that the field is 020 as above –edit it
so that it does. Then press [SEND] so that the
message now uses the HDM format which you
can see in the scrolling window.
2The press [SCI] and adjust the field at the end of the
command so it shows the calibration angle
interval you wish to use - usually 10 and then
press [SEND]
3Close the port (but leave the program running) and
open the Calibration Tool V1.02. Open the correct
comm port to connect. Then adjust the Compass
so the needle is at 0.0 and adjust the A4032 by
rotating it so it too reads 0.0. Then press
[START]
4Click [Calibrate 0] and this button changes to
‘Calibrate 10’. Turn the Compass so that it points
to 10deg and press [Calibrate 10] which then
changes to ‘Calibrate 20’ and so on. The output
of the A4032 appears on the screen but will not
exactly match the heading –that is purpose of
calibration.

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5The sectors on the screen change colour as each
point is set.
6When the button says ‘Calibrate 360’ DO NOT press
it but close the com port with [Close com port].
7On the Autonnic Factory Utility V1.12 screen
reconnect the port. Then press [SCV] to transfer
the points to the internal calibration tables within
the A4032. Which is now calibrated.
8Note that if you don’t like a point you can go back to
it and reset it using the [PCV] button but any
change must be transferred with [SCV]
9If you do not want to continue with the HDM format
use the [CFG] button to load the configuration
string into the text window and edit it to give you
the format you want according to the details in
section 4.2.4
Use the buttons on the PC screen to use either the calibrated table [SCV]
or the uncalibrated values [0CV].

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4 NMEA-0183 Serial data
4.1 General Format
The serial output format is: 4800 Baud, 8 data bits, 1 stop bit, no parity
but note that it is not NMEA-0183 at the physical level –solely in the
meaning of the data.
The compass sends information using the standard NMEA-0183 sentence
‘HDG’: Magnetic Heading, Deviation, and Variation. But note that the
information of Deviation and Variation is not sent and so blank fields are
defined by consecutive commas. In the A4032 the sentence may have one
of several forms typically of the general form:
$HCHDG,hhh.h,,,,*ssss<CR><LF>
Note that the first character is typically $ but the A4032 will respond
correctly even if it is missing.
4.2 List of Command in V040 of the software
4.2.1
0CV
Factory default calibration values;
zero heading offset;
4.2.2
0PV
Set the calibration candidate table
to factory default values
4.2.3
AHD
Set heading offset
4.2.4
CFG
Configure NMEA sentence output
format
4.2.5
DHD
Set heading damping value
4.2.6
DLY
Set power up delay
4.2.7
FDO
Factory default: fluxgate heading
output rate; fluxgate damping
factor; last calibration error code
4.2.8
INV
Set normal / inverted compass
mount
4.2.9
PCV
Read current heading, calculate
and program calibration value
4.2.10
RCV
Read calibration values

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4.2.11
RHD
Read heading damping value
4.2.12
RHO
Read heading offset
4.2.13
RID
Read device serial number
4.2.14
RXY
One shot read of raw ADC values:
X, Y, REF,Vector,Temperature
4.2.15
SCV
Copy calibration bank 2 to bank 1
4.2.16
SR
Read software version
4.2.17
TMP
Set temperature output period
4.2.18
TXP
Set NMEA output period
4.2.19
TXY
Toggle RXY
4.2.20
UPLOAD
Enter bootloader
4.2.1 0CV
$PATC,IIHDG,0CV<CR><LF>
Sets the following:
Output rate u= 100 milliseconds (10 updates/second),
output damping d= 50 percent
heading offset f= 0 degrees.
Calibration Table to Factory Settings (i.e. not calibrated)
4.2.2 0PV
$PATC,IIHDG,0PV<CR><LF>
Sets the Candidate Calibration Table values to Default (see Fig 3)
4.2.3 AHD
$PATC,IIHDG,AHD,fff.f<CR><LF>
Set heading:
Forces the heading to a certain value by supplying an offset which is
stored and used thereafter.
Where f is in degrees with a valid range of 000.0 to 359.9
When f = 000.0 the result is the same as pressing switch 2 –see 1.3.
Do not use this when calibrating.

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4.2.4 CFG
$PATC,IIHDG,CFG,ab<CR><LF>
Configures the output sentence structure and type.
[Replies with the standard acknowledge sentence
$PATC,HCHDG,ACK<CR><LF>]
Where 'a' specifies the heading of the output sentence as follows:
a=0 : $HCHDG,hhh.h,,,,<CR><LF>
a=1 : $HCHDT,hhh.h,T<CR><LF>
a=2 : $HCHDM,hhh.h,M<CR><LF>
a=3 : $HCHCC,hhh.h<CR><LF> - default
a=4 : $HEHDT,hhh.h<CR><LF>
a=5: no heading data sent
hhh.h is the compass heading in degrees
(this compass heading field will be omitted when auto-calibration is in
process)
and 'b' is sentence end structure as follows:
b=0 : direction sentence will NOT include checksum nor unit ID serial
number.
e.g. $HCHDG,hhh.h,,,,<CR><LF>
b=1 : direction sentence will include a checksum.
e.g. $HCHDG,hhh.h,,,,*cc<CR><LF> (cc is the checksum)
b=2 : include the serial number.
e.g. $HCHDG,hhh.h,,,,*ssss<CR><LF> (ssss is the unit’s
serial number)
4.2.5 DHD
$PATC,IIHDG,DHD,ddd.d<CR><LF>
Set the internal filtering: ('damping')
Valid range for d is 2 to 30 with the default set at 15.

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4.2.6 DLY
$PATC,IIHDG,DLYn.n<CR><LF>
Startup Delay
Sets a delay from Power-up to the transmission of the first output
sentence where n.n is in seconds with a maximum of 6.5
4.2.7 FD0
$PATC,IIHDG,FD0<CR><LF>
This is very similar to 0CV except that the calibration tables are
unchanged.
4.2.8 INV
$PATC,IIHDG,INV,a<CR><LF>
Set device mounting preference
where :
a=0 device mount normally (i.e. top of fluxgate pointed upward)
a=1 device mount inertly (i.e. top of fluxgate pointed downward)
The A4032 replies with the standard acknowledge sentence
4.2.9 PCV
$PATC,IIHDG,PCV,aa0<CR><LF>
This command should be used only after sending the 0CV command.
The PCV command has the following format:
where angle is in degrees 0 <= aa0 <= 360 and must be a multiple of
10°.
To perform full calibration:
$PATC,IIHDG,PCV,0
$PATC,IIHDG,PCV,10
$PATC,IIHDG,PCV,20
…
…
$PATC,IIHDG,PCV,340
$PATC,IIHDG,PCV,350
NOTE: $PATC,IIHDG,PCV,360 is not supported.

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If the calibration is successful and within allowed limits ACK is sent back
otherwise a NACK is sent back:
$PATC,IIHDG,PCV,340
$PATC,HCHDG,ACK successful
or
$PATC,IIHDG,PCV,322
$PATC,HCHDG,NACK not successful because angle not multiple
of 10°.
or
$PATC,IIHDG,PCV,320
$PATC,HCHDG,NACK not successful because at 320° the P6033
thought it was at < 290° or > 350°. It must be within +/-30°
There is no checking by the P6033 to make sure all 37 points have been
manually calibrated. This should be done at a higher level by the PC utility
sending the PCV commands. The points can be calibrated in any order and
recalibration of any point can be done at any time provided the pickup
thinks it is within +/-10° of the point.
By implication an error of greater than +/-10° cannot be corrected.
4.2.10 RCV
$PATC,IIHDG,RCV<CR><LF>
This command is to read the calibration table values and the response is
in the form of the example shown below:
$TCF,0,0000,071C,0E38,1554,
$TCF,1,1C70,238C,2AA8,31C4,
$TCF,2,38E0,3FFC,4718,4E34,
$TCF,3,5550,5C6C,6388,6AA4,
$TCF,4,71C0,78DC,7FF8,8714,
$TCF,5,8E30,954C,9C68,A384,
$TCF,6,AAA0,B1BC,B8D8,BFF4,
$TCF,7,C710,CE2C,D548,DC64,
$TCF,8,E380,EA9C,F1B8,F8D4,
4.2.11 RHD
$PATC,IIHDG,RHD,nn<CR><LF>
Request internal filter response
Where nn is the damping value within the range 0 to 30

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4.2.12 RHO
$PATC,IIHDG,RHO<CR><LF>
$PATC,IIHDG,RHO,nnn.n<CR><LF>
Where nnn.n is the heading offset Note that leading zeros are suppressed
eg 0.0
4.2.13 RID
$PATC,IIHDG,RID<CR><LF>
Request the serial number:
A special proprietary reply sentence follows:
$PATC,IIHDG,RID,ssss<CR><LF> where ssss is the serial number in
ASCII decimal.
4.2.14 RXY
$PATC,IIHDG,RXY<CR><LF>
Returns the magnetic sensor values of X, Y, the reference voltage and the
field vector and Temperature in decimal with the range 0 to 4095.
$RXY,xxxx,yyyy,vvvv,tttt,*cc<CR><LF>
A value of zero field is represented by 0. The internal analogue zero is not
sent as it has already been corrected for.
The main purpose is to check that the magnetic field is not so high that it
overloads the sensor (by the strong field of the compass magnet to which
it is attached) nor is so low that the output will be noisy.
See also 4.2.21 for the MFE field strength warning message details.
4.2.15 SCV
$PATC,IIHDG,SCV<CR><LF>
Copy calibration data into the Calibration Table to be used for all
subsequent outputs. This is why is must be cleared before calibration so
that the data used for calibration is ‘raw’ magnetic data.

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4.2.16 SR
$SR <CR><LF>
Read device firmware release
A typical response from a unit is as follows:
$SR,A5024,016,02<CR><LF>
showing the release is 016.
4.2.17 TMP
$PATC,IIHDG,TMP,rr
Set rate at which temperature data is sent.
where rr is the rate from 0 (default) to 30.
$PATC,IIHDG,TMP,0 disables the temperature display feature
$PATC,IIHDG,TMP,1 sets the temperature display rate to the fastest
rate of once a minute
$PATC,IIHDG,TMP,10 sets the temperature display rate to a value in
between, in this case, once every 10 minutes.
$PATC,IIHDG,TMP,30 sets the temperature display rate to the slowest
of once every 30 minutes
When the set temperature display rate command is issued the
temperature is displayed within 1 second and then repeats at the new rate
set.
The rate setting is stored in non-volatile memory.
The ouput of temperature has the following format:
$TEMP,tt
OR
$TEMP,tt*cc if checksum is enabled in HCHDM heading output display
where cs is checksum
Where tt is temperature and has the following range and format:
-20 to 70
Leading zeros suppressed. Negative temperatures displayed with '-'.
E.g.: -10, -9 etc..
Zero and positive temperatures displayed purely with
digits. E.g. 0, 9, 19 etc..

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4.2.18 TXP
$PATC,IIHDG,TXP,uuuu<CR><LF>
Set the Output update period:
Valid range is u=100 (default) to 2500 milliseconds. This is limited by the
maximum data rate of NMEA-0183 output at 4800 baud.
4.2.19 TXY
$PATC,IIHDG,TXY<CR><LF>
Toggle RXY
This command sets a flag to enable the transmission of the data of the
RXY command continuously interleaved with the heading. By sending the
command again the flag is cleared; it is also cleared on power-up.
4.2.20 UPLOAD
This command is used by Autonnic’s updater software which runs under
Microsoft Windows. It is used to send .aeh files to install a new version of
firmware.
4.2.21 Out-of-range output
Interleaved with the normal data there is a special message sent every
500ms if the field strength is deemed to be out of range.
Typical examples are:
Low:
$PATC,HCHDG,MFE,119,LOW*65 interleaved with $HCHCC,*6F
High:
$PATC,HCHDG,MFE,1652,HIGH*06 interleaved with $HCHCC,*6F
Where the value following the MFE is a representation of the field
strength.
5 References
A4032 data sheet
NMEA-0183 specification
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Autonnic Research Ltd Tollesbury Essex CM9 8SE UK
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