Datawell BV RX-C4 User manual

Datawell Waverider
Receiver
Manual
RX-C4
from serial no.: 60900 and
firmware rev.: 60M02x11
March 20, 2019
Service & Sales
Voltastraat 3
1704 RP Heerhugowaard
The Netherlands
[phone]
[phone]
www.datawell.nl

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The state of the art receiver and antenna splitter used for receiving our Waveriders are
fully similar with our receiver and antenna splitter tested by the Notified Body in 2015 and
therefore compliant with our Declaration of Conformity.
Check if mains supply matches with the specifications of the device.

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Declaration of conformity
(According to EN ISO/IEC 17050-1:2004)
Document No.: Datawell_DoC_RXC4_AntSpl_1_2
Manufacturer's name: Datawell B.V.
Manufacturer's address: Zomerluststraat 4
2012 LM Haarlem
The Netherlands
Declares under sole responsibility that the product:
Product name: RX-C4 receiver, Antenna Splitter
Trade name: Datawell
Models: 230 VAC, 12 VDC, 19 inch, low/high
band
complies with the essential requirements of the following applicable European
Directives, and carries the CE marking accordingly:
RE Directive (2014/53/EU)
ROHS Directive (2011/65/EU)
and conforms with the following product standards:
RED EN 301 489-1
EN 301 489-3
EN 60950-1 (2006) +
A11 (2009) +A1 (2010) +
A12 (2011) +A2 (2013)
Supplementary Information:
This DoC applies to above-listed products placed on the EU market after:
June 13, 2017 Eric Stoker
Date Quality Assurance Manager

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Contents
1Introduction .............................................................................................. 7
2Front- and back-panel layout .................................................................. 9
2.1 Back panel layout............................................................................... 10
3Installation.............................................................................................. 11
3.1 Power supply ..................................................................................... 11
3.2 Receiving antenna ............................................................................. 11
3.3 Connecting the serial output to a PC.................................................. 12
3.4 Connecting to a local area network .................................................... 13
3.5 Grounding .......................................................................................... 13
3.6 Lightning protection............................................................................ 13
4Configuration and receiving data ......................................................... 15
4.1 Configuration...................................................................................... 15
4.1.1 Changing the frequency.............................................................. 16
4.1.2 Frequency presets ...................................................................... 16
4.1.3 Changing the receiver mode ....................................................... 16
4.1.4 Changing the network settings.................................................... 17
4.1.5 Info functions............................................................................... 18
4.2 Receiving data ................................................................................... 18
4.2.1 GPS position............................................................................... 19
4.2.2 Signal quality............................................................................... 19
4.2.3 Speaker ...................................................................................... 20
4.3 Using the web interface...................................................................... 20
4.3.1 Web interface settings page........................................................ 21
4.4 Retrieving data over a network .......................................................... 22
5Troubleshooting..................................................................................... 23
5.1 Power and fuses ................................................................................ 23
5.2 Antenna, signal quality and noise ...................................................... 23
5.3 Data interface..................................................................................... 24
6Specifications......................................................................................... 25
7Contact information............................................................................... 27
Appendix A: Buoy HF data link and range ................................................... 29
Appendix B: Output message format ........................................................... 38
Appendix C: Abbreviations ........................................................................... 39
Appendix D: Receiving antennas.................................................................. 40
Appendix E: Data server programming........................................................ 44
Appendix F: Demonstration mode................................................................ 45
Appendix G: Antenna splitter........................................................................ 48

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1 Introduction
The RX-C4 is an advanced HF link receiver that can receive all Datawell Waverider buoys
using the HXV or HVA transmission format. The HXV format is transmitted by the MkI, MkII
and MkIII generations of buoys. The MkIII generation includes the DWR-MkIII, the DWR-G
and the WR-SG,. The HVA format is transmitted by the “4-series”generation of buoys. This
includes the DWR4/ACM and the DWR4. This manual covers RX-C4’s with serial numbers
and firmware revisions as shown on the cover.
The RX-C4 is equipped with an easy to use electronic tuning system. This makes it possible to
tune exactly into a buoy frequency without the need to change the receiving crystal. The RX-C4
can be connected to a PC using RS232 or a LAN network connection. When connected using a
LAN network, the RX-C4 can be monitored and configured using a built-in web interface.
In Chapters 2,3 and 4 of this manual, the installation and operation of the RX-C4 are discussed.
Chapter 5 gives some solutions to common problems. The specifications of the RX-C4 can be
found in chapter 6.

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2 Front- and back-panel layout
Figure 2.1. RX-C4 front panel layout desktop version.
Figure 2.2. RX-C4 front panel layout 19” rack-mounted version.
The front panel contains the LCD and the buttons up/speaker ( ▲), menu/select () and down ( ).

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2.1 Back panel layout
Figure 2.3. Back panel layout AC power supply version.
Figure 2.4. Back panel layout DC power supply version.
The back panel contains the following connectors:
Socket for mains supply with fuses (AC power supply version only).
Socket for DC power supply (DC power supply version only).
Audio out for beat-note monitoring.
Female 9-pin RS232 connector.
Network connector and leds.
-green led indicates network connection.
- red led indicates network activity.
Antenna input connector.
Figure 2.5. DC power connector pinout and cable

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3 Installation
This chapter describes how to install RX-C4. To function correctly, an RX-C4 needs at least the
following:
Power supply.
Receiving antenna.
Connection to a PC using the serial port and/or a local area network.
The following paragraphs will discuss these connections as well as grounding and lightning
protection considerations.
3.1 Power supply
The AC version of the receiver must be fed from a AC power source with a voltage between
100 and 240 V. Please refer to paragraph 6 for the exact voltage and power requirements.
The customer should provide for a cord set terminated with connector type C13 according to
IEC 60320-1 and a mains plug in accordance with national standards. The RX-C4 is a class I
appliance and requires an earthed socket for connection to protective-earth.
The DC version of the receiver must be fed with a nominal voltage of 12VDC. Please refer to
paragraph 6 for the exact voltage and power requirements. The supplied power lead has 3 leads.
The blue and brown leads connect to the DC power supply. The yellow/green lead must be
connected to (safety) ground. See paragraph 2.1 for more information.
3.2 Receiving antenna
General HF link considerations
Directional Waverider buoys use a low power HF transmitter. The transmitting antenna is a
vertically polarized quarter wavelength whip. The receiving end of the link should receive as
much signal from the buoy transmitter and as little noise and interference as possible. To
achieve this the receiving antenna and -station should preferably be located at or near the coast,
see Appendix A and Appendix D for more information.
Receiving antenna location and height
The transmitter antenna is vertically polarised, therefore the receiving antenna must also be
mounted vertically. For the assembly of the antenna and adjustment of its length to the transmit
frequency see Appendix D.
Over sea the field strength does not vary significantly with the height of the receiving antenna
up to 100 m. If the receiving antenna can be located within a few tens of meters of the sea, its
height is not important.
Over land the field strength is attenuated by RF losses in the ground. For this reason it is
recommended that the antenna should be placed within a few tens of meters of the sea if
possible. If the distance from the sea is greater, the ground losses can (partially) be compensated
for by mounting the antenna at an height up to 20-30 meters. Generally, more than 20 -30m
above sea level will not improve the reception quality.
If possible mount the antenna in such a way that is has a free “sight”in the direction of the
buoy. Large structures such as embankments, ships and buildings in the direct optical path to the
buoy will attenuate the received signal.

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For interference free reception it is advisable to install the Receiving antenna as far as possible
from local interference sources such as combustion engines, electric motors and fluorescent
lamps. In general a transmitting distance of 50 Km (30 n.m.) over sea water can be attained
when the receiving antenna is located at least 100 m from interference sources mentioned. If
considerable interference is present at the location where the receiving equipment has to be
installed, the antenna should be moved to a position with lower interference. Also the use of a
directional antenna (see Appendix D) can be considered. Transmission range of the DWR-G
0.4m is less: line of sight with a handheld receiving antenna and 25 Km with a ground plane
antenna.
Installing the antenna cable
The length of the antenna cable is not critical as long as a good quality coaxial cable is used.
The supplied RG 213 cable has an attenuation of 3.5 dB/100m allowing up to 200m of cable
lengths. However, shorter cable lengths are always preferred to improve the signal to noise
ratio. Especially in signal limited situations (where signals of buoys at the edge of the normal
range must be received) the cable should be no longer than strictly necessary. Install the coaxial
cable without stretching or bending and avoid mechanical stress. With respect to routing there
are few restrictions. Although the cable is screened and not very sensitive to surrounding
electric or magnetic fields and disturbances, try to avoid routing the cable directly along power
cabling.
Be aware of the fact that reception in most areas is limited by local noise and interference. It
pays to install the antenna in such a way that distance to local sources of noise and interference
is maximized. In these situations, it is entirely acceptable to use a longer cable in order to install
the antenna further away from a source of interference.
Using a directional antenna
In case of weak signal and/or high local noise or interference the use of a directional antenna
can be considered. The sensitivity of such an antenna is 3 dB higher in the direction of the buoy.
Interference and noise generated at the landside will be attenuated by 6 dB. The combination of
gain at the front side (thus towards the buoy) and suppression of noise from the backside of the
antenna will improve the signal to noise ratio.
Using an antenna splitter
For connecting multiple receivers to a single antenna, the Datawell Antenna Splitter can be
used. This device is optimized for the buoy reception frequencies and signal levels. With the
Datawell Antenna Splitter up to six receivers can be used with a single antenna.
3.3 Connecting the serial output to a PC
Connection of the serial output to a PC is done using a standard D-SUB RS232 cable assembly.
The receiver has a nine pin D-SUB outlet of which only pins 2 and 3 carry active signals. To
prevent crosstalk issues, pins 1,6,8 and 9 are internally terminated to signal ground by a 100Ω
resistor. Pin 5 is signal ground. Normal RS232 cable length restrictions apply. RS232 ports are
becoming scarce on PC’s, in favour of USB ports. This problem may be solved with a RS232-
USB serial adapter. However, some adapter models do not offer the same data transmission
reliability as RS232 serial connections do.

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3.4 Connecting to a local area network
Connection to a local area network (LAN) is done using a straight CAT5 UTP cable. Before
connecting the receiver to a LAN, the IP address and network settings must be properly
configured. Please refer to paragraph 4.1.4. It is also possible to connect the receiver directly
to a PC. In this case, a CAT5 UTP cross cable must be used. The use of shielded or screened
CAT5 cables is not recommended. These cables can induce ground loop issues. Normal
Ethernet cable length restrictions apply.
3.5 Grounding
For correct reception of buoy signals grounding of the antenna is not necessary. The supplied
ground plane antenna takes care of its own RF reference. Also grounding of the receiver and/or
connected computer is not a remedy for all kind of noises and disturbances. Noise and trouble
free reception should be possible without any connection or reference to ground.
However from a viewpoint of safety it is recommended to connect the receiver to a safety
ground. Normally the three wire power cord will take care of this.
3.6 Lightning protection
For effective protection against lightning strike it is advisable to connect the antenna supporting
structure to a ground electrode that is suitable for lightning protection. In the case that the
building or adjoining buildings and/or mast on which the antenna is installed is already lightning
protected it is sufficient to connect the antenna supporting structure to this grounding net. Also
the antenna cable should be protected with an impulse suppressor at the point where the antenna
cable enters the building. This impulse suppressor should be grounded properly. When in doubt
leave lightning protection to skilled consultants and/or companies.

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4 Configuration and receiving data
This chapter describes how to configure the RX-C4 and receive data. For a description of the
normal operation of the RX-C4, refer to paragraph 4.2. To configure the RX-C4’s reception
frequency and receiving mode, refer to paragraph 4.1.1 and paragraph 4.1.3.
When the RX-C4 needs to be connected to a LAN, it is very important to correctly configure the
RX-C4’s network settings before connecting the receiver to a LAN. The network settings are
discussed in paragraph 4.1.4.
4.1 Configuration
All of the RX-C4 settings are accessible and configurable from the configuration menu.
The following paragraphs describe how to navigate through the configuration menu.
To navigate through the configuration menu, three buttons on the front panel are used:
the “up/speaker” button, indicated by ▲.
the “menu/select”button, indicated by .
the “down”button, indicated by .
To activate the configuration menu, push and hold down the “ ” button. After a few seconds
of holding the “” button down the receiver will enter the configuration menu as shown in
figure 4.1.
Figure 4.1. The top menu with the EXIT function selected.
This is the top menu. From here, the memory, info, frequency and network settings can be
accessed. The ▲ and buttons are used to navigate through the menu items. The currently
selected item is indicated by capital letters and “[ ]” brackets. When editing numbers (for
example when changing the reception frequency), the currently selected digit of the number is
underlined.
To select an item (or edit a digit), the button is used. By default, the [EXIT] function is
always selected. This function will save any changed settings and exit the configuration menu.
NOTE: Any settings changed using the configuration menu are only saved to the non-
volatile (EEPROM) memory by exiting the top menu. It is therefore very important to
always properly exit the top menu after changing any settings. If this is not done properly, the
settings will not be remembered after a power-loss or remote reset.

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4.1.1 Changing the frequency
In the top menu, the current reception frequency is shown. To change this frequency, use the ▲
and buttons to select the digit that needs to be changed (see figure 4.2). The selected digit is
the digit that is underlined. To change that digit, press the button, the digit will start blinking
and can now be changed using the ▲ and buttons. Press the again to select another digit.
The reception frequency can be changed in steps of 1 MHz, 0.1 MHz, 0.01 MHz, 0.001 MHz
and 0.0001 MHz.
Figure 4.2. The top menu with the 1 MHz digit of the reception frequency selected.
To save the new reception frequency to non-volatile memory, be sure to properly exit the top
menu.
4.1.2 Frequency presets
From the top menu, select the “mem” menu item to enter the frequency preset menu (see figure
4.3). From the preset menu, the “sto” options stores the current reception frequency to a preset
slot (1..6). The “rcl” options recalls a reception frequency from a preset slot (1..6).
Figure 4.3. The preset menu with EXIT selected.
To save any changes made to the preset menu to non-volatile memory, be sure to properly exit
the top menu.
4.1.3 Changing the receiver mode
The RX-C4 can receive data in the HXV format and in the HVA format. The HXV format is
transmitted by the MkI, MkII and MkIII generation of buoys. The MkIII generation includes the
WR-SG, the DWR-MkIII and the DWR-G. The HVA format is transmitted by the “MkIV”
generation of buoys. This includes the DWR4 and the GPS-DWR4.
To change the receiver mode, select the “recv” menu item on the top menu. This will bring up
the receiver menu. In the receiver menu select the “mode” menu item. Press the button to
change the receiver mode. Possible choices are HXV and HVA.
To save the new receiver mode to non-volatile memory, be sure to properly exit the top menu.

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4.1.4 Changing the network settings
From the top menu, select the “net” menu item to enter the network menu (see figure 4.4). From
the network menu, the IP address, the net mask and the gateway address can be configured.
Also, the web interface password can be reset to the default value from this menu. For more
information about the web interface password, see paragraph 0.
The RX-C4 only supports static IP addresses. Dynamic (DHCP) addresses are not supported. It
is therefore important to choose an IP address that is not used by any other device on the LAN.
When in doubt about the IP address or other network settings, please consult the local system
administrator.
To save the new network settings to non-volatile memory, be sure to properly exit the top menu
after changing any of the values in this menu.
Figure 4.4.The network menu with EXIT selected.
To change the IP address:
Select the “ip” menu item to enter the IP address menu. To change the IP address, use the ▲
and buttons to select the number (byte) of the address that needs to be changed (see figure
4.5). The selected number is the number that is underlined. To change the number, press the 
button, the lower digit of the number will start blinking and can now be changed using the ▲
and buttons. Press the again to select another number. The “default” menu item will set
the IP address to the default value of 192.168.0.101.
Figure 4.5. Editing an IP address, net mask or gateway address.
To change the net mask:
Select the “mask” menu item to enter the net mask menu. To change the net mask, use the ▲
and buttons to select the number (byte) of the net mask that needs to be changed (see figure
4.5). The selected number is the number that is underlined. To change the number, press the 
button, the lower digit of the number will start blinking and can now be changed using the ▲
and buttons. Press the again to select another number. The “default” menu item will set
the net mask to the default value of 255.255.255.0.

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To change the gateway address:
Select the “gway” menu item to enter the gateway address menu. To change the gateway
address, use the ▲ and buttons to select the number (byte) of the gateway address that needs
to be changed (see figure 4.5). The selected number is the number that is underlined. To change
the number, press the button, the lower digit of the number will start blinking and can now be
changed using the ▲ and buttons. Press the again to select another number. The “default”
menu item will set the gateway address to the most likely address based upon the current IP
address and the net mask (the IP address and net mask are “and” together to form a base
address, the gateway is then supposed to be at this base address + 1).
To reset the web interface password:
Select the “rst_pass” menu item to reset the web interface password to its default value. For
more information about the web interface password, see paragraph 4.3.1.
4.1.5 Info functions
From the top menu, select the “recv” menu item to enter the receiver menu. Then, from the
receiver menu, select the “info” menu item to enter the information menu
The info menu shows some miscellaneous receiver statistics that may be useful in the case of
transmission problems. To exit the information menu, press the button.
The info menu has two “screens”that can be rotated through by pressing the ▲ and buttons.
The two “screens” are:
Act. frequency
This screen shows the actual frequency at which the buoy is currently being received. The actual
frequency may be different from the defined reception frequency. This is due to frequency
errors caused by, for example, temperature drifting in the buoy transmitter. This is normal
behaviour and no reason for concern.
Signal status
This screen shows the quality of the incoming signal by two parameters.
FER is the frame error rate; it tells how many percent of the incoming data vectors have one or
more bit errors. IFD is a measure for the frequency deviation of the signal in Hz.
Under normal circumstances FER < 5% and IFD < 15Hz (approximately).
4.2 Receiving data
When the receiver is not in the configuration mode, the status of the data receiving process is
shown on the display (see figure 4.6). The display shows the current receiver mode (see
paragraph 4.1.3), receiver status and signal quality.
To correctly receive and decode data, the receiver must first “synchronize” with the buoy signal.
The status of this process is shown by the messages on the display. There are four messages
defined:
“synchronizing”
This message indicates that the receiver is synchronizing. This message appears after the
receiver has been switched on, after the receiving frequency has been changed, after the
receiver mode has been changed or when the receiver has lost the buoy signal.
“heave: 153 cm”
This message (see figure 4.6) indicates that the receiver is correctly synchronized and
receiving data. The heave value is the actual, real-time vertical displacement of the buoy.

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“heave: ??? cm”
This message indicates a transmission error.
Figure 4.6. Receiving data.
Normally, after power up or loss of signal, the receiver will display “synchronizing” for some
time. When the quality of the received signal is high enough, the “heave” messages will be
displayed. If the signal quality becomes too low, the receiver will try to resynchronize to the
buoy signal.
NOTE: The process of synchronization can take anything between 30 seconds to several
minutes. The time needed to reach synchronization depends on several factors like
signal-strength, interference, noise bursts and type of buoy.
4.2.1 GPS position
When the buoy being received is equipped with a GPS module, the GPS position of the buoy is
shown on the display. The GPS position message is “rotated” with the heave message according
to the scheme shown in figure 4.7.
Figure 4.7. Heave message and GPS message rotating scheme.
Note that the update rate of the GPS position is defined by the received buoy. Please refer to the
buoy documentation for more information.
4.2.2 Signal quality
When displaying heave, a signal quality bar graph is shown on the display, see figure 4.6. The
signal quality indication is derived from the “frame error rate”(FER) parameter. A full-scale
deflection of this bar indicates that no errors are detected in the incoming data (FER = 0%)
while no deflection at all indicates that all received data contains errors (FER = 100%).

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4.2.3 Speaker
The speaker is used to get an audible indication of the signal quality. A 1500 Hz frequency-
modulated beat-note should be heard against a clean background (none or clean noise without
any sign of interference or noise bursts).
The speaker can be switched on and off by pressing the “▲ ” button
NOTE: If the signal is heard clearly through the speaker but the receiver fails to
synchronize, check if the receiver mode is set correctly (see paragraph 4.1.3).
4.3 Using the web interface
The RX-C4 has an embedded web interface available at TCP/IP port 80. The embedded web
interface allows remote monitoring and configuration of the RX-C4 receiver.
To use the web interface, the RX-C4 must be properly configured (see paragraph 4.1.4) and
connected to a LAN (see paragraph 3.4).
To access the web server from a computer, enter the following address in the address bar of the
web browser:
http://<RX-C4 IP address>
For example, when the RX-C4 IP address is the default of 192.168.0.101:
http://192.168.0.101
Figure 4.8. RX-C4 web interface home page.
This will bring up the RX-C4 web interface home page as shown in figure 4.8. The home page
shows the current receiver status and the current server status (see paragraph 4.4). The menu on
the right gives access to the “settings” page and the “about” page.
The frequency correction value is a measure of the frequency deviation of the buoy transmitter.
The frame error rate gives an indication of the signal quality. A value of 0% indicates that all
vectors are decoded without any errors; signal quality is perfect. A value of 99% indicates that
almost every vector contains errors; signal quality is bad.