HydroLynx Systems 5052RD-K User manual

HydroLynx Systems, Inc.
Model 5052RD-K
ALERT2 Receiver/Decoder
Instruction Manual
Document No: A102688
Document Revision Date: February, 2020

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 2 A102688
Receiving and Unpacking
Carefully unpack all components and compare to the packing list. Notify HydroLynx
Systems immediately concerning any discrepancy. Inspect equipment to detect any
damage that may have occurred during shipment. In the event of damage, any claim for
loss must be filed immediately with the carrier by the consignee. If the equipment was
shipped via Parcel Post or UPS, contact HydroLynx Systems for instructions.
Returns
If equipment is to be returned to the factory for any reason, call HydroLynx between
8:00 a.m. and 4:00 p.m. Pacific Time to request a Return Authorization Number (RA#).
Include with the returned equipment a description of the problem and the name, address,
and daytime phone number of the sender. Carefully pack the equipment to prevent
damage during the return shipment. Call HydroLynx for packing instructions in the case
of delicate or sensitive items. If packing facilities are not available, take the equipment to
the nearest Post Office, UPS, or other freight service and obtain assistance with
packaging. Please write the RA# on the outside of the box.
Warranty
HydroLynx Systems warrants that its products are free from defects in material and
workmanship under normal use and service for a period of one year from the date of
shipment from the factory. HydroLynx Systems' obligations under this warranty are limited
to, at HydroLynx's option: (I) replacing; or (ii) repairing; any product determined to be
defective. In no case shall HydroLynx Systems' liability exceed product's original
purchase price. This warranty does not apply to any equipment that has been repaired or
altered, except by HydroLynx Systems, or that has been subjected to misuse, negligence,
or accident. It is expressly agreed that this warranty will be in lieu of all warranties of
fitness and in lieu of the warranty of merchantability.
Address
HydroLynx Systems, Inc.
950 Riverside Pkwy., Suite 10
West Sacramento, CA 95605
Phone: [phone]
Fax: [phone]
E-mail: [email protected]m
Copyright 82017 by HydroLynx Systems, Inc.

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 3
TABLE OF CONTENTS
SECTION NO. PAGE NO.
1.0 INTRODUCTION.......................................................................................................6
1.1 General Description........................................................................................6
1.2 Equipment Included........................................................................................6
1.3 Specifications .................................................................................................6
2.0 INSTALLATION.........................................................................................................7
2.1 Site Selection..................................................................................................7
2.1.1 Antenna ............................................................................................7
2.1.2 5052RD-K.........................................................................................7
2.2 Connections....................................................................................................7
2.2.1 Option 5052RD-OP1 ALERT1 Receiver/Decoder Connections........7
2.2.2 Option 5052RD-OP2 ALERT2 Transmit Connections.......................7
2.3 Radio Frequency Selection.............................................................................8
2.3.1 ALERT2 Receive Radio Frequency Selection ..................................8
2.3.2 ALERT1 Receive Radio Frequency Selection ..................................9
2.3 Mounting.........................................................................................................9
3.0 THEORY OF OPERATION .....................................................................................10
3.1 Fused DC input.............................................................................................10
3.2 Power On Light.............................................................................................10
3.3 Radio: Tone and Squelch.............................................................................10
3.3.1 ALERT2 Receive Radio..................................................................10
3.3.2 ALERT1 Receive Radio..................................................................11
3.4 Front Panel LEDs.........................................................................................11
3.4.1 ALERT2 LEDs ................................................................................11
3.4.2 ALERT1 LED ..................................................................................11
3.4.3 ALERT1 SPEAKER ........................................................................11
3.5 Input/Output..................................................................................................11
3.5.1 ALERT2 Decoder Console..............................................................11
3.5.2 ALERT2 Decoder Output................................................................11
3.5.3 ALERT1 Decoder Output................................................................12
3.5.4 ALERT2 Transmit Input ..................................................................12
4.0 Programming...........................................................................................................13
4.1 ALERT2 Decoder Programming...................................................................13
4.1.1 ALERT2 Decoder Enable Changes ................................................13
4.1.2 ALERT2 Decoder Login Password Change....................................13
4.1.3 ALERT2 Decoder IP Address Change............................................13
4.1.4 ALERT2 Decoder Network Time Sync............................................16
4.1.5 ALERT2 Decoder Network Client Connections...............................17
4.1.6 ALERT2 Decoder SSH port change................................................18
4.1.7 ALERT2 Decoder Host Name.........................................................18
4.1.8 ALERT2 Decoder Name Servers and Host Names ........................19
4.2 ALERT1 Decoder Programming...................................................................20
4.2.1 ALERT1 Decoder IP Address Change............................................20
4.2.2 ALERT1 Decoder Login Password Change....................................24
5.0 TESTING.................................................................................................................26
5.1 RF Antenna Test ..........................................................................................26

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 4 A102688
5.2 Network Test ................................................................................................26
5.3 ALERT2 Data Out.........................................................................................27
5.4 ALERT2 Data Log ........................................................................................27
5.5 ALERT1 Data Out for OP1 ALERT1 Receiver/Decoder Option....................28
6.0 FORMS AND DRAWINGS......................................................................................29

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 5
Model 5052RD-K Receiver/Decoder Front Panel with OP1 ALERT1 Receiver/Decoder Option
Model 5052RD-K Receiver/Decoder Back Panel with OP1 ALERT1 Receiver/Decoder Option

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 6 A102688
1.0 INTRODUCTION
1.1 General Description
The Model 5052RD-K Receiver/Decoder receives ALERT2 radio data transmissions from
remote sites and provides a serial and TCP/IP data output for the base station computer.
The Receiver and Decoder are combined in a single desktop enclosure. Rack mount
brackets are included.
Model 5052RD-OP1 ALERT1 Receiver/Decoder Option receives ALERT1 radio data
transmissions from remote sites and provides a TCP/IP data output to the base station
computer. The ALERT1 Receiver and Decoder are mounted inside the 5052RD-K
Receiver/Decoder desktop enclosure.
Model 5052RD-OP2 ALERT2 Transmit Option transmits ALERT2 radio data packets to
remote sites using an additional transmit radio with its own antenna connector. The
ALERT2 Encoder and transmit radio are mounted inside the 5052RD-K
Receiver/Decoder desktop enclosure. A GPS antenna and cable are included.
ALERT2 technology has been licensed from Blue Water Design LLC.
1.2 Equipment Included
5052RD-K
Rack mount brackets
1.3 Specifications
Enclosure: Desktop, 19 in. rack mount brackets included
Radio: ALERT2 RX Ritron DTX-145, VHF
OP1 ALERT1 RX Ritron DTX-145, VHF
OP2 ALERT2 TX Maxon SD-125VE, VHF
Power Required: 12 Vdc
Power Connector: 3 pin MS male
Fuse: 5 Amps
Antenna Connector: ALERT2 RX BNC male
OP1 ALERT1 RX BNC male
OP2 ALERT2 TX BNC male
ALERT2 GPS SMA female
Console Connector: DB9 male
Data Connector: ALERT2 RJ45 female, DB9 female
OP1 ALERT1 RJ45 female, DB9 female
Data Output: ALERT2 IND Decoder Format
ASCII (port 4200) or Binary (port 4201)
OP1 ALERT1 ASCII and Binary (port 2101)
Data Input OP2: ALERT2 IND Encoder Format (port 4202)
Operating temperature: -40 to 60 °C
Size: 17 in. x 13 in. x 3.5 in.
Weight: 13 lbs.

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 7
2.0 INSTALLATION
2.1 Site Selection
2.1.1 Antenna
The receiver antenna should be installed at an elevation that is as high as practical. If
possible, install the antenna onto a radio tower, tall building, or other tall structure. Refer
to Radio Path Survey.
2.1.2 5052RD-K
The 5052RD-K ALERT2 Receiver/Decoder enclosure should be located near the antenna
tower to reduce the length of the RF transmission line and the associated RF signal loss.
It is recommended that a lightning arrestor with ground lug (optional) be placed between
the ALERT2 receiver back panel BNC connector and the antenna to protect against
lightning damage.
2.2 Connections
All wiring connections are located on the back panel.
!Connect the ALERT2 RX antenna cable to the ALERT2 RX BNC female connector.
!Attach the ground screw to earth ground using a #6 stranded copper wire. The ground
lug is provided on the ground screw.
!Attach a computer network cable to the ETHERNET RJ45 ALERT2 connector.
!Attach a computer serial cable to the SERIAL DB9 female ALERT2 connector.
!Connect the AC power supply to the 3-pin 12VDC connector. For best results, connect
the power supply to a battery backed system (UPS).
2.2.1 Option 5052RD-OP1 ALERT1 Receiver/Decoder Connections
!Connect the ALERT1 RX antenna cable to the ALERT1 RX BNC female connector.
An external antenna cable splitter can be used to share the same receive antenna.
!Attach a computer network cable to the ETHERNET RJ45 ALERT1 connector.
!Attach a computer serial cable to the SERIAL DB9 female ALERT1 connector.
2.2.2 Option 5052RD-OP2 ALERT2 Transmit Connections
!Connect the ALERT2 TX antenna cable to the ALERT2 TX BNC female connector.
!Connect the ALERT2 GPS antenna cable to the GPS SMA female connector.

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 8 A102688
2.3 Radio Frequency Selection
If the ALERT2 receive radio is programmed with several frequencies, remove the
5052RD-K ALERT2 Receiver/Decoder top cover to change radio frequencies.
2.3.1 ALERT2 Receive Radio Frequency Selection
The ALERT2 receive radio frequency is selected on the ALERT2 demodulator board
circular DIP switch S1 with the yellow center. Switch positions 0 to 7 correspond to radio
channels 1 to 8. The photo below shows switch position 4 which is the radio channel 5.

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 9
2.3.2 ALERT1 Receive Radio Frequency Selection
The ALERT1 receive radio
frequency is selected on the 6
position DIP switch inside the
radio. You must remove the
radio cover to access this
switch.
Use the radio frequency label
for the switch positions. The
photo below has radio channel
2 selected.
2.3 Mounting
The 5052RD-K is designed for "desktop" or rack mount installation.
RX TX 1 2 3 4 5 6 SW
1 169.5000 169.5000 X X X X X X ON
OFF
2 170.2750 170.2750
X
X X X X X ON
OFF
3 170.3000 170.3000 X
X
X X X X ON
OFF
4 171.0500 171.0500
X X
X X X X ON
OFF
5 171.1250 171.1250 X X
X
X X X ON
OFF
6 171.8250 171.8250
X
X
X
X X X ON
OFF
7 171.9000 171.9000 X
X
X
X X X ON
OFF
8 171.9250 171.9250
X X X
X X X ON
OFF

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 10 A102688
3.0 THEORY OF OPERATION
The 5052RD-K ALERT2 Receiver/Decoder receives ALERT2 Airlink Protocol audio
signals from the ALERT2 receive radio and decodes these signals into ALERT2
Demodulator & Decoder ASCII and Binary Asynchronous Serial Interface formats.
ALERT2 decoder output is through the back panel ETHERNET RJ45 network or SERIAL
DB9 female ALERT2 serial connectors.
The ALERT2 decoder output is logged on an SD card which can be accessed through
the ALERT2 Decoder Console.
The Receiver/Decoder is powered by a fused 12Vdc power input from a 5030-PS power
supply (optional) or 5081-18 12 Vdc 18 AmpHr battery (optional) with 5030-8 battery
charger (optional). It is recommended that the power supply be connected to a UPS
(Uninterruptible Power Supply) to prevent loss of data during power outages. A power
LED on the front panel is on when power is connected. The power input fuse is mounted
on the back panel.
The Model 5052RD-OP1 ALERT1 Receiver/Decoder Option receives ALERT1 audio
signals from the ALERT1 receive radio and decodes these signals into ALERT1 ASCII
and Binary formats. ALERT1 decoder data output is through the back panel ETHERNET
RJ45 network or SERIAL DB9 female ALERT1 serial connectors.
The Model 5052RD-OP2 ALERT2 Transmit Option receives ALERT2 IND Encoder &
Modulator Asynchronous Binary Serial Interface commands from a base station computer
through the back panel ETHERNET RJ45 ALERT2 network connector and transmits
ALERT2 Airlink Protocol audio tones through the ALERT2 transmit radio.
3.1 Fused DC input
Fuse is 5 amps.
CAUTION: Before replacing the fuse, always unplug DC power supply.
3.2 Power On Light
The power light is lighted whenever DC Power is applied. Check the fuse if the light is off
when the unit is plugged into DC Power.
3.3 Radio: Tone and Squelch
3.3.1 ALERT2 Receive Radio
The tone amplitude and squelch levels are factory set.
The audio output is 375 mV RMS with a DC offset or bias of < 3.3 Vdc.

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 11
The ALERT2 receive radio operates unsquelched.
3.3.2 ALERT1 Receive Radio
The tone amplitude and squelch levels are factory set.
Tone amplitude is 800 mV.
Squelch is set to -113 dB with no receiver amplifier, -106 dB with a receiver amplifier.
3.4 Front Panel LEDs
3.4.1 ALERT2 LEDs
Two LEDs on the front panel turn on when radio signals are received (BIT SYNC) and
decoded (FRAME SYNC). Both LEDs must turn on for a valid ALERT2 receive signal.
3.4.2 ALERT1 LED
The ALERT1 Data LED on the front panel flashes when ALERT1 radio signals are
received when the Model 5052RD-OP1 ALERT1 Receiver/Decoder Option is installed.
3.4.3 ALERT1 SPEAKER
The ALERT1 radio speaker is turned on when the toggle switch is in the down position
(towards the word SPEAKER) when the Model 5052RD-OP1 ALERT1 Receiver/Decoder
Option is installed.
3.5 Input/Output
3.5.1 ALERT2 Decoder Console
The ALERT2 decoder can be programmed using the console interface. Program changes
include the IP address, NTP servers, Decoder output clients.
The console interface connection is through the back panel ETHERNET RJ45 ALERT2
network connector or SERIAL CONSOLE DB9 male serial connector. Both connections
require a login. The default login name is root with a password alert2. The login name
and password can be changed, see Section 4. Starting 2019, the default password was
changed to HydroLynx.
The console network connection is made using SSH on default port 22. This can be
changed, see Section 4.
The console serial connection is at 115,200 baud, no parity, 8 data bits, no stop bits, no
flow control. A NULL modem cable must be used for the serial connection.
3.5.2 ALERT2 Decoder Output

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 12 A102688
ALERT2 decoder output is through the back panel ETHERNET RJ45 network, SERIAL
DB9 female ALERT2, and SERIAL DB9 male CONSOLE serial connectors. ALERT2
Demodulator & Decoder ASCII and Binary Asynchronous Serial Interface format outputs
are provided on the network connection. Only the ALERT2 Demodulator & Decoder ASCII
Asynchronous Serial Interface format output is provided on the serial connections.
The ALERT2 decoder output serial connection is at 19200 baud, no parity, 8 data bits, no
stop bits, no flow control.
The ALERT2 decoder supports multiple server and client network connections. See
Section 4 for network client connection programming.
The ALERT2 decoder in server mode listens for TCP/IP network connections from up to
25 base station computers on port 4200 for ALERT2 Decoder ASCII format output and
port 4201 for ALERT2 Decoder Binary format output. There is no attempted reconnect for
connections lost in server mode.
The ALERT2 decoder in client mode will make TCP/IP network connections with remote
base station computer IP addresses and ports. The ALERT2 Receiver/Decoder will
attempt a reconnect every 30 seconds.
3.5.3 ALERT1 Decoder Output
ALERT1 decoder output is through the back panel ETHERNET RJ45 ALERT1 network
and SERIAL DB9 female ALERT1 serial connector when the Model 5052RD-OP1
ALERT1 Receiver/Decoder Option is installed. ALERT1 ASCII and Binary format outputs
are provided on the network connection and serial connection.
The ALERT1 decoder output serial connection is at 300 baud, no parity, 8 data bits, no
stop bits, no flow control.
The ALERT1 decoder supports multiple server or a single client connections. See Section
4 for network connection programming.
The ALERT1 decoder in server mode listens for TCP/IP network connections from
multiple base station computers on port 2101.
The ALERT1 decoder in client mode will make a single TCP/IP network connection with
remote base station computer IP address and port.
3.5.4 ALERT2 Transmit Input
ALERT2 encoder data input is through the back panel ETHERNET RJ45 ALERT2
network connector when the Model 5052RD-OP2 ALERT2 Transmit Option is installed.
The ALERT2 IND Encoder & Modulator Asynchronous Binary Serial Interface format is
supported.

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 13
4.0 Programming
4.1 ALERT2 Decoder Programming
The 5052RD-K ALERT2 Receiver/Decoder can be programmed using the console
interface. The console interface connection is through the back panel ETHERNET RJ45
ALERT2 network connector or SERIAL DB9 male CONSOLE serial connector. Use a
Windows terminal program such as HyperTerminal or PuTTY.
The console network connection is made using SSH on default port 22.
The serial connection is at 115,200 baud, no parity, 8 data bits, no stop bits, no flow
control. A NULL modem cable must be used for the serial connection.
Both network and serial connections require a login. The default login name is root with
a password alert2.
4.1.1 ALERT2 Decoder Enable Changes
In operational mode, the ALERT2 decoder file system is read-only. After logging in as
root, allow changes to be made by making the root file system read-write with the
command: mount / -o remount,rw
The file system can now be changed by adding, deleting, and editing files. The read-write
mode remains in effect until the ALERT2 decoder is rebooted or the file system is
remounted as read only.
Reboot with the ALERT2 decoder with the command: reboot
Restore the root file system read-only state with the command: mount / -o remount,ro
After rebooting you will have to reconnect and log in again.
4.1.2 ALERT2 Decoder Login Password Change
To change the login password, make the file system read-write then execute the
command: passwd
Enter new UNIX password: (Type your new password here, then press
[Enter])
Retype new UNIX password: (Repeat new password here, then press [Enter])
passwd: password updated successfully
4.1.3 ALERT2 Decoder IP Address Change
The ALERT2 Decoder IP address is set by DHCP by default, unless a factory IP setup
was requested. To determine the assigned IP address, launch a Windows Command
Prompt window and type the command: arp -a

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 14 A102688
Look for the IP address assigned to the ALERT2 decoder Physical Address which is on
the 5052RD-K ALERT2 Receiver/Decoder Test Results sheet on the ALERT2 decoder
line and serial number column. For example, the IP address 192.168.1.92 is assigned the
Physical Address 00-d0-69-4c-f7-db.
Display the ALERT2 decoder IP and Physical address on the console connection with the
command: ifconfig. In the eth0 section, the IP address follows inet addr: and the Physical
address follows HWaddr. For example:
ifconfig[Enter]
eth0 Link encap:Ethernet HWaddr 00:d0:69:4c:f7:db
inet addr:192.168.1.92 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::2d0:69ff:fe4c:f7db/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:359832 errors:2 dropped:0 overruns:0 frame:0
TX packets:71868 errors:2 dropped:0 overruns:0 carrier:2
collisions:0 txqueuelen:1000
RX bytes:26068643 (24.8 MiB) TX bytes:11430596 (10.9 MiB)
Interrupt:21 Base address:0x4000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 15
RX packets:16747 errors:0 dropped:0 overruns:0 frame:0
TX packets:16747 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:34142976 (32.5 MiB) TX bytes:34142976 (32.5 MiB)
To change ALERT2 decoder IP address, edit the file: /etc/network/interfaces.
Before editing the file, enable decoder changes by making the file system read-write:
Mount / -o remount,rw
Edit the network interface file with the command: vi /etc/network/interfaces
The file below has the IP address assigned by DHCP.
# Used by ifup(8) and ifdown(8). See the interfaces(5) manpage or
# /usr/share/doc/ifupdown/examples for more information.
# We always want the loopback interface.
#
auto lo
iface lo inet loopback
# auto eth0
# disable automatic eth0 up/down; it will be handled by
# ifplugd
iface eth0 inet dhcp
#iface eth0 inet static
# address 192.168.1.92
# netmask 255.255.255.0
# gateway 192.168.1.1
To disable DHCP and set a fixed IP address, put a #sign at the start of the line:
iface eth0 inet dhcp
Move to the start of the line, press the i key to start insert, type #at the start of the line,
then press [Esc] to quit the insert. The line should look like:
#iface eth0 inet dhcp
Move to the start of the line:
#iface eth0 inet static
Move the cursor under the #and press the xkey to delete the character.
iface eth0 inet static
Continue down the file removing the #character at the start of the following lines:
iface eth0 inet static
address 192.168.1.92
netmask 255.255.255.0
gateway 192.168.1.1
Change the fixed IP address for the ALERT2 decoder on the line:
address 192.168.1.92

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 16 A102688
Position the cursor over the IP address component to change, press xto delete a
character. Move the cursor after the space following the word address, then press ito
start insert mode, type the new IP address, then press [Esc] to quit the insert. Be careful
to leave two spaces at the start of the line.
Change the network mask on the line:
netmask 255.255.255.0
Change the network gateway IP address on the line:
gateway 192.168.1.1
Save your changes and quit, type the command: :wq (no [Enter] required)
To quit without saving use type the command: :q! (no [Enter] required)
Reboot the ALERT2 decoder to make the changes effective. Type the command: reboot
Restart your ALERT2 Decoder Console connection and log in again.
4.1.4 ALERT2 Decoder Network Time Sync
The ALERT2 Decoder requires a network time server synchronization to keep its time
current to the nearest second. ALERT2 data packets received from the radio are time
stamped with the current ALERT2 decoder time when deciding is finished. The base
station software uses the ALERT2 decoder receive time to compute the remote station
data report time from the data packet time stamp.
The default network time servers use the internet NTP server pool. If the 5052RD-K
ALERT2 Receiver/Decoder cannot connect to the internet, you must change to a private
time server. To change the time server, edit the file: /etc/ntp.conf.
Before editing the file, enable decoder changes by making the file system read-write:
mount / -o remount,rw
Edit the network interface file with the command: vi /etc/ntp.conf
The file below uses the internet NTP server pool.
server 127.127.28.0 minpoll 4
fudge 127.127.28.0 time1 0.200 refid GPS
server 127.127.28.1 minpoll 4 prefer
fudge 127.127.28.1 refid PPS
# Sanity checks
server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
server 3.pool.ntp.org iburst
# you should not need to modify the following paths
driftfile /var/lib/ntp/ntp.drift

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 17
# To deny other machines from changing the
# configuration but allow localhost:
restrict default nomodify nopeer
restrict 127.0.0.1
To disable the internet NTP server pool, put a # sign at the start of the lines:
server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
server 3.pool.ntp.org iburst
Move to the start of each line, press the i key to start insert, type #at the start of the line,
then press [Esc] to quit the insert. The lines should look like:
#server 0.pool.ntp.org iburst
#server 1.pool.ntp.org iburst
#server 2.pool.ntp.org iburst
#server 3.pool.ntp.org iburst
Move below these lines to a blank line and insert a new line for your private time server
IP address. Press the i key to start insert, type the following line using your timer server
IP address, press [Enter] at the end of the line, then press [Esc] to quit the insert.
server 192.168.1.24 prefer
In the example above the time server IP address is 192.168.1.24
Save your changes and quit, type the command: :wq (no [Enter] required)
To quit without saving use type the command: :q! (no [Enter] required)
Reboot the ALERT2 decoder to make the changes effective. Type the command: reboot
Restart your ALERT2 Decoder Console connection and log in again.
4.1.5 ALERT2 Decoder Network Client Connections
The ALERT2 Decoder supports up to 25 server connections from base station computers
on port 4200 for ASCII format, and port 4201 for Binary format.
Client connections can be added to the ALERT2 Decoder by editing the file:
/etc/default/alert2client.
Before editing the file, enable decoder changes by making the file system read-write:
mount / -o remount,rw
Edit the network interface file with the command: vi /etc/default/alert2client
# This file should contain a list of servers to forward data to,
# one per line. The format looks like:
# ascii|binary hostname:port
# ascii 192.168.1.40:4000 # ascii listener on 192.168.1.40, port 4000
# binary 192.168.1.40:4001 # binary listener on 192.168.1.40, port 4001

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 18 A102688
To add client connections, move the cursor to the bottom of the file on the last blank line,
press the i key to start insert, type format type (ascii or binary) a space, the IP address
followed by a color (:) then the connection port, [Enter] to finish the line, then press [Esc]
to quit the insert. For example to make an ASCII connection to a client at IP 192.168.1.24
and port 4000 add the line:
ascii 192.169.1.24:4000
Add one line per client connection.
Save your changes and quit, type the command: :wq (no [Enter] required)
To quit without saving use type the command: :q! (no [Enter] required)
Reboot the ALERT2 decoder to make the changes effective. Type the command: reboot
Restart your ALERT2 Decoder Console connection and log in again.
4.1.6 ALERT2 Decoder SSH port change
The console network connection is made using SSH on port 22 by default. This can be
changed to allow firewall routing. To change the ssh port, edit the file:
/etc/ssh/sshd_config.
Before editing the file, enable decoder changes by making the file system read-write:
mount / -o remount,rw
Edit the network interface file with the command: vi /etc/ssh/sshd_config
The file below has the ssh port set to the default port 22.
# Package generated configuration file
# See the sshd_config(5) manpage for details
# What ports, IPs and protocols we listen for
Port 22
# Use these options to restrict which interfaces/protocols sshd will
bind to
#ListenAddress ::
Position the cursor on the number 22 following the word Port on line 5, press xtwice to
delete the number 22. Move the cursor after the space following the word Port then press
ito start insert mode, type the new IP address, then press [Esc] to quit the insert.
Port 4203
Save your changes and quit, type the command: :wq (no [Enter] required)
To quit without saving use type the command: :q! (no [Enter] required)
Reboot the ALERT2 decoder to make the changes effective. Type the command: reboot
Restart your ALERT2 Decoder Console connection and log in again.
4.1.7 ALERT2 Decoder Host Name

Model 5052RD-K ALERT2 Receiver/Decoder HydroLynx Systems, Inc.
A102688 Page 19
The ALERT2 Decoder host name is defined as ts4200 by default. Change the host name
by adding the file: /etc/hostname containing the new host name.
For example, change the ALERT2 decoder name to a2decoder1. Display the current host
name with the command: hostname
hostname[Enter]
ts4200
Before creating the file, enable decoder changes by making the file system read-write:
mount / -o remount,rw[Enter]
Create the hostname file with the echo command:
echo “a2decoder1” >/etc/hostname[Enter]
Reboot the ALERT2 decoder to make the changes effective. Type the command: reboot
Restart your ALERT2 Decoder Console connection and log in again.
4.1.8 ALERT2 Decoder Name Servers and Host Names
The ALERT2 Decoder defines its name servers in the file: /etc/resolv.conf. Display the
current name servers with the command:
cat /etc/resolv.conf[Enter]
nameserver 8.8.8.8 # Google Public DNS
nameserver 4.2.2.1 # Level 3, Broomfield, CO
nameserver 4.2.2.2 # Level 3, Broomfield, CO
nameserver 151.197.0.38 # Verizon, Reston, VA
If your ALERT2 Decoder is on a private network, it cannot connect to the internet for the
name servers. Add your private name server by changing the file: /etc/resolv.conf
Before changing the file, enable decoder changes by making the file system read-write:
mount / -o remount,rw[Enter]
Create the hostname file with the echo command:
echo “nameserver My.Name.Server.IP” >/etc/resolv.conf[Enter]
You can remove the name servers and add your private network host names to the file:
/etc/hosts.
rm /etc/resolv.conf[Enter]
127.0.0.1 localhost

HydroLynx Systems, Inc. Model 5052RD-K ALERT2 Receiver/Decoder
Page 20 A102688
# IP6 definitions, do not change.
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters Edit the host file with the command: vi /etc/hosts
Move the cursor to the line below the last line printed, then press ito start insert mode,
type the host IP address, a space, the host name, then press [Enter] to finish the line.
Lines starting with #are comments. Continue adding IP addresses and host names until
done, then press [Esc] to quit the insert. For example:
# Local alert2 decoder name, change as needed.
192.168.1.92 a2decoder1
# NovaStar5 servers.
192.168.1.98 novastar5a
192.168.1.99 novastar5b
[Esc]
Save your changes and quit, type the command: :wq (no [Enter] required)
To quit without saving use type the command: :q! (no [Enter] required)
Reboot the ALERT2 decoder to make the changes effective. Type the command: reboot
Restart your ALERT2 Decoder Console connection and log in again.
4.2 ALERT1 Decoder Programming
4.2.1 ALERT1 Decoder IP Address Change
The ALERT1 Decoder IP address is set by DHCP by default, unless a factory IP setup
was requested. To determine the assigned IP address, launch a Windows Command
Prompt window and type the command: arp -a