RACOM RipEX 1.4 User manual

User manual
.
RipEX
Radio modem & Router
.
version 1.4
8/8/2012
fw 1.2.x.x
www.racom.eu
RACOMs.r.o. •Mirova1283•59231NoveMestonaMorave•CzechRepublic
Tel.:[phone]•Fax:[phone]•E-mail: [e-mail]

Table of Contents
Getting started ..................................................................................................................................... 7
1. RipEX – Radio router ...................................................................................................................... 9
1.1. Introduction ........................................................................................................................... 9
1.2. Key Features ........................................................................................................................ 9
1.3. Standards ........................................................................................................................... 10
2. RipEX in detail ............................................................................................................................... 12
2.1. Modes of operation ............................................................................................................. 12
2.2. Bridge mode ....................................................................................................................... 12
2.3. Router mode ....................................................................................................................... 17
2.4. Serial SCADA protocols ..................................................................................................... 22
2.5. Combination of IP and serial communication ..................................................................... 23
2.6. Diagnostics & network management .................................................................................. 23
2.7. Firmware update and upgrade ........................................................................................... 25
2.8. Software feature keys ......................................................................................................... 26
3. Network planning ........................................................................................................................... 27
3.1. Data throughput, response time ......................................................................................... 27
3.2. Frequency .......................................................................................................................... 28
3.3. Signal budget ..................................................................................................................... 29
3.4. Multipath propagation, DQ ................................................................................................. 31
3.5. Network layout .................................................................................................................... 33
3.6. Hybrid networks .................................................................................................................. 35
3.7. Assorted practical comments ............................................................................................. 35
3.8. Recommended values ........................................................................................................ 36
4. Product .......................................................................................................................................... 38
4.1. Dimensions ......................................................................................................................... 38
4.2. Connectors ......................................................................................................................... 39
4.3. Indication LEDs .................................................................................................................. 44
4.4. Technical specification ........................................................................................................ 45
4.5. Model offerings ................................................................................................................... 53
4.6. Accessories ........................................................................................................................ 55
5. Bench test ..................................................................................................................................... 60
5.1. Connecting the hardware ................................................................................................... 60
5.2. Powering up your RipEX .................................................................................................... 60
5.3. Connecting RipEX to a programming PC ........................................................................... 60
5.4. Basic setup ......................................................................................................................... 64
5.5. Functional test .................................................................................................................... 64
6. Installation ..................................................................................................................................... 65
6.1. Mounting ............................................................................................................................. 65
6.2. Antenna mounting .............................................................................................................. 68
6.3. Antenna feed line ............................................................................................................... 68
6.4. Grounding ........................................................................................................................... 69
6.5. Connectors ......................................................................................................................... 69
6.6. Power supply ...................................................................................................................... 69
7. Advanced Configuration ................................................................................................................ 70
7.1. Menu header ...................................................................................................................... 70
7.2. Status ................................................................................................................................. 71
7.3. Settings ............................................................................................................................... 72
7.4. Routing ............................................................................................................................. 104
7.5. Diagnostic ......................................................................................................................... 106
7.6. Maintenance ..................................................................................................................... 120
8. CLI Configuration ........................................................................................................................ 123
3© RACOM s.r.o. – RipEX Radio modem & Router

9. Troubleshooting ........................................................................................................................... 124
10. Safety, environment, licensing ................................................................................................... 126
10.1. Frequency ...................................................................................................................... 126
10.2. Safety distance ............................................................................................................... 126
10.3. High temperature ............................................................................................................ 130
10.4. RoHS and WEEE compliance ........................................................................................ 130
10.5. Conditions of Liability for Defects and Instructions for Safe Operation of Equipment .... 130
10.6. Important Notifications .................................................................................................... 131
10.7. Product Conformity ......................................................................................................... 132
A. OID mappings ............................................................................................................................. 133
B. Abbreviations .............................................................................................................................. 153
Index ................................................................................................................................................ 155
C. Revision History .......................................................................................................................... 157
List of Figures
1. RipEX radio router ........................................................................................................................... 7
2.1. Bridge mode example ................................................................................................................ 15
2.2. Addressing ................................................................................................................................. 20
2.3. Optimised addressing ................................................................................................................. 21
2.4. Monitoring ................................................................................................................................... 25
3.1. Application bench test ................................................................................................................ 28
3.2. Signal path ................................................................................................................................. 29
3.3. Multipath propagation ................................................................................................................. 31
3.4. Antenna location ......................................................................................................................... 32
3.5. Main lobe .................................................................................................................................... 33
3.6. Dominant repeater ...................................................................................................................... 34
3.7. Isolated branches ....................................................................................................................... 34
3.8. Antenna mounting ...................................................................................................................... 36
4.1. RipEX dimensions, see more ..................................................................................................... 38
4.2. L-bracket and Flat-bracket, see more ........................................................................................ 38
4.3. Connectors ................................................................................................................................. 39
4.4. Antenna connector TNC ............................................................................................................. 39
4.5. Separated Rx and TX antennas ................................................................................................. 40
4.6. Supply connector ........................................................................................................................ 41
4.7. Power and Control - cable plug .................................................................................................. 41
4.8. RJ-45F ........................................................................................................................................ 42
4.9. Serial connector ......................................................................................................................... 42
4.10. Serial connector ....................................................................................................................... 43
4.11. Reset ........................................................................................................................................ 43
4.12. GPS Connector SMA ............................................................................................................... 43
4.13. Indication LEDs ........................................................................................................................ 44
4.14. RipEX-HS ................................................................................................................................. 55
4.15. X5 adapter ETH/USB ............................................................................................................... 55
4.16. Demo case ............................................................................................................................... 56
4.17. Assembly dimensions with fan ................................................................................................. 57
4.18. L-bracket .................................................................................................................................. 57
4.19. Flat bracket ............................................................................................................................... 57
4.20. 19" Rack shelf .......................................................................................................................... 58
4.21. 19" Rack shelf – double ........................................................................................................... 58
4.22. Dummy load ............................................................................................................................. 58
5.1. Bench test .................................................................................................................................. 60
RipEX Radio modem & Router – © RACOM s.r.o.4
RipEX
Radio modem & Router

5.2. Connecting to a PC over ETH and over ETH/USB adapter ....................................................... 61
5.3. PC address setting ..................................................................................................................... 62
5.4. Authentication ............................................................................................................................. 63
5.5. Status Menu ............................................................................................................................... 63
6.1. Flat lengthwise mounting to DIN rail – recommended ............................................................... 65
6.2. Flat widthwise mounting to DIN rail ............................................................................................ 65
6.3. Vertical widthwise mounting to DIN rail ...................................................................................... 66
6.4. Vertical lengthwise mounting to DIN rail ..................................................................................... 66
6.5. Flat mounting using Flat bracket ................................................................................................ 66
6.6. Rack shelf ................................................................................................................................... 67
6.7. Fan kit mounting ......................................................................................................................... 67
6.8. Fan kit using Alarm Output, recommended ................................................................................ 68
6.9. Fan kit, always on ....................................................................................................................... 68
6.10. 10–30 VDC Supplying .............................................................................................................. 69
7.1. Menu Header .............................................................................................................................. 70
7.2. Menu Status ............................................................................................................................... 71
7.3. Menu Settings ............................................................................................................................ 72
7.4. Menu Alarm management .......................................................................................................... 78
7.5. Menu Radio ................................................................................................................................ 82
7.6. Menu Ethernet ............................................................................................................................ 85
7.7. Menu COM ................................................................................................................................. 90
7.8. Menu Protocols COM ................................................................................................................. 92
7.9. Menu Routing ........................................................................................................................... 104
7.10. Menu Neighbours ................................................................................................................... 106
7.11. Menu Statistic ......................................................................................................................... 109
7.12. Menu Graphs .......................................................................................................................... 110
7.13. Menu Ping .............................................................................................................................. 112
7.14. Menu Monitoring ..................................................................................................................... 115
7.15. Monitoring ............................................................................................................................... 119
7.16. Menu SW feature keys ........................................................................................................... 120
7.17. Menu Maintenance Configuration .......................................................................................... 121
7.18. Menu Maintenance Firmware ................................................................................................. 121
7.19. Menu Maintenance Password ................................................................................................ 122
7.20. Menu Maintenance Configuration .......................................................................................... 122
List of Tables
4.1. Pin assignement ......................................................................................................................... 40
4.2. Ethernet to cable connector connections ................................................................................... 42
4.3. COM1,2 pin description .............................................................................................................. 42
4.4. USB pin description .................................................................................................................... 43
4.5. Key to LEDs ............................................................................................................................... 44
4.6. Technical parameters ................................................................................................................. 45
4.7. Recommended Cables ............................................................................................................... 48
4.8. CE 25 kHz .................................................................................................................................. 49
4.9. CE 12.5 kHz ............................................................................................................................... 50
4.10. CE 6.25 kHz ............................................................................................................................. 50
4.11. FCC 25 kHz .............................................................................................................................. 51
4.12. FCC 12.5 kHz ........................................................................................................................... 51
4.13. FCC 6.25 kHz ........................................................................................................................... 51
10.1. Minimum Safety Distance 160 MHz ....................................................................................... 126
10.2. Minimum Safety Distance 300–400 MHz ............................................................................... 128
5© RACOM s.r.o. – RipEX Radio modem & Router
RipEX
Radio modem & Router

6

Getting started
RipEX is a widely configurable compact radio modem, more precisely a radio IP router. All you have
to do to put it into operation is to connect it to an antenna and a power supply and configure it using a
PC and a web browser.
Antenna Indicator LEDs' Sleep Input
HW Alarm Input
- GND
+
HW Alarm Output
Supply +10 to +30 V
- GND
Ethernet USB
COM1
RS232
COM2
RS232/485
Default/Reset
-
-++
SI AI
AO
10 – 30VDC
ETH USB
ANT
COM 1
COM 2
Fig. 1: RipEX radio router
RipEX access defaults: IP 192.168.169.169/24, username: admin, password: admin
Set a static IP 192.168.169.x/24 on your PC, power on the RipEX and wait approximately 25 seconds
for the RipEX OS to boot. Connect your PC to RipEXs' ETH interface, start your browser and type ht-
tps://192.168.169.169 in the address line. When accessing RipEX for the first time, you have to accept
the https security certificate issued by Racom.
Before attempting to do any configuration, make sure your RipEX is the only powered-up unit around.
Since all units coming from factory share the same default settings ex factory, you could be accessing
a different unit over the air without being aware of it.
When accessing over the optional “X5” USB/ETH adapter, your PC will get its IP settings from the built-
in DHCP server and you have to type https://10.9.8.7 in your browser. Remaining steps are the same
and you do not need to worry about other RipEX's, you will be connected to the local unit in all cases.
SCADA radio network step-by-step
Building a reliable radio network for a SCADA system may not be that simple, even when you use such
a versatile and easy-to-operate device as the RipEX radio modem. The following step-by-step checklist
can help you to keep this process fast and efficient.
1. Design your network to ensure RF signal levels meet system requirements.
2. Calculate and estimate the network throughput and response times when loaded by your application.
3. Perform a bench-test with 3-5 sets of RipEX's and SCADA equipment (Chapter 5, Bench test).
4. Design the addressing and routing scheme of the network (Chapter 2, RipEX in detail and RipEX
App notes, Address planing1)
5. Preconfigure all RipEX's (Section 5.4, “Basic setup”).
6. Install individual sites
1. Mount RipEX into cabinet (Section 6.1, “Mounting”).
1http://www.racom.eu/eng/products/m/ripex/app/routing.html
7© RACOM s.r.o. – RipEX Radio modem & Router
Getting started

2. Install antenna (Section 6.2, “Antenna mounting”).
3. Install feed line (Section 6.3, “Antenna feed line”).
4. Ensure proper grounding (Section 6.4, “Grounding”).
5. Run cables and plug-in all connectors except from the SCADA equipment (Section 4.2,
“Connectors”)
6. Apply power supply to RipEX
7. Test radio link quality (Section 5.5, “Functional test”).
8. Check routing by the ping tool (the section called “Ping”) to verify accessibility of all IP ad-
dresses with which the unit will communicate.
9. Connect the SCADA equipment
7. Test your application
RipEX Radio modem & Router – © RACOM s.r.o.8
Getting started

1. RipEX – Radio router
1.1. Introduction
RipEX is a best-in-class radio modem, not only in terms of data transfer speed. This Software Defined
Radio with Linux OS has been designed with attention to detail, performance and quality. All relevant
state-of-the-art concepts have been carefully implemented.
RipEX provides 24×7 reliable service for mission-critical applications like SCADA & Telemetry for Util-
ities, SmartGrid power networks or transaction networks connecting lottery terminals, POS or ATM’s.
Any unit can serve as the central master, repeater, remote terminal, or all of these simultaneously, with
a configuration interface easily accessible from a web browser.
Anybody with even basic knowledge of IP networking can set up a RipEX within a matter of minutes
and maintain the network quite easily.
1.2. Key Features
• Exceptional data speeds on the radio channel
- 83 kbps / 25 kHz, 42 kbps / 12.5 kHz, 21 kbps / 6.25 kHz
• 1× ETH, 2× COM, 1× USB, 5× virtual COM
- Simultaneously on radio channel. COM1-RS232, COM2-RS232 or RS485, software configurable.
Virtual COMs over ETH controlled by Terminal servers. USB for independent service access via
USB/ETH adapter.
• 135–175; 300–360; 368–470; 928–960 MHz
- Licensed radio bands
- Software-selectable channel spacing 25, 12.5 or 6.25 kHz
• 10 watts
- Transmission output control, nine stages from 0.1 to 10 W (max. 2 W for linear modulations).
• Energy saving
- Sleep mode – 0.1 W, controlled via a digital input.
- Save mode – 2.3 W, wake up by receiving a packet from the radio channel
• Extended temperature range
−40 to +70 ºC
• Easy to configure and maintain
- Web interface,
- Wizards,
- On-line help,
- Balloon tips,
- Fastest web access to remote units
• Bridge or Router
- RipEX is a device with native IP support which can be set as a standard bridge or router.
9© RACOM s.r.o. – RipEX Radio modem & Router
RipEX – Radio router

• Modbus, IEC101, DNP3, Comli, RP570, C24, DF1, Profibus, Modbus TCP, IEC104, DNP3 TCP
etc.
- Unique implementation of industrial protocols enables a secure addressed transmission of all
packets in all directions
• Anti-collision protocol on radio channel
- Allows multi polling & report-by-exception concurrently for several independent applications sim-
ultaneously
• Optimization – 3× higher throughput
- Optimization method which joins short packets, compresses data, optimises both the traffic to the
link peer and the sharing of the radio channel capacity among the links.
• Embedded diagnostic & NMS
- Real time and historical (20 periods, e.g. days) statistics and graphs for the unit and its neighbours.
- SNMP including generation of TRAP alarms when preset thresholds are exceeded
- on-line/off-line (recorded to a file in the RipEX) monitoring of all interfaces
• 256 AES encryption
- The most secure encryption meets FIPS 140 2 requirements
• Pay only for what you need
- Software authorization keys allow you to add advanced features when needed (Router mode, 83
kbps, COM2, 10 W)
- Free Master-key trial – (all coded features) for 30 days in every RipEX
• Reliability
- 3 years warranty, rugged die cast aluminium case, military or industrial components
- Every single unit tested in a climatic chamber as well as in real traffic
• RipEX - HS
- Redundant hot standby chassis
- Two hot-stand-by standard RipEX units inside
- Automatic switchover capability on detection of failure
- Suitable for Central sites, Repeaters or Important remote sites where no single point of failure is
required
• Internal calendar time
- Can be set manually or synchronized via NTP (Network Time Protocol)
- Any RipEX also runs as a NTP server automatically
- NTP synchronization via Ethernet or over the Radio channel from another RipEX
- Powered from internal long life Lithium Manganese battery, so it is accurate even when RipEX is
powered off
• Flash memory
- All configuration parameters are saved in flash memory
- Configuration and other parameters are safely saved even when RipEX is powered off
1.3. Standards
ETSI EN 300 113-2 V1.5.1Spectrum (art 3.2)
FCC Part 90
ETSI EN 301 489-1 V1.9.2EMC (art 3.1.b)
RipEX Radio modem & Router – © RACOM s.r.o.10
RipEX – Radio router

ETSI EN 301 489-5 V1.3.1
EN 60950-1:2006Electrical Safety (art 3.1.a)
EN 60950–1:2006/A11:2009,
EN 60950–1:2006/A12:2011,
EN 60950–1:2006/A1:2010
IP40IP rating
IEEE 802.3iETH
IEEE 802.3u
IEEE 802.3af
EIA-232-FRS232
EIA RS-485RS485
IEC 60870-5-101IEC101
IEC 60870-5-104IEC104
IEEE 1815-2010DNP3
IEC 61158 Type 3Profibus DP
11© RACOM s.r.o. – RipEX Radio modem & Router
RipEX – Radio router

2. RipEX in detail
2.1. Modes of operation
Radio modem RipEX is best suited for transmission of a large number of short messages where a
guaranteed delivery time is required, i.e. for mission critical applications.
RipEX has the following basic uses:
• Polling
In poll-response networks a central master unit communicates with a number of remote radiomodems
one at a time. The master unit exchanges data with the currently connected remote radio, and when
finished, it establishes a new connection with the next remote radio according to the polling order.
• Report-by-exception
In report-by-exception networks remote units can be contacted similarly to polling networks. In ad-
dition, any remote unit can spontaneously send data to the master unit (typically an alarm).
• Mesh
In mesh type networks any radio modem in the network can access any other radio modem randomly
and spontaneously. Mesh network can also host polling or report-by-exception applications, even
in several instances.
2.2. Bridge mode
A packet received through any interface is broadcast to the appropriate interfaces of all units within the
network. Packets received on COM are broadcast to both COM1 and COM2 at remote sites, allowing
you to connect 2 RTU's to any radio modem.
Any unit can be configured as a repeater. A repeater relays all packets it receives through the radio
channel. The network implements safety mechanisms which prevent cyclic loops in the radio channel
(e.g. when a repeater receives a packet from another repeater) or duplicate packets delivered to the
user interface (e.g. when RipEX receives a packet directly and then from a repeater).
Beside standard packet termination by an "Idle" period on the serial port (a pause between received
bytes) the bridge mode also offers "streaming". While in streaming mode, transmission on the radio
channel starts immediately, without waiting for the end of the received frame on COM => zero latency.
The bridge mode is suitable for all polling applications.
2.2.1. Detailed Description
Bridge mode is suitable for Point-to-Multipoint networks, where Master-Slave applications with polling-
type communication protocol are used. RipEX in bridge mode is as easy to use as a simple transparent
device, while providing communication reliability and spectrum efficiency by employing a sophisticated
protocol in the radio channel.
In bridge mode, the radio channel protocol do not solve collisions. There is a CRC check of data integrity,
however, i.e. once a message is delivered, it is 100% error free.
RipEX Radio modem & Router – © RACOM s.r.o.12
RipEX in detail

All the messages received from user interfaces (ETH&COM's) are immediately transmitted to the radio
channel.
ETH - The whole network of RipEX radiomodems behaves as a standard ethernet network bridge.
Each ETH interface automatically learns which devices (MAC addresses) are located in the local LAN
and which devices are accessible over the radio channel. Consequently, only the ethernet frames ad-
dressed to remote devices are physically transmitted on the radio channel. This arrangement saves
the precious RF spectrum from extra load which would be otherwise generated by local traffic in the
LAN (the LAN to which the respective ETH interface is connected).
COM1,COM2 - All frames received from COM1(2) are broadcast over the radio channel and transmitted
to all COM's (COM1 as well as COM2) on all radio modems within the network, the other COM on the
source RipEX excluding.
There is a special parameter TX delay (Adv. Config., Device), which should be used when all substations
(RTU's) reply to a broadcast query from the master station. In such case massive collisions would ensue
because all substations (RTU's) would reply at nearly the same time. To prevent such collision, TX
delay should be set individually in each slave RipEX. The length of responding frame, the length of
radio protocol overhead, modulation rate have to be taken into account.
2.2.2. Functionality example
In the following, common acronyms from SCADA systems are used:
• FEP - Front End Processor, designates the communication interface equipment in the centre
• RTU - Remote Telemetry Unit, the terminal SCADA equipment at remote sites
The single digits in illustrations are “site names” and do not necessarily correspond with actual addresses
of both the RipEX's and SCADA equipment. Address configuration examples are given in the next
chapter.
Step 1
Polling cycle starts:
FEP sends a request packet for RTU3 through COM1 to
the connected RipEX.
Step 2
FEP’s RipEX broadcasts this packet on Radio channel.
RipEX3 and RipEX1 receive this packet.
RipEX2 doesn’t receive this packet, because it is not within
radio coverage of FEP’s RipEX.
13© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

Step 3
RipEX3 and RipEX1 send the received packet to their
COM1 and COM2.
Packet is addressed to RTU3, so only RTU3 responds.
RipEX1 is set as a repeater, so it retransmits the packet
on Radio channel. Packet is received by all RipEXes.
Step 4
RipEX2 sends repeated packet to its COM1 and COM2.
RTU2 doesn’t react, because the packet is addressed to
RTU3.
RipEX3 and FEP’s RipEX do not send the repeated
packet to their COM ports, because it has already been
sent (RipEX3) or received (FEP’s RipEX) on their COM
(anti-duplication mechanism).
RTU3 sends the reply packet.
Step 5
RipEX3 broadcasts the reply packet from RTU3 on Radio
channel.
Packet is received by RipEX1 and FEP’s RipEX.
Step 6
FEP’s RipEX sends the packet (the reply from RTU3) to
FEP through COM1.
RipEX1 sends this packet to RTU1. RTU1 doesn’t react,
because the packet is addressed to FEP.
RipEX1 repeats the packet on Radio channel.
All RipEXes receive the packet.
Step 7
RipEX2 sends repeated packet to its COM1 and COM2.
RTU2 doesn’t react, because the packet is addressed to
FEP.
RipEX3 and FEP’s RipEXes do not send the repeated
packet to their COM ports, because it has been handled
already.
FEP processes the reply from RTU3 and polling cycle
continues…
RipEX Radio modem & Router – © RACOM s.r.o.14
RipEX in detail

2.2.3. Configuration examples
You can see an example of IP addresses of the SCADA equipment and RipEX's ETH interfaces in the
picture below.
In Bridge mode, the IP address of the ETH interface of RipEX is not relevant for user data communic-
ation. However it is strongly recommended to assign a unique IP address to each RipEXs' ETH interface,
since it allows for easy local as well as remote service access. Moreover, leaving all RipEX's with the
same (= default) IP on the ETH interface may cause serious problems, when more RipEX's are con-
nected to the samX5e LAN, even if by accident (e.g. during maintenance).
192.168.5.51/24
192.168.5.50/24
192.168.5.12/24
192.168.5.2/24
192.168.5.3/24
192.168.5.11/24
192.168.5.1/24
192.168.5.13/24 3
FEP
50
1
2
REPEATER
Fig. 2.1: Bridge mode example
Repeater
Because using the bridge mode makes the network transparent, the use of repeaters has certain limit-
ations. To keep matters simple we recommend using a single repeater. However, if certain rules are
observed, using multiple repeaters in the same network is possible.
The total number of repeaters in the network is configured for every unit individually under Bridge mode
parameters. This information is contained in every packet sent. All units that receive such packet will
resume transmission only after sufficient time has been allowed for the packet to be repeated. The
packets received from user ports remain buffered and are sent after the appropriate time passes. This
prevents collisions between remote radio modems. There can be no repeater collisions if only one re-
peater is used.
15© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

Where two or more repeaters are used, collisions resulting from simultaneous reception of a repeated
packet must be eliminated. Collisions happen because repeaters repeat packets immediately after re-
ception, i.e. if two repeaters receive a packet from the centre, they both relay it at the same time. If
there is a radiomodem which is within the range of both repeaters, it receives both repeated packets
at the same time rendering them unreadable.
Examples:
1. Repeaters connected serially
A packet is transmitted and repeated
in steps 1, 2, 3.
Centre RPT1 RPT2 Remote
1 2 3
In improperly designed networks collisions happen
if a remote radio modem lies in the range of two
X
COLLISION!
1
12
2
WRONG
CEN RPT1 RPT2 REM
repeaters (see the image): the packet sent from
the centre (1) is received by both repeaters. It is
repeated by them both (2) causing a collision at
the remote. In other words – there should not be
more than one repeater where the centre and re-
motes' coverage areas overlap.
Solution 1.
Adjust signal coverage so that RPT2 is out of range
of the centre and RPT1 is out of the range of the
GOOD
Coverage area
123
CEN RPT1 RPT2 REM
remote radio modem. This can be achieved for
example by reducing the output power or using a
unidirectional antenna.
Solution 2.
Use a single repeater. (Whenever network layout
allows that.)
12
Good
CEN RPT1 REM
RipEX Radio modem & Router – © RACOM s.r.o.16
RipEX in detail

2. Parallel repeaters
Improperly designed network:
Centre
Repeater1
Remote1
1
2
1
2
Remote2
Repeater2
X
COLLISION!
GOOD
WRONG
1
2
1
2
CEN
CEN
RPT1
RPT1
REM1
REM1
1
2
1
2
REM2
REM2
RPT2
RPT2
2
- RipEX REM1 is within the range
of two repeaters (RPT1 and RPT2).
The repeaters receive a packet (1)
from the centre (CEN) and repeat
it at the same time (2) causing a
collision at REM1.
Well-designed network:
- A remote is only in the range of a
single repeater (REM1-RPT1,
REM2-RPT2).
There is always only one repeater
where the centre and remote cov-
erage areas overlap.
2.3. Router mode
RipEX works as a standard IP router with two interfaces (radio and ethernet) and two COM port devices.
There is a sophisticated anti-collision protocol on the radio channel, which checks and verifies every
single packet. Being an IP router, each unit can simultaneously work as a store-and-forward repeater
and deliver packets to the connected equipment.
The router mode is suitable for all uses. In contrast to the bridge mode, a packet reception is confirmed
over the radio channel even in very simple polling type applications, and if necessary the packet is re-
transmitted.
2.3.1. Detailed Description
Router mode is suitable for multipoint networks, where multi-master applications with any combination
of polling and/or spontaneous data protocols can be used. The proprietary link-layer protocol on the
radio channel is very sophisticated, it can transmit both unicast and broadcast frames, it has collision
avoidance capability, it uses frame acknowledgement, retransmissions and CRC checks to guarantee
data delivery and integrity even under harsh interference conditions on the radio channel.
RipEX works as a standard IP router with 2 independent interfaces: radio and ETH. Each interface has
its own MAC address, IP address and mask.
IP packets are processed according the routing table rules. You can also set the router’s default gateway
(applies to both interfaces) in the routing table.
The COM ports are treated as standard host devices, messages can be delivered to them as UDP
datagrams to selected port numbers. The destination IP address of a COM port is either the IP of ETH
or the IP of a radio interface. The source IP address of outgoing packets from COM ports is always the
IP of the ETH interface.
17© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

2.3.2. Functionality example
In the following example, there are two independent SCADA devices connected to RipEX's two COM
ports. One is designated RTU (Remote Telemetry Unit) and is assumed to be polled from the centre
by the FEP (Front End Processor). The other is labelled PLC (Programmable Logic Controller) and is
assumed to communicate spontaneously with arbitrary chosen peer PLCs.
Step 1
FEP sends a request packet for RTU1 through COM2 to
its connected RipEX.
Simultaneously PLC2 sends a packet for PLC1 to RipEX2
through COM1.
Step 2
FEP’s RipEX transmits an addressed packet for RTU1 on
Radio channel.
RipEX1 receives this packet, checks data integrity and
transmits the acknowledgement.
At the same time packet is sent to RTU1 through COM2.
RipEX3 receives this packet too. It doesn’t react, because
this packet is directed to RipEX1 only.
Step 3
RipEX2 waits till previous transaction on Radio channel is
finished (anti-collision mechanism).
Then RipEX2 transmits on Radio channel the addressed
packet for PLC1.
RipEX1 receives this packet, checks data integrity and
transmits acknowledgement.
At the same time packet is sent to PLC1 through COM1.
Simultaneously the reply packet from RTU1 for FEP is re-
ceived on COM2.
Step 4
RipEX1 transmitts the reply packet from RTU1 for FEP on
Radio channel.
All RipEXes receive this packet. This packet is addressed
to FEP’s RipEX, so only FEP’s RipEX reacts. It checks
data integrity and transmits the acknowledgement to
RipEX1.
At the same time the packet is sent to FEP through COM2.
RipEX Radio modem & Router – © RACOM s.r.o.18
RipEX in detail

Step 5
FEP receives the response from RTU1 and polling cycle
continues…
However any PLC or RTU can spontaneously send a
packet to any destination anytime.
2.3.3. Configuration examples
As it was mentioned above, RipEX radiomodem works as a standard IP router with two independent
interfaces: radio and ETH. Each interface has got its own MAC address, IP address and mask.
The IP router operating principles stipulate that every unit can serve as a repeater.. Everything what
is needed is the proper configuration of routing tables.
Radio IP addresses of the RipEX’s required to communicate over the radio channel must share the
same IP network. We recommend planning your IP network so that every RipEX is connected to a
separate sub-network over the ethernet port. This helps to keep the routing tables clear and simple.
Note
Even if the IP addresses of all RipEXes in a radio channel share a single IP network, they
may not be communicating directly as in a common IP network. Only the RipEXes that are
within the radio range of each other can communicate directly. When communication with
radio IP addresses is required, routing tables must include even the routes that are within
the same network (over repeaters), which is different from common IP networks. The example
configuration below does not show such routing rules for the sake of simplicity (they are not
needed in most cases).
19© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

10.10.10.50/24
192.168.50.2/24
Routing table RipEX50:
192.168.1.0/24 10.10.10.1
192.168.2.0/24 10.10.10.1
192.168.3.0/24 10.10.10.3
Default GW 192.168.50.2
è
è
è
192.168.2.2/24
Routing table :
192.168.1.0/24 10.10.10.1
RipEX2
192.168.50.0/24 10.10.10.1
192.168.3.0/24 10.10.10.1
è
è
è
10.10.10.3/24
192.168.3.2/24
Routing table RipEX3:
192.168.50.0/24 10.10.10.50
192.168.1.0/24 10.10.10.50
192.168.2.0/24 10.10.10.50
è
è
è
10.10.10.1/24
192.168.1.1/24
192.168.1.2/24
Routing table :
192.168.2.0/24 10.10.10.2
RipEX1
192.168.50.0/24 10.10.10.50
192.168.3.0/24 10.10.10.50
è
è
è
192.168.3.1/24 3
50
FEP
1
192.168.50.1/24
Radio IP
ETH IP
FEP IP
10.10.10.2/24
2
192.168.2.1/24
Fig. 2.2: Addressing
Formal consistency between the last byte of the radio IP address and the penultimate byte of the eth-
ernet address is not necessary but simplifies orientation. The “Addressing” image shows a routing table
next to every RipEX. The routing table defines the next gateway for each IP destination. In radio
transmission, the radio IP of the next radio-connected RipEX serves as the gateway.
Example of a route from FEP (RipEX 50) to RTU 2:
• The destination address is 192.168.2.2
• The routing table of the RipEX 50 contains this record:
Destination 192.168.2.0/24 Gateway 10.10.10.1
• Based on this record, all packets with addresses in the range from 192.168.2.1 to 192.168.2.254
are routed to 10.10.10.1
• Because RipEX 50’s radio IP is 10.10.10.50/24, the router can tell that the IP 10.10.10.1 belongs
to the radio channel and sends the packet to that address over the radio channel
• The packet is received by RipEX 1 with the address 10.10.10.1 where it enters the router
• The routing table of RipEX 1 contains the record:
Destination 192.168.2.0/24 Gateway 10.10.10.2
based on which the packet is routed to 10.10.10.2 over the radio channel
• The packet is received by RipEX 2
• The router compares the destination IP 192.168.2.2 with its own ethernet address 192.168.2.1/24
and determines that the packet’s destination is within its ETH network and sends the packet over
the ethernet interface – eventually, the packet is received by RTU 2.
RipEX Radio modem & Router – © RACOM s.r.o.20
RipEX in detail