RACOM RipEX User manual

User manual
.
RipEX
Radio modem & Router
.
version 1.20
08/16/2017
fw 1.7.x.x
www.racom.eu
RACOMs.r.o. •Mirova1283•59231NoveMestonaMorave•CzechRepublic
Tel.:[phone]•Fax:[phone]•E-mail: [e-mail]

Table of Contents
Important Notice .................................................................................................................................. 7
Quick guide ......................................................................................................................................... 8
1. RipEX – Radio router .................................................................................................................... 10
1.1. Introduction ......................................................................................................................... 10
1.2. Key Features ...................................................................................................................... 10
2. RipEX in detail ............................................................................................................................... 13
2.1. Applications ........................................................................................................................ 13
2.2. Bridge mode ....................................................................................................................... 13
2.2.1. Detailed Description ................................................................................................ 14
2.2.2. Functionality example .............................................................................................. 14
2.2.3. Configuration examples ........................................................................................... 16
2.3. Router mode ....................................................................................................................... 19
2.3.1. Router - Flexible, Detail description ......................................................................... 20
2.3.2. Router - Flexible, Functionality example ................................................................. 20
2.3.3. Router - Flexible, Configuration examples .............................................................. 21
2.3.4. Router - Flexible, Addressing hints .......................................................................... 23
2.3.5. Router - Base driven, Detail description .................................................................. 24
2.3.6. Router - Base driven, Functionality example ........................................................... 24
2.3.7. Router - Base driven, Configuration example ......................................................... 25
2.4. Serial SCADA protocols ..................................................................................................... 27
2.4.1. Detailed Description ................................................................................................ 27
2.5. Combination of IP and serial communication ..................................................................... 28
2.5.1. Detailed Description ................................................................................................ 28
2.6. Diagnostics & network management .................................................................................. 29
2.6.1. Logs ......................................................................................................................... 29
2.6.2. Graphs ..................................................................................................................... 29
2.6.3. SNMP ...................................................................................................................... 29
2.6.4. Ping ......................................................................................................................... 30
2.6.5. Monitoring ................................................................................................................ 30
2.7. Firmware update and upgrade ........................................................................................... 30
2.8. Software feature keys ......................................................................................................... 31
3. Network planning ........................................................................................................................... 32
3.1. Data throughput, response time ......................................................................................... 32
3.2. Frequency .......................................................................................................................... 33
3.3. Signal budget ..................................................................................................................... 34
3.3.1. Path loss and fade margin ....................................................................................... 35
3.4. Multipath propagation, DQ ................................................................................................. 35
3.4.1. How to battle with multipath propagation? .............................................................. 36
3.5. Network layout .................................................................................................................... 38
3.6. Hybrid networks .................................................................................................................. 40
3.7. Assorted practical comments ............................................................................................. 40
3.8. Recommended values ........................................................................................................ 41
4. Product .......................................................................................................................................... 43
4.1. Dimensions ......................................................................................................................... 43
4.2. Connectors ......................................................................................................................... 46
4.2.1. Antenna ................................................................................................................... 46
4.2.2. Power and Control ................................................................................................... 47
4.2.3. ETH ......................................................................................................................... 49
4.2.4. COM1 and COM2 .................................................................................................... 49
4.2.5. USB ......................................................................................................................... 50
4.2.6. Reset button ............................................................................................................ 52
3© RACOM s.r.o. – RipEX Radio modem & Router

4.2.7. GPS ......................................................................................................................... 53
4.3. Indication LEDs .................................................................................................................. 54
4.4. Technical specification ........................................................................................................ 55
4.4.1. Detailed Radio parameters ...................................................................................... 59
4.5. Model offerings ................................................................................................................... 69
4.5.1. Ordering code (Part No’s) ........................................................................................ 69
4.6. Accessories ........................................................................................................................ 72
5. Bench test ..................................................................................................................................... 80
5.1. Connecting the hardware ................................................................................................... 80
5.2. Powering up your RipEX .................................................................................................... 80
5.3. Connecting RipEX to a programming PC ........................................................................... 80
5.4. Basic setup ......................................................................................................................... 84
5.5. Functional test .................................................................................................................... 84
6. Installation ..................................................................................................................................... 85
6.1. Mounting ............................................................................................................................. 85
6.1.1. DIN rail mounting ..................................................................................................... 85
6.1.2. Flat mounting ........................................................................................................... 87
6.1.3. 19" rack mounting .................................................................................................... 88
6.1.4. IP51 mounting ......................................................................................................... 88
6.2. Antenna mounting .............................................................................................................. 88
6.3. Antenna feed line ............................................................................................................... 89
6.4. Grounding ........................................................................................................................... 89
6.5. Connectors ......................................................................................................................... 89
6.6. Power supply ...................................................................................................................... 90
7. Advanced Configuration ................................................................................................................ 91
7.1. Menu header ...................................................................................................................... 91
7.2. Status ................................................................................................................................. 93
7.2.1. Device, Radio, ETH&COM ...................................................................................... 93
7.2.2. Diagnostic ................................................................................................................ 93
7.3. Settings ............................................................................................................................... 94
7.3.1. Device ...................................................................................................................... 94
7.3.2. Radio ..................................................................................................................... 116
7.3.3. ETH ....................................................................................................................... 134
7.3.4. COM ...................................................................................................................... 143
7.3.5. Protocols ................................................................................................................ 145
7.4. Routing ............................................................................................................................. 161
7.4.1. Interfaces ............................................................................................................... 161
7.4.2. Routes ................................................................................................................... 162
7.4.3. Backup ................................................................................................................... 162
7.5. VPN .................................................................................................................................. 165
7.5.1. IPsec ...................................................................................................................... 165
7.5.2. GRE ....................................................................................................................... 173
7.6. Diagnostic ......................................................................................................................... 176
7.6.1. Neighbours and Statistic ........................................................................................ 176
7.6.2. Graphs ................................................................................................................... 180
7.6.3. Ping ....................................................................................................................... 182
7.6.4. Monitoring .............................................................................................................. 187
7.7. Maintenance ..................................................................................................................... 199
7.7.1. SW feature keys .................................................................................................... 199
7.7.2. Configuration ......................................................................................................... 200
7.7.3. Firmware ................................................................................................................ 200
7.7.4. Administrator account ............................................................................................ 202
RipEX Radio modem & Router – © RACOM s.r.o.4
RipEX
Radio modem & Router

7.7.5. Miscellaneous ........................................................................................................ 202
7.7.6. SSL certificate ....................................................................................................... 202
7.7.7. Remote access keys ............................................................................................. 203
7.7.8. RF transmission test .............................................................................................. 204
7.7.9. Technical support package .................................................................................... 204
8. CLI Configuration ........................................................................................................................ 205
8.1. CLI Examples ................................................................................................................... 205
9. Troubleshooting ........................................................................................................................... 208
10. Safety, environment, licensing ................................................................................................... 210
10.1. Frequency ...................................................................................................................... 210
10.2. Safety distance ............................................................................................................... 210
10.3. High temperature ............................................................................................................ 214
10.4. RoHS and WEEE compliance ........................................................................................ 214
10.5. Hazardous locations ....................................................................................................... 215
10.6. Conditions of Liability for Defects and Instructions for Safe Operation of Equipment .... 216
10.7. Important Notifications .................................................................................................... 216
10.8. EU Declaration of Conformity ......................................................................................... 218
10.9. Simplified EU declaration of conformity .......................................................................... 219
10.10. ATEX Certificate ........................................................................................................... 221
10.11. Compliance Federal Communications Commission ..................................................... 224
10.12. Country of Origin .......................................................................................................... 225
10.13. Warranty ....................................................................................................................... 226
10.14. RipEX maintenance ...................................................................................................... 227
A. OID mappings ............................................................................................................................. 228
B. Abbreviations .............................................................................................................................. 229
Index ................................................................................................................................................ 231
C. Revision History .......................................................................................................................... 233
List of Tables
4.1. Pin assignment ........................................................................................................................... 47
4.2. Ethernet to cable connector connections ................................................................................... 49
4.3. COM1, 2 pin description ............................................................................................................. 50
4.4. USB pin description .................................................................................................................... 50
4.5. Key to LEDs ............................................................................................................................... 54
4.6. Technical parameters ................................................................................................................. 55
4.7. Recommended Cables ............................................................................................................... 58
4.8. Unlimited 50 kHz ........................................................................................................................ 59
4.9. CE 50 kHz .................................................................................................................................. 60
4.10. CE 25 kHz ................................................................................................................................ 61
4.11. CE 12.5 kHz ............................................................................................................................. 62
4.12. CE 6.25 kHz ............................................................................................................................. 63
4.13. FCC 50 kHz .............................................................................................................................. 64
4.14. FCC 25 kHz .............................................................................................................................. 64
4.15. FCC 25 kHz RipEX-928, RipEX-215 ........................................................................................ 65
4.16. FCC 12.5 kHz ........................................................................................................................... 66
4.17. FCC 6.25 kHz ........................................................................................................................... 66
4.18. Narrow 25 kHz .......................................................................................................................... 67
10.1. Minimum Safety Distance 160 MHz ....................................................................................... 210
10.2. Minimum Safety Distance 216–220 MHz ............................................................................... 212
10.3. Minimum Safety Distance 300–400 MHz ............................................................................... 212
10.4. Minimum Safety Distance 928–960 MHz ............................................................................... 214
5© RACOM s.r.o. – RipEX Radio modem & Router
RipEX
Radio modem & Router

10.5. Maximum voltage and current of individual interfaces ........................................................... 216
10.6. Compliance Federal Communications Commission .............................................................. 224
RipEX Radio modem & Router – © RACOM s.r.o.6
RipEX
Radio modem & Router

Important Notice
Copyright
© 2017 RACOM. All rights reserved. COM’s
Products offered may contain software proprietary to RACOM s. r. o. (further referred to under the ab-
breviated name RACOM). The offer of supply of these products and services does not include or infer
any transfer of ownership. No part of the documentation or information supplied may be divulged to
any third party without the express written consent of RACOM.
Disclaimer
Although every precaution has been taken in preparing this information, RACOM assumes no liability
for errors and omissions, or any damages resulting from the use of this information. This document or
the equipment may be modified without notice, in the interests of improving the product.
Trademark
All trademarks and product names are the property of their respective owners.
Important Notice
• Due to the nature of wireless communications, transmission and reception of data can never be
guaranteed. Data may be delayed, corrupted (i.e., have errors), or be totally lost. Significant delays
or losses of data are rare when wireless devices such as the RipEX are used in an appropriate
manner within a well‐constructed network. RipEX should not be used in situations where failure to
transmit or receive data could result in damage of any kind to the user or any other party, including
but not limited to personal injury, death, or loss of property. RACOM accepts no liability for damages
of any kind resulting from delays or errors in data transmitted or received using RipEX, or for the
failure of RipEX to transmit or receive such data.
• Under no circumstances is RACOM or any other company or person responsible for incidental,
accidental or related damage arising as a result of the use of this product. RACOM does not provide
the user with any form of guarantee containing assurance of the suitability and applicability for its
application.
• RACOM products are not developed, designed or tested for use in applications which may directly
affect health and/or life functions of humans or animals, nor to be a component of similarly important
systems, and RACOM does not provide any guarantee when company products are used in such
applications.
•The equipment should be used in hazardous locations under conditions according to Section 10.5,
“Hazardous locations” only.
7© RACOM s.r.o. – RipEX Radio modem & Router
Important Notice

Quick guide
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 (tablet, smart phone) 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: username: admin, password: admin
Ethernet
RipEX default IP is 192.168.169.169/24, so set a static IP 192.168.169.x/24 on your PC, power on the
RipEX and wait approximately 48 seconds for the RipEX OS to boot. Connect your PC to RipEXs' ETH
interface, start your browser and type https://192.168.169.169 in the address line.
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.
USB/ETH adapter
When accessing over the optional “XA” 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. You do not need to worry about
other RipEX'es, you will be connected to the local unit in all cases.
Wifi adapter
When accessing over the optional “W1” Wifi adapter, connect your PC (tablet, smart phone) to the
RipEX Wifi AP first. Its default SSID is “RipEX + Unit name + S/N”
Your PC will get its IP settings from the built-in DHCP server and you have to type http://10.9.8.7 in
your browser. Remaining steps are the same and you do not need to worry about other RipEX'es, since
you will be connected to the local unit in all cases.
RipEX Radio modem & Router – © RACOM s.r.o.8
Quick guide

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”).
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 (Section 7.6.3, “Ping”) to verify accessibility of all IP addresses
with which the unit will communicate.
9. Connect the SCADA equipment
7. Test your application
1http://www.racom.eu/eng/products/m/ripex/app/routing.html
9© RACOM s.r.o. – RipEX Radio modem & Router
Quick guide

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
- >200 kbps / 50 kHz, >100 kbps / 25 kHz, >50 kbps / 12.5 kHz, >25 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 COM ports over ETH controlled by Terminal servers. USB for independent service access
via USB/ETH adapter and for automatic FW and SW keys upgrade.
• Wifi management
- Any smart phone, tablet or notebook can be used as a RipEX portable display.
• 135–174; 215–240; 300–360; 368–512; 928–960 MHz
- Licensed radio bands
- Software-selectable channel spacing 50, 25, 12.5 or 6.25 kHz
• 10 watts
- Transmission output control, nine stages from 0.1 to 10 W. Hence QAM modulations (the highest
data speed) require a very linear RF power amplifier, max. 2 W is available for them.
• Energy saving
- Sleep mode – 0.1 W, controlled via a digital input.
- Save mode – 2 W, wakes 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
RipEX Radio modem & Router – © RACOM s.r.o.10
RipEX – Radio router

• Fast remote access
- Only the effective data are transferred from remote RipEX over the air, html page is downloaded
from the local unit.
• Bridge or Router
- RipEX is a device with native IP support which can be set as a standard bridge or router.
• Modbus, IEC101, DNP3, PR2000, Siemens 3964(R), Comli, RP570, C24, DF1, Profibus, SLIP,
Async Link, Cactus, ITT Flygt, RDS, UNI, Modbus TCP, IEC104, DNP3 TCP etc.
- Unique implementation of industrial protocols enables a secure addressed transmission of all
packets in all directions
• Three protocols on Radio channel
- Fully Transparent (Bridge)
- Flexible (Router) - for meshing networks providing unlimited footprint coverage without base stations
- Base driven (Router) - optimized for TCP/IP applications like IEC104 making them reliable and
stable even with a high number of RTUs.
• Backup routes
- When tested path between two RipEX IP addresses (even behind repeater or LAN) fails, automatic
switch-over to backup gateway behind Radio or Ethernet interfaces
- Unlimited number of prioritized backup gateways
- Instructional video http://www.racom.eu/ripex-backup
• VPN
- IPsec is a network protocol suite that authenticates and encrypts the packets of data sent over a
network.
- GRE is a tunneling protocol that can encapsulate a wide variety of network layer protocols inside
virtual point-to-point links over an Internet Protocol network.
• 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.
• TCP proxy
- Eliminates a transfer of TCP overhead over Radio channel when TCP overhead run locally between
connected device and RipEX on LAN. I.e. only payload (user) data are transferred further as UDP
(over Radio channel)
- Higher RipEX network bandwidth, no more problems with TCP timeouts
- Instructional video http://www.racom.eu/ripex-tcp-proxy
• ARP proxy
- RipEX can simulate any IP address (it may reply to any ARP request)
- This feature is typically used when RTU addresses behind different RipEX units are within the
same IP subnet and RTUs do not provide routing capabilities (neither default GW)
- Instructional video http://www.racom.eu/ripex-arp-proxy
• VLAN & Subnets
- RipEX can simulate any IP address (it may reply to any ARP request)
- Unlimited number of virtual Ethernet interfaces (IP aliases) can be set
• Embedded diagnostic & NMS
- Real time and historical (20 periods, e.g. days) statistics and graphs for the unit and its neighbours.
11© RACOM s.r.o. – RipEX Radio modem & Router
RipEX – Radio router

- 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
• Security
- 256 AES encryption, the most secure encryption meets FIPS 140 2 requirements
- 2048 (1024, 512) bit SSL certificate (even your own one) for https web configuration
• SW feature keys
Software authorization keys allow you to add advanced features when needed: Router mode, 166/83
(The two highest Data rates for 25 and 50 kHz channel spacing), COM2, 10 W, Backup routes
- 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 or from the built-
in GPS
- 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
• External Flash disc
- Automatic firmware upgrade, SW keys upload, configuration backup/restore, ssl certificate and
ssh keys upload and configuration, tech-support package download
RipEX Radio modem & Router – © RACOM s.r.o.12
RipEX – Radio router

2. RipEX in detail
2.1. Applications
Radio modem RipEX is best suited for transmission of a large number of short messages where a
guaranteed delivery 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.
To be able to satisfy different types of applications, RipEX offers multiple options for building a radio
network. There are 2 different Operation modes, Bridge and Router with 3 different protocols on Radio
channel:
•Transparent used in Bridge mode
•Flexible used in Router mode
•Base driven used in Router mode
2.2. Bridge mode
Bridge mode with fully transparent Radio protocol is suitable for all polling (request-response) applications
with star network topologies, however repeater(s) are possible.
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 RTUs 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.
13© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

Note
Limited broadcast 255.255.255.255 and Direct broadcast e.g. 192.168.255.255 as well as
Multicast (224.0.0.0 through 239.255.255.255) on Ethernet are supported and transferred
over the network.
You can see an instructional video explaining the Bridge mode functionality here: http://www.ra-
com.eu/ripex-bridge-mode
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 does not solve collisions. There is a CRC check of data in-
tegrity, however, i.e. once a message is delivered, it is 100% error free.
All the messages received from user interfaces (ETH&COM) 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).
One has to be very careful when RipEX in Bridge mode is connected to LAN, because all LAN traffic
is then broadcast to the Radio channel.
COM1,COM2 - All frames received from COM1(2) are broadcast over the radio channel and transmitted
to all COM ports (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) reply to a broadcast query from the master station. In such case massive collisions would ensue
because all substations (RTU) 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.
RipEX Radio modem & Router – © RACOM s.r.o.14
RipEX in detail

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.
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.
15© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

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…
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 same LAN, even if by accident (e.g. during maintenance).
RipEX Radio modem & Router – © RACOM s.r.o.16
RipEX in detail

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.
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:
17© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

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.18
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 2 independent interfaces: Radio and ETH. Each interface
has its own MAC address, IP address and mask.
IP packets are processed according to 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.
The additional Virtual COM ports and Terminal server can act as other IP router ports. This enables
Serial and TCP based RTUs to be combined in one network.
Two different Radio protocols are available in the Router mode: Flexible and Base driven.
• Flexible
Suitable for master or even multi master-slave polling and report by exception from remotes concur-
rently. No limits in network design – each radio can work as base station, a repeater, a remote, or
all of these simultaneously
• Base driven
This protocol is optimized for TCP/IP traffic and/or 'hidden' Remotes in report-by-exception networks,
when a Remote is not be heard by other Remotes and/or different Rx and Tx frequencies are used.
It is suitable for a star network topology with up to 255 Remotes under one Base station, where
each Remote can simultaneously work as a Repeater for one or more additional Remotes.
19© RACOM s.r.o. – RipEX Radio modem & Router
RipEX in detail

2.3.1. Router - Flexible, Detail description
Router mode with Flexible protocol is suitable for Multipoint networks of all topologies with unlimited
number of repeaters on the way, and all types of network traffic where Multi-master applications and
any combination of simultaneous polling and/or report-by-exception protocols can be used
Each RipEX can access the Radio channel spontaneously using sophisticated algorithms to prevent
collisions when transmitting to the Radio channel. Radio channel access is a proprietary combination
of CSMA and TDMA; the Radio channel is deemed to be free when there is no noise, no interfering
signals and no frames being transmitted by other RipEX stations. In this situation, a random selection
of time slots follows and a frame is then transmitted on the Radio channel.
Frame acknowledgement, retransmissions and CRC check, guarantee data delivery and integrity even
under harsh interference conditions on the Radio channel.
2.3.2. Router - Flexible, 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.
RipEX Radio modem & Router – © RACOM s.r.o.20
RipEX in detail