The Leader in Industrial Data Communication Solutions

1. The Leader in Industrial Data Communication Solutions Training: RF Path – Will it work?

2. RF Design: Will this work? RF Path 12 miles

3. RF Design: SRM Radios • 900MHz constants • RF Path Loss with LOS: • First mile: -96dB • Each doubling of range: -6dB • Transmitter Power: 1watt or 30dB • Receiver Sensitivity: -108dB @ BER 1E-6 • 2.4GHz constants • RF Path loss with LOS: • First mile: -106dB • Each doubling of range: -6dB • Transmitter Power: 500milliwatts or 27dB • Receiver Sensitivity: -108dB @ BER 1E-6

4. RF Design: Throughput • Fact - Distance decreases throughput • To maximize radio throughput and reliability: • Maximize RF quality (shorter coax, higher gain antennas) • If practical, don’t use store-and-forward repeaters. Use back-to-back repeaters? • Use point-to-point architecture • To minimize system throughput requirements: • Avoid cross-network data movement • Only retrieve data once (Client/Server HMI model) • Avoid HMIs as slaves • Exchange data in large groups rather than several smaller groups (minimize protocol overhead) • Minimize data needed and increase update period

5. RF Design: Antennas (1) • Use radio manufacturer approved antennas • Common types: • Directional (yagi, parabolic) • Omni-directional (di-pole) • Gain is specified in dBd or dBi and achieved by directing (focusing) RF emission • Emission patterns must be considered such that other sites are within focused area

6. RF Design: Antennas (2)

7. RF Design: Coax (1) • Data-Linc offers two piece coax assembles: • Good price/quality ratio • Flexibility at radio mount position • Lightning protection ready • Bulkhead pass-through ready • Data-Linc only sells coax with end connectors that are inert gas welded, vapor sealed, and tested • Do not cut to length! Coil excess

8. RF Design: Coax (2) • Data-Linc uses Times Microwave Coax • Website: www.timesmicrowave.com • Losses: • COAX900MHz2.4GHzLMR240 7.6dB/100foot 12.9dB/100footLMR400 3.9dB/100foot 6.8dB/100foot • Failure Modes • Improper end connections • Moisture penetration • Crimped, collapsed

9. RF Design: Other RF Losses • SMA and N-Type Connectors • Loss: .5dB each junction • Lightning Arrestors • Always recommended for outdoor applications • Install near equipment to be protected • Loss: .1dB typical

10. RF Design: EIRP • Effective Isotropic Radiated Power (EIRP) • Set by government regulation • This is maximum measured RF emission from an antenna • In most countries not to exceed 4 watts • Discussion: 1 watt can be increased to 4 watts by doubling the power twice (1w x 2 x 2 = 4w). A doubling of power equals 3dB, thus, doubling twice is 6dB. This means a 6dB gain antenna can be directly connected to a 900MHz radio to emit the maximum legal EIRP.

11. RF Design: Fade Margin • This is the amount of RF signal strength exceeding the minimum needed for a specified receive sensitivity. • Desired fade margin minimums: • 20dB for SRM serial radios • 30dB for SRM Ethernet radios

12. RF Path Theory Example 1 • What is the fade margin – Will it work? 3dB Omni 3dB Omni 25 miles (40.2km) 50 feet LMR400 50 feet LMR400 -108 dB Receive sensitivity 30dB Transmit