RF-Link Technology manual RF Neulink NL6000 User Guide

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it contains the least amount of overhead and the highest percentage of user data in each packet. Basic Telemetry mode provides the highest throughput on a clean channel.

However, if there is a transmission error, you will lose the entire packet. Therefore, when using Basic Telemetry mode, use a smaller Maximum Packet Size so that you lose very little user data if an error does occur. In this situation, smaller packets have a better chance of getting through.

Why not use Enhanced Telemetry Mode or Mobile Data Mode for this scenario? If the channel is clean and the signal is strong, there is no need to use a mode that reduces the percentage of user data in each packet.

Scenario #2

Description: You have average signal strength or a less reliable path between the radio modem units. You expect occasional corruption on the radio data link from noise bursts, RF interference, or signal fading.

Best Choice: Enhanced Telemetry Mode

Because you expect the channel to have occasional corruption, use Enhanced Telemetry mode. In addition to error detection, Enhanced Telemetry mode uses Reed-Solomon forward error correction for increased transmission reliability. This mode requires more overhead than Basic Telemetry mode and lowers the percentage of user data in each packet.

However, because you are less likely to lose data with Enhanced Telemetry mode than with Basic Telemetry mode, you can use a larger Maximum Packet Size. A larger packet size can compensate for the lower percentage of user data in each packet and provide good throughput on an occasionally corrupt channel.

Why not use Basic Telemetry Mode for this scenario? Basic Telemetry mode is not useful when you expect a corrupt channel because a single transmission error will cause a packet failure. Lost packets will degrade throughput. Basic Telemetry mode cannot recover data errors, so throughput would be poor.

Why not use Mobile Data Mode for this scenario? Mobile Data mode requires that the interleaver be filled for each packet. If the data packets are smaller than the interleaver size, throughput will suffer because the interleaver is ￿filled￿ prior to transmission. Since fading is not a big issue in this scenario, the interleaver is not necessary.

Scenario #3

Description: You have fluctuating signal strength and a less reliable path between the radio modem units. You expect noise bursts, RF interference, or signal fading to corrupt the radio data link. The remote unit is moving, or it is located in an area where the surroundings are moving, such as a busy street.

RF Neulink

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NL6000 User Guide

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Contents NL6000 Wireless Modem Copyright Table of Contents RF Neulink NL6000 User Guide RF Neulink NL6000 User Guide Product Overview Use the NL6000 in a Simple ConfigurationFeatures Auto-Transmit Configuration TemplatesSingle and Multi- Point Addressing Acknowledgement406.0 to 406.1 MHz Operation Safety WarningRegulatory Information FCC PartGeneral Specifications SpecificationsReceiver UHF Radio SpecificationsCurrent Drain at 12 TransmitterVHF Radio Specifications Serial Port Hardware Installation and OperationPower Connections Parts DescriptionDCE DTELED Antenna ConnectionLEDs OperationPreparation Software ConfigurationTechnical Support PrerequisitesSource and Destination Addressing Unique Data Requirements for a Base StationAddressing with Wildcards Behavior of Repeater UnitsRepeat from a Base to a Remote Repeat to Multiple Remotes using Wildcard Packet Data Options Transmission ModeFEC CRCRF Neulink NL6000 User Guide Acknowledgements Over-the-Air Data RatesBasic Serial Parameters Carrier Sense Multiple AccessDCD Mode Serial Connection to an I/O DevicePre- and Post-Data DCD Time Factory Default ParametersPlanning the RF Channel Select Network ä Unit Type ProceduresGeneral Procedures Returning to the Previous Menu Displaying the Configuration Summary WindowSetting the Target Unit ID Toid Radio Network SetupSetting the Unit Type Select Network ä Unit Type Setting the Unit ID Myid Select Network ä MyidSerial Connection Setup Setting the Packet Mode Select Network ä Packet Mode Data SetupSetting the Max Retries Option Setting the Data Rate Select Network ä Data RateSetting the Request ACKs Option Setting the Contention Option Select Network ä ContentionTrigger ID Value Use Repeater SetupFile Management Downloading a Software UpgradeRestoring Parameters from Disk Select Save/Restore Parameters ä Save Parameters to DiskSaving Parameters to Disk Restoring Default Parameters Main Menu Summary Window Menu Quick ReferenceSerial Menu DCD RS-232 SubMenu Network Menu Repeater SubMenu Radio Menu Diagnostics Menu Save/Restore Parameters Menu Duty Cycle TroubleshootingOther Considerations Use a Faster Baud Rate Use a Fully-Wired RS-232 CableUnit Does Not Enter Programming Mode Use a Slower Baud RateSelect Diagnostics ä Transmit Continuous Random Data Appendix a Diagnosing and Correcting Performance ProblemsSetting the Frequency Trim includes setting Power Setting the Power Value∙ Select Radio Ä Transmit Frequency for Active Channel Setting the Deviation and Balance∙ Select Frequency Trim from the Diagnostics menu Select Diagnostics ä Transmit 100 Hz Square Wave∙ Select Diagnostics ä Receive Gain Setting the Receive Gain∙ Select Deviation from the Diagnostics menu ∙ Select Diagnostics ä Receive Diagnostic ModeFactory Default Values Appendix B Factory Default ParametersCategory Parameter Default Value Custom Value Index RF Neulink NL6000 User Guide
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