RF-Link Technology NL6000 manual Over-the-Air Data Rates, Acknowledgements

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Best Choice: Mobile Data Mode

Because you expect a corrupt channel, use the mode that has the greatest amount of error control. Mobile Data mode includes three types of error control, Reed-Solomon forward error correction, error detection, and a block interleaver. This mode provides for maximum transmission reliability on a corrupt channel. Since the packet size is large, any data added to the packet to fill the interleaver is insignificant.

Because you are more likely to recover from transmission errors with Mobile Data mode, you can use a large Maximum Packet Size. A larger packet size can compensate for the lower percentage of user data in each packet and provide good throughput on a corrupt channel.

Why not use Basic Telemetry Mode for this scenario? Basic Telemetry mode is not useful when you expect a corrupt channel because it uses error detection only. Basic Telemetry mode cannot recover data errors, so throughput would be poor.

Why not use Enhanced Telemetry Mode for this scenario? Enhanced Telemetry mode provides error correction, but if both the signal strength and path are poor, you might need to reduce the Maximum Packet Size to increase reliability. With Mobile Data mode you can increase the Maximum Packet Size and get better throughput on a very corrupt channel.

5.6.2.Maximum Packet Size

The NL6000 transmits a data packet on the radio channel when the amount of data in the input buffer is equal to the Maximum Packet Size or when there is a timeout on the serial port. The maximum packet size is the largest amount of user data in one RF packet.

5.6.3.Over-the-Air Data Rates

The NL6000 supports two over the air data rates: 12,000 bps or 22,050 bps. Select the data rate you want to use depending upon the bandwidth you occupy and your license.

5.6.4.Acknowledgements

The NL6000 can request an acknowledgement (ACK) from the destination modem with each transmission. If this option is enabled, the unit will retransmit a packet up to a specified number of times if it does not receive an ACK. If it does not receive an ACK after the final retry, the unit will transmit the next packet. You specify the desired maximum number of retries with the Max Retries option.

Note: When acting as a repeater, the unit never generates an ACK. ACKs are end-to-end and do not affect the repeater unit.

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 Use the NL6000 in a Simple Configuration Product OverviewFeatures Configuration Templates Single and Multi- Point AddressingAcknowledgement Auto-TransmitSafety Warning Regulatory InformationFCC Part 406.0 to 406.1 MHz OperationSpecifications General SpecificationsUHF Radio Specifications Current Drain at 12Transmitter ReceiverVHF Radio Specifications Hardware Installation and Operation Power ConnectionsParts Description Serial PortDTE DCEAntenna Connection LEDsOperation LEDSoftware Configuration Technical SupportPrerequisites PreparationUnique Data Requirements for a Base Station Source and Destination AddressingBehavior of Repeater Units Addressing with WildcardsRepeat from a Base to a Remote Repeat to Multiple Remotes using Wildcard Transmission Mode Packet Data OptionsCRC FECRF Neulink NL6000 User Guide Over-the-Air Data Rates AcknowledgementsCarrier Sense Multiple Access DCD ModeSerial Connection to an I/O Device Basic Serial ParametersFactory Default Parameters Planning the RF ChannelPre- and Post-Data DCD Time Procedures Select Network ä Unit TypeGeneral Procedures Displaying the Configuration Summary Window Returning to the Previous MenuRadio Network Setup Setting the Unit Type Select Network ä Unit TypeSetting the Unit ID Myid Select Network ä Myid Setting the Target Unit ID ToidSerial Connection Setup Data Setup Setting the Packet Mode Select Network ä Packet ModeSetting the Data Rate Select Network ä Data Rate Setting the Request ACKs OptionSetting the Contention Option Select Network ä Contention Setting the Max Retries OptionRepeater Setup Trigger ID Value UseDownloading a Software Upgrade File ManagementSelect Save/Restore Parameters ä Save Parameters to Disk Saving Parameters to DiskRestoring Parameters from Disk Restoring Default Parameters Menu Quick Reference Main Menu Summary WindowSerial Menu DCD RS-232 SubMenu Network Menu Repeater SubMenu Radio Menu Diagnostics Menu Save/Restore Parameters Menu Troubleshooting Other ConsiderationsDuty Cycle Use a Fully-Wired RS-232 Cable Unit Does Not Enter Programming ModeUse a Slower Baud Rate Use a Faster Baud RateAppendix a Diagnosing and Correcting Performance Problems Setting the Frequency Trim includes setting PowerSetting the Power Value Select Diagnostics ä Transmit Continuous Random DataSetting the Deviation and Balance ∙ Select Frequency Trim from the Diagnostics menuSelect Diagnostics ä Transmit 100 Hz Square Wave ∙ Select Radio Ä Transmit Frequency for Active ChannelSetting the Receive Gain ∙ Select Deviation from the Diagnostics menu∙ Select Diagnostics ä Receive Diagnostic Mode ∙ Select Diagnostics ä Receive GainAppendix B Factory Default Parameters Category Parameter Default Value Custom ValueFactory Default Values Index RF Neulink NL6000 User Guide