3.3.4.2RTS Threshold

RTS Threshold is the frame size above that an RTS/CTS handshake will be per- formed before attempting to transmit. RTS/CTS ask for permission to transmit to reduce collisions, but add considerable overhead. Disabling RTS/CTS can reduce overhead and latency in WLANs where all stations are close together, but can increase collisions and degrade performance in WLANs where stations are far apart and unable to sense each other to avoid collisions. If you are experiencing excessive collisions, you can try turning RTS/CTS on or (if already on) reduce RTS/CTS Threshold on the affected stations.

3.3.4.3Fragment Threshold

Fragmentation Threshold is the maximum length of the frame, beyond which payload must be broken up into two or more frames. Collisions occur more often for long frames because sending them occupies the channel for a longer period of time, increasing the chance that another station will transmit and cause a collision. Reduc- ing Fragmentation Threshold results in shorter frames that "busy" the channel for shorter periods, reducing packet error rate and resulting retransmissions. However, shorter frames also increase overhead, degrading maximum possible throughput, so adjusting this parameter means striking a good balance between error rate and throughput.

3.3.4.4Preamble Type

A preamble is a signal used in network communications to synchronize the transmis- sion timing between two or more systems. Proper timing ensures that all systems are interpreting the start of the information transfer correctly.

3.4Setting Serial Parameters

This section explains how to configure EKI-1351/1352 serial communication parameters using this utility. There are various operation modes that are suitable for different application.

Click on the "+" before the model name (e.g. EKI-1522), and the utility will expand the tree structure to show the individual device name. And click on the “+” before the device name, and the utility will expand the interfaces on this device server. Select the serial interface.

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Advantech EKI-1352, EKI-1351 manual Setting Serial Parameters, RTS Threshold, Fragment Threshold, Preamble Type