Serial Settings - Advantech EKI-1351 User Manual

3.3.3.2 RTS 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.
3.3.3.3 Fragment 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.
3.3.3.4 Preamble 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.
3.4

Serial Settings

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.
35 EKI-1351/1352 User Manual