Advantech EKI-1352 User Manual
Authentication Type: There are three kinds of types in this drop-down menu
– Open system: No encryption for network communication. You can neglect the
key setting on the right side.
– WEP Share Key: Both communication devices use the same key as encryp-
tion.
– Automatic: Detect the WEP situation of the access point automatically. EKI-
1351 and EKI-1352 will use the current key for encryption. If EKI-1351/1352’s
key does not coincide with the access point’s key, the user should reset the
same key and reboot to connect.
Chapter 3 Configuring Serial Device Server
Encryption: If the system needs WEP encryption, the user has to set the key
type. There are two kinds of encryption keys: 64 bits and 128 bits. For an open
system, the encryption function is disabled.
Set the key format. The table shows the allowed characters and length of the
different key index and key formats.
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Alphanumeric Hexadecimal
64 bits Up to 5 random characters
on the keyboard
128 bits Up to 13 random characters
on the keyboard
Index: This lists the supported encryption keys that you can choose from
3.3.2.4 Wireless Advanced
The tab identifies several parameters that are related to the 802.11b/g wireless network. We strongly suggested the default settings are not changed unless necessary.
If you want to recovery to factory value, you click the “Reset to factory default value”.
Up to 10 random hexadecimal
characters (0 ~ 9, a ~ f)
Up to 26 random hexadecimal
characters (0 ~ 9, a ~ f)
Parameters Default Value Range
Beacon Interval 100 0~65535
RTS Threshold 2347 0~2347
Fragment Threshold 2346 256~2346
Preamble Long Long/Short
3.3.2.5 Beacon Interval
In infrastructure networks, the access point periodically sends beacons. You can set
the beacon interval with the access point configuration screen. In general, the beacon interval is set to 100 ms, which provides good performance for most applications.
In ad hoc networks, there are no access points. As a result, one of the peer stations
assumes the responsibility for sending the beacon. After receiving a beacon frame,
each station waits for the beacon interval and then sends a beacon if no other station
does so after a random time delay. This ensures that at least one station will send a
beacon, and the random delay rotates the responsibility for sending beacons.
EKI-1351/EKI-1352/EKI-1521/1522/1524 User Manual 46
By increasing the beacon interval, you can reduce the number of beacons and associated overhead, but that will likely delay the association and roaming process
because stations scanning for available access points may miss the beacons. You
can decrease the beacon interval, which increases the rate of beacons. This will
make the association and roaming process very responsive; however, the network
will incur additional overhead and throughput will go down. In addition, stations using
power save mode will need to consume more power because they’ll need to awaken
more often, which reduces power saving mode benefits.
3.3.2.6 RTS Threshold
RTS Threshold is the frame size above that an RTS/CTS handshake will be performed before attempting to transmit. RTS/CTS ask for permission to transmit to
reduce collisions, but adds 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.
3.3.2.7 Fragmentation 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. Reducing 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.
Chapter 3 Configuring Serial Device Server
3.3.2.8 Preamble
A preamble is a signal used in network communications to synchronize the transmission timing between two or more systems. Proper timing ensures that all systems are
interpreting the start of the information transfer correctly.
3.4 3.4 Setting serial parameters
This section explains how to configure Advantech serial device server serial
communication parameter 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.
47 EKI-1351/EKI-1352/EKI-1521/1522/1524 User Manual
3.4.1 Setting serial port parameters
Click on the “+” before the device name, and the utility will expand the interfaces on
this device server. Select the one serial interface.
Description: You can give a more detailed description on the function of the port
for easier management and maintenance. Descriptions have a limit of 128 characters.
EKI-1351/EKI-1352/EKI-1521/1522/1524 User Manual 48
Type: The EKI serial device servers offer three kinds of serial protocols, RS-
232, RS-422 and RS-485. You can use any of the three serial protocols according to your requirements.
Chapter 3 Configuring Serial Device Server
Baud Rate: The EKI serial device servers support baud rates from 50 to
921.6Kbps. Total throughput up to 1.2M bps
Parity: The EKI serial device servers provide five options: None, Odd, Even,
Space, Mark.
Databit: The EKI serial device servers provide four options: 5, 6, 7 or 8.
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Stopbits :The EKI serial device servers provide three options: 1, 1.5 or 2.
Flow Control: The EKI serial device servers provide four options: None, Xon/
Xoff, RTS/CTS, DTR/DSR.
3.4.2 Setting Virtual COM Operating Mode Parameters
The Advantech serial device servers extend traditional COM ports of a PC to Ethernet access. Through Ethernet networking, users can control and monitor remote
serial devices and equipment over LAN or WAN. Advantech serial device servers
come with a COM port redirector (Virtual COM driver) that transmits all serial signals
intact. This means that your existing COM-based software can be preserved, without
modifying to fulfill the needs. The Virtual COM mode allows user to continue using
RS-232/422/485 serial communications software that was written for pure serial communication applications.
EKI serial device servers come with COM port redirector(virtual COM driver) that
work with Window NT/2000/XP/Vista(X86) systems. The driver establishes a transparent connection between host and serial device by mapping the IP of Advantech
serial device server serial port to a local COM port on the host computer.
EKI serial device server provides Multi-access function through one Ethernet
connection path or dual Ethernet connection path. Allow the max. of five connections
to open one serial port simultaneously. In the mode, all connection have to use the
same serial setting. If one serial setting of these connections is different from others,
the data communication may operate incorrectly.
EKI-1351/EKI-1352/EKI-1521/1522/1524 User Manual 50
Host Idle Timeout: 10~255 second. The default vale is 10 second. The main
purpose of Host Idle timeout is when the idle happens and continues more than
the set value, the utility will cut off the connection between serial device servers
and the host automatically. You must re-connect to recover the communication.
EKI serial device server provides Multi-access function through one Ethernet
connection path or dual Ethernet connection path. Allow the max. of five connections
to open one serial port simultaneously. In the mode, all connection have to use the
same serial setting. If one serial setting of these connections is different from others,
the data communication may operate incorrectly.
There are two operating mode of Multi-access function. One is Normal mode;
another is Round-Robin mode.
Normal mode: disabling “Response Timeout” parameter, EKI serial device sev-
ers will operate in “normal mode”. When multiple hosts open the serial port
simultaneously, the EKI serial device server only offers control ability for the first
connected host and provides data communication function for others. Each
serial port supports up to five simultaneous connections, so multiple hosts can
transmit/receive data to/from the same serial port simultaneously. Every host
can transmit data to the same serial port, an
transmit data to every hosts. When the multiple hosts transmit data to the same
serial port at the same time, the received data from Ethernet and the outputs of
serial port are mixed. When EKI serial device server receives data from serial
port, the data will also be transmitted to the connected hosts simultaneously.
d EKI serial device server will also
Chapter 3 Configuring Serial Device Server
Note This operating mode is especial suitable for that one major host send the
command and others hosts just listen the data from serial port. If two of connected hosts send the command at the same time, it is possible that EKI
serial device server will not handle the command and will response the incorrect data.
51 EKI-1351/EKI-1352/EKI-1521/1522/1524 User Manual
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