Elpro Technologies 450U-E Wireless Ethernet Modem & Device Server User Manual
Rev Version 1.0.12-Beta7
www.cooperbussmann.com/wirelessresources
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Disable SSID broadcast.
(AP only)
This should be used to reduce bandwidth eavesdroppers from detecting the
radio network System Address (SSID) by passively listening to beacon
transmissions from the Access Point. When disabled, Access Points will not
transmit the System Address openly in Beacon messages. This is particularly
useful in unencrypted radio networks and where all stations know the SSID of
the Access Point.
Data Compression
Enable/Disable Data compression. See below for details
Save Changes
Save changes to non-volatile memory
Save Changes and
Reset
Save changes to non-volatile memory and activate the process
Data Compression
The radios incorporate a data compression algorithm based on RFC1951 specifications. This algorithm is similar to the
one used in file compression utilities such as PKZip, etc. which simply matches duplicate strings within the data frame
with pointers to previous data patterns. It keeps a running image of previous received data frames which it uses to
compare with the current data frame. When it finds a data string that is the same as a previous data string a pointer to
this location is sent instead of the data. Depending on the data this could considerably reduce the amount of data that
needs to be sent.
Performance is dependent on the type of data frames that are being sent. Typical improvements in throughputs that can
be expected when compression is enabled are:
15-40% improvement if using Modbus, depending on the radio baud rate
70% improvement for web page download
40% improvement if using FTP download
Serial Port Configuration
3.11
The 450U-E has an RS-232, and an RS-485 port which is used for serial communications. These ports may be used for
different purposes. The 450U-E offers three different serial functions, Modbus RTU Master, Expansion I/O and Modbus
RTU Slave
parameters.
Operating
Mode
Modbus RTU Master This mode should be configured when the port is
operating as a Modbus Master, i.e. Modbus RTU slave devices are connected
directly to the serial port.
Modbus RTU Slave This operating mode should be used if the port is being
used as a Modbus RTU slave, i.e. if a Modbus Master (DCS, Scada, etc.) is
connected to the serial port.
Expansion I/O This operating Mode should be selected when Elpro Serial
Expansion modules (115S-XX) are connected to the modem.
Date Rate
Serial date Rate. The data rate will need to be configured to match that of the serial
device that is connected and communicating via the port. Baud rates available from 110
to 230400 baud.
Data format
The Serial Data format defines the number of data bits, parity and start/stop bits that is
used to communicate with the serial device.
Flow Control
The Flow control is used by some serial devices to regulate the flow of data by turning
on/off flags that are used to tell the connected serial devices to start or stop transmitting
data. The RS232 supports CTC/RTS hardware flow control.
Max Num Units
to Poll
This is the maximum number of Modbus address that will be polled on the serial interface
when the port is configured for Expansion I/O. The default for RS232 is one and three
addresses will be polled on the RS485
Save Changes
and Activate
Save changes to non-volatile memory and activate the process
