Weidmuller WI-MOD-945-E: 900Mhz Wireless Ethernet & Device Server v2.16 - Manual (Page 40)

Weidmuller Wireless Ethernet Modem & Device Server WI-MOD-945-E User Manual
Page 40 www.weidmuller.com Rev 2.136
Interference Mitigation
(AP only)
Interference Mitigation should only be turn on (Default is Off) if using Demo
Whip antenna’s or if there is a high level of background interference.
By enabling this option the radio will dynamically adjust radio parameters to
help mitigate interference based on any background interference. It will reduce
the receiver sensitivity and so should only be enabled on paths with a high
fade Margin and good signal quality, etc.
Bursting Selecting this option can increase the data throughput by reducing the
overheads associated with wireless transmissions.
Enable Iperf Server Enable Iperf Server function in the modem. Iperf is used for performing Radio
surveys or radio path testing. See section 4.4 -
“ Throughput Test ”
Fixed Noise Floor Allows the Radio Receiver Noise Floor (and therefore sensitivity) to be moved
above any interference. What this will do is essentially stop the radio
communicating with devices with lower signal strength. For use in areas where
there is a greater amount of interference
Fixed Noise Floor
900MHz FHSS band can have many sources of interference. This interference can sometimes be a problem due to the
way 802.11 devices communicate. Standard 802.11 communications uses a system called “Clear Channel Assessment”
which means the radio will listen before transmission and if the channel is busy it will hold off regardless of the level of
signal.
If the background interference is high due to other radio systems or noise you can raise the Fixed Noise floor to
compensate. The Channel Utilisation page can be used to identify excess noise / interference.
Raising the Noise Floor will block out any receive signal levels below the value configured under “Fixed Noise Floor “on
the Advanced Radio Configuration page. The value must be entered as a negative dBm number and should be at least
8dB greater than the weakest RSSI of any connected modems, otherwise communications may be lost.
E.g. if the interfering noise levels are around -80 dB you can raise the Noise floor to -70dB to block out any signals below
making sure the RSSI levels of any connected modules are not below this Noise Floor as they will not communicate.
The Connectivity page can be used to determine what other systems are around and what their RSSI levels are.
After configuring the fixed noise floor, confirm that the Channel Utilisation has dropped to a desirable level, and where
possible perform an iperf Throughput Test to confirm acceptable performance.
3.10 - Serial Port Configuration
The WI-MOD-945-E has an RS-232, and an RS-485 port for serial communications. These ports may be used for
different purposes. The WI-MOD-945-E offers three different serial functions, which are PPP server; Serial Gateway; and
Modbus TCP to RTU Gateway.
RS-232 PPP Server
The WI-MOD-945-E can be used as a PPP (Point-to-Point Protocol) Server to connect the wireless system to serial
devices via the RS232 or RS485 serial ports.
PPP Server enables a network connection to the WI-MOD-945-E over a serial cable. This is much like dial up internet.
The maximum serial data rate is 115,200bps. Hardware or Software flow control may be selected.
With minimal configuration on the PC, you may use Dial up networking in Windows XP to connect to the network via the
serial port.
For the WI-MOD-945-E, users must configure the local IP address for the WI-MOD-945-E and the remote device IP
address. Some care must be taken in selecting these IP addresses.