Siemens SIMATIC NET SCALANCE W780 Series Configuration Manual page 275

● max. Tx Power
Specify the maximum possible transmit power of the device.
If the transmit power is set too high the received signal at the client may be
overmodulated. Check the received signal strength at the client (dBm).
It may be necessary to reduce the transmit power depending on the antennas being used
to avoid exceeding the maximum legal transmit power. Reducing the transmit power
effectively reduces cell size.
Note
The maximum possible transmit power varies depending on the channel and data rate.
For more detailed information on transmit power, refer to the documentation
"Characteristics radio interface".
Note
If both interfaces of access points with two WLAN interfaces are operated in the same
frequency range, this may cause wireless interference on one or both interfaces at a
transmit power higher than 15 dBm.
● Tx power check
Indicates whether the settings that have been made will violate the permitted transmit
power restrictions of the selected country. The following parameters influence this
calculation:
max. Tx Power, Antenna Gain, Additional Attenuation.
The following displays can appear:
– Allowed
– Not Allowed (Some Channels)
– Not Allowed (All Channels)
– Controlled automatically by iREF.
Procedure
1. To configure the WLAN interface, you must always specify the country first. Select the
country in which the device will be operated from the "Country Code" drop-down list.
2. Select the required frequency band from the "Frequency Band" drop-down list.
3. From the "WLAN Mode" drop down list, select the required transmission standard for the
configured frequency band.
4. Click the "Set Values" button.
SCALANCE W780/W740 to IEEE 802.11n Web Based Management
Configuration Manual, 08/2018, C79000-G8976-C267-13
The channels can be used with the current settings.
Among the channels, there are some on which the current transmit power exceeds the
maximum permitted transmit power.
No permitted operation is possible. The transmit power is too high.
Controlled by the iREF function.
Configuring with Web Based Management
6.6 "Interfaces" menu
275