Special Coexistence Properties; Figure 6: Adaptive Frequency Hopping (Afh) - WAGO 750-921 Manual

28 Function Description
4.6

Special Coexistence Properties

Bluetooth
use from 2.4 GHz for data transfer. This frequency band is also used by devices
that use other technologies such as WLAN in accordance with IEEE 802.11 b/g.
To minimize interference, Bluetooth
coexistence mechanisms:
Frequency Hopping Spread Spectrum (FHSS)
•
When transmitting, the frequency is switched up to 1600 times per second.
The actual narrowband radiant power (1 MHz channel bandwidth) is
distributed time-averaged over a wide band (79 MHz).
Adaptive Frequency Hopping (AFH)
•
If interference occurs from other radio systems (see figure, violet),
Bluetooth
transmissions (red transparent). Radio systems that do not support the
automatic adjustment can continue to use these frequencies.

Figure 6: Adaptive Frequency Hopping (AFH)

Adaptive Transmit Power
•
If there is a connection between two Bluetooth
strength, the devices automatically reduce their transmit power.
The specified mechanisms are used automatically by the WSA. Beyond the
mechanisms contained in the standard, the device provides other setting options to
further improve coexistence that can be configured via AT commands:
®
technology uses the unlicensed ISM frequency band for international
®
systems (blue/red) can avoid the affected channels in future
750-921 Bluetooth
®
technology offers the following effective
®
devices with a high signal
Version 2.0.1, applicable from FW Version 02
WAGO-I/O-SYSTEM 750
®
Adapter
Manual