Reading Available Hopping Channels - WAGO I/O-SYSTEM 750 Manual

194 Appendix
Return values
Parameters
MBX_RESULT
MBX_RSSI_VALUE
*)
750-644 I/O module or Bluetooth
12.3.7.7

Reading Available Hopping Channels

GetAvailableChannelMap, 0xD8
The call returns information on the status of the environment (i.e. the status of the
wireless medium) for a connection channel. For Bluetooth
for hopping are indicated. There are 79 channels with 1 MHz available. The
channels are numbered serially from 0 through 78. The frequency of each channel
is based on the channel number:
Frequency of the channel = 2402 + channel number MHz
The 750-644 I/O module supports AFH (adaptive frequency hopping). If
individual frequency ranges are recognized as defective (for example, if other
wireless technologies with higher signal strength in this range are sending), the
corresponding channels of its own transmission are excluded. This reduces
interference and improves the connection quality for the Bluetooth
well as for the third-party system. A positive side effect is the possibility of
making connections through third-party activity in the 2.4 GHz ISM band using
the list of the channels masked in this manner. The rule of thumb is: The greater
the number of channels available for hopping, the better the status of the wireless
medium.
Conditions
Mailbox size
6
-
Request
Byte
0
1
2
Value
MBX_CMD_OUT_OF_RANGE
MBX_CMD_GENERAL_ERROR The device
MBX_CMD_INVALID_ARG
-128 ... +127 (two´s complement)
®
SPP device
12 18 Config. Real-time Ad-hoc Master Slave
● ● -
7 6
2 2
MBX_GETAVAILABLECHANNELMAP
T
MBX_TARGET_TABLE_AND_INDEX
750-644 Bluetooth
Description
The index used is too large.
The device
valid target table was selected.
RSSI value for the requested
connection.
Mode Device role
● ●
5 4 3
2 2 2
-
Version 2.0.0, valid from FW/HW Version 03/03
WAGO-I/O-SYSTEM 750
®
RF-Transceiver
*)
is not connected.
*)
is not connected or no
®
the channels available
®
network as
Save
config.
● ● -
2 1
2 2
Reboot
-
0
2
Manual