S42/Central Software User Guide
1VV0301318 Rev. 3
– 2018-08-31
Reproduction forbidden without written authorization from Telit Communications S.p.A.- All Rights Reserved.
Page 24 of 66
3.2.1.1.
Enable the Multiplexing Mode
As default the S42/Central communicates to the serial interface in the AT command
mode. This is the default behavior of the S42/Central.
To enable the multiplexing mode during the run time it is required to send the following
command:
AT+BMUX=1
OK
After this initial command the S42/Central reports the response “OK” in the AT
command mode and then changes to the multiplexing mode. All exchanged data requires to be
sent in the defined MUX packet framing.
The multiplexing response message of the S42/Central may be sent in several MUX
frames.
The MUX mode can be left with the AT command “AT+BMUX=0” or a reset of the
S42/Central device.
Note: The following example in the MUX mode is listing the serial data in hexadecimal
coded form to identify the MUX framing. For a better understanding the
corresponding text message (human readable) is added in italic letters.
3.2.1.2.
Create GATT Connection
To establish a GATT connection to a peripheral device it is required to initiate a call request to
the unique Bluetooth address.
cc ff 18 41 54 44 30 30 38 30 32 35 30 30 31 32 34 31 2c
74 32 2c 47 41 54 54 0d
ATD008025001241,t2,GATT
cc ff 0e 0d 0a 43 4f 4e 4e 45 43 54 20 47 41 54 54
cc ff 05 20 30 78 31 30
cc ff 02 20 3c
cc ff 0c 30 30 38 30 32 35 30 30 31 32 34 31
cc ff 05 20 30 78 30 32
cc ff 01 3e
cc ff 02 0d 0a
CONNECT GATT 0x10 <008025001241 0x02>
The S42/Central reports the created GATT connection with the result message
„CONNECT“ include the connection type „GATT“ and a connection handle “0x10”.
This connection handle is not set to a fixed value and will be different for each connection.
The given connection handle is required for further activities onto this peripheral device.
