Sends text data to specified device.
The destination device ID can be in the range 0 to 255, where 255 specifies broadcasting.
The sender device ID can be in the range 0 to 255, where 255 causes the device ID of this device to be set automatically.
The maximum length of data is 1448 bytes. The end of the data is indicated by a CR (carriage return).
@TXT(Destination device ID<3 digits>)(Sender device ID<3 digits>)(Text data) CR
No response
=>"@TXT002001", "HELLO" CR
Sends the 5 characters "HELLO" to the device with device ID 002.