User Manual

OK
The incoming call was a VOICE
call and is now active.
proceed ahead
The call is answered with the appropriate type (VOICE or DATA) regardless of the
+FCLASS active setting. To distinguish between Data and Voice see the command response
or the extended format incoming call indication.
The Telit HE910V2 family provides the flow control method to avoid the unexpected data loss, while data
communication is activating via serial interface such as UART,USB.
Below table describes the flow control method can be selected in serial interface
SW Flow
control
(Xon/Xoff)
HW Flow
control
(RTS/CTS)
No Flow
control
Remark
UART1
O
O
O
Flow control method can be set by
AT\Q, AT&K , AT+IFC
USB MDM
O
Only support for RTS/CTS
USB AUX
O
No support flow control
USB AUX doesn’t support any flow control method. Therefore, this port isn’t suitable for
DATA service port. We recommend this port should be used only for AT command and URC
processing
In case TE sends RTS signal or XOff to Modem to stop data flow from Modem, Modem’s transmission can’t
be stopped, instantly. There are some delay times Modem process RTS signal.
Therefore, TE should prepare the guarding buffer after sending RTS signal or XOff to Modem to control data
flow. Below table describes the size of guarding buffer, according to serial interface and air access technology,
approximately
GSM/WCDMA
Circuit Service
GPRS/EGPRS/WCDMA
Packet Service
HSDPA
UART1
1 Kbyte
1.5 Kbyte
1.5 Kbyte
USB MDM
1 Kbyte
1.5 Kbyte
4 Kbyte
TE should prepare the guarding buffer more than the recommended buffer size to guarantee their data
transmission without the loss of data