WMO2 G900 / G1800 / G1900
WCOM/GSM/WMO2/WMO2ATDOC
Friday 21 May 1999
WAVECOM confidential ©
71
4.9.3
DTE-DCE local flow control
+IFC
This command is used to control the operation of local flow control
between the DTE and DCE.
AT+IFC=<DCE_by_DTE>,<DTE_by_DCE>
* < DCE_by_DTE >:
0
none
supported
1
Xon/Xoff local circuit 103
not supported
2
RTS
supported
3
Xon/Xoff global on circuit 103
not supported
Important note: when this parameter is set to 2 (DTE invokes flow control
through RTS) the behavior of the DCE is the following:
If the DCE has never detected RTS in high (or ON) condition since startup
then it ignores RTS, assuming this signal is not connected.
As soon as DCE detects RTS high, then this signal acts upon it. Therefore
subsequent RTS transition to OFF will prevent DCE from sending any
further data in online and in offline as well.
This behavior allows the user to use the default settings (hardware flow
control) and let RTS disconnected. In the case RTS is connected and is high
at least once then it acts upon DCE.
* < DTE_by_DCE >:
0
none
supported
1
Xon/Xoff circuit 104
not supported
2
CTS
Supported
When this parameter is set to 0 (none) then CTS is kept high all the time.
Application to GSM
AT+IFC?
GSM to application
+IFC: 2,2
OK
current values
Application to GSM
AT+IFC=?
GSM to application
+IFC: (2),(2)
OK
possible values.
Application to GSM
AT+IFC=0,0
GSM to application
OK
new values
4.9.4
Set DCD signal &C
This commands controls the Data Carrier Detect (DCD) signal.
Application to GSM
AT&C0
DCD always on
GSM to application
OK
command valid
Application to GSM
AT&C1
DCD matches state of the remote modem's data carrier
GSM to application
OK
command valid
4.9.5
Set DTR signal &D
This commands controls the Data Terminal Ready (DTR) signal.
Application to GSM
AT&D0
the DTR signal is ignored
GSM to application
OK
command valid
Application to GSM
AT&D1
Modem switches from data to command mode when DTR
switches from ON to OFF
GSM to application
OK
command valid
Application to GSM
AT&D2
Upon DTR switch from ON to OFF, the call is cleardown
GSM to application
OK
command valid