Comtrol AT Commands - Manual (Page 109)

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
102184B Conexant 3-83
+ITF - Transmit Flow Control Thresholds
The +ITF command determines the flow control thresholds used by the modem for
transmit data from the DTE.
This optional compound parameter allows the DTE to determine the input buffer size in
the modem for data on circuit 103 (transmit data) from the DTE, to control the thresholds
used for flow control of such data, and to control how often the modem reports to the
DTE the number of octets in this buffer. The DTE can adjust its own thresholds for flow
control of data on circuit 104 (received data) from the modem.
Syntax
+ITF=[<off>[,<on>[,<report_period>]]]
Defined Values
<off> Determines the threshold, in octets, above which the modem
will generate a flow off signal. Applicable in Synchronous
Access and Frame Tunneling modes. Default <off> value is
255.
For the <on> and <off> subparameters, the input buffer is
assumed to reside between the modem’s V.24 interface and
the Synchronous Access protocol layer; i.e., the buffer count
includes all octets, including EM codes, received from the
DTE, with the exception of DC1 and DC3 if these are used to
signal <modem-by-DTE> flow control.
The modem returns the ERROR result code if the DTE
specifies that the <off> subparameter be set to a value less
than or equal to the <on> subparameter; in this case, the
current parameter value settings are not modified.
<on> Determines the threshold, in octets, below which the modem
will generate a flow on signal. Applicable in Synchronous
Access and Frame Tunneling modes. Default <on> value is
64.
<report_period> Not supported. A fixed value of zero is used and reported.
Reporting Selected Options
The modem sends a string of information text to the DTE consisting of selected
options in response to the following command:
+ITF?
The response is:
+ITF: <off>,<on>,<report_period>
Example:
+ITF?
+ITF: 255,64,0
Default values