Comtrol AT Commands - Manual (Page 168)

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
Conexant 102184B
4-14
+FCL - Carrier Loss Timeout
This parameter allows the DTE to select the modem’s loss-of-carrier delay between
initial loss-of-carrier and qualified loss-of-carrier, when the modem will give up and exit
a receive mode. Intermediate (less than FCL timeout) loss-of-carrier should be indicated
by insertion of the SQ-BAD signal quality indicator in the received data stream.
In unframed receive modes, if the modem detects RTC as described in Recommendation
T.30 prior to initial loss of the high speed carrier, or if the modem detects V.21 carrier
after initial loss of high speed carrier, then the modem immediately accepts the loss-of-
carrier as qualified, without waiting for the FCL timer to expire.
In HDLC receive modes, if the modem detects HDLC abort prior to initial loss of the
high speed carrier, or if the modem detects V.21 carrier after initial loss of high speed
carrier, then the modem l immediately accepts the loss-of-carrier as qualified, without
waiting for the FCL timer to expire.
Write Syntax
+FCL=<time>
Defined Values
<value> Decimal number representing the loss-of-carrier delay time in
units of 100 ms. The range is 0 - 255.
Reporting Current or Selected Values
Command: +FCL?
Response: +FCL: <time>
Example: +FCS: 0 For the default setting.
Reporting Supported Range of Parameter Values
Command: +FCL=?
Response: +FCL: ( <time> range)
Example: +FCL: (0-255)