Specifications
    Chapter 2 – Fax Class1 Commands 
Multi-Tech Systems, Inc. SocketModem MT5600SMI/MT5656SMI Reference Guide (S000306B)  70 
Service Class 1 Commands 
Command:  +FAR  Adaptive Reception Control 
Description:    If Adaptive Reception is enabled, the modem adaptively detects the selected 
message carrier or V.21 control messages. If the expected carrier is detected, 
the modem operates as specified in the respective +FRM=<mod or 
+FRH=<mod commands. If V.21 flag preamble is detected instead, the 
modem issues a +FRH:3 intermediate result code, and then executes an 
implied +FRH=3 command. 
Defined Values:   <value> Decimal number corresponding to the selected option. 
    0 Disable Adaptive Reception. (Default.) 
    1 Enable Adaptive Reception. 
Reporting Current or Selected Values: 
 Command: +FAR? 
    Response: +FAR: <value 
    Example: +FAR: 0 For the default setting. 
Reporting Supported Range of Parameter Values: 
 Command: +FAR=? 
    Response: +FAR: (<value> range ) 
    Example: +FAR: (0,1) 
Command:  +FCL  Carrier Loss Timeout 
Description:    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. 
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) 










