Special Call Setup Conditions

Leased Line
FAX modem operation on leased lines is not supported.

MI-MIC Control
FAX calls established by MI-MIC lead control is for further study; not supported.

Reverse Modes
The &A command and R dial modifier are valid for FAX calls.

V.25bis Commands
V.25bis commands are not compatible with FAX Class 1 or Class 2.0. Therefore, Hayes modems operate as if the value of +FCLASS were 0 when V.25bis commands are enabled.

S Registers
The following S registers do not affect modem behavior while in the FAX mode:

S18         S26         S30          S36         S37  


S44         S46         S48          S49         S50  


S53         S55         S57          S69         S82  


S84         S93         S94          S95

Register S47 is set to the value 0 when the modem is on line in the FAX mode. The register normally indicates the type of data connection that has been established.

Register S85 is set to 0 after a FAX call has been established.

Register S86 is set to 1 if a hangup occurs while the modem is in

the FAX mode. The value 1 is a new value for S86.

The modem does not accept V.25bis commands while in the FAX mode. Since selection of the FAX mode requires use of an AT command, the modem will have to be in AT command mode before issuing the +FCLASS=1 (or 2.0) command.

The HS lamp is on while the modem is in the FAX mode. The SD and RD lamps indicate DTE interface activity, as they do in the data mode.

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