There is a %Fax% PostScript device parameter WaitForDialTone which controls this. This is a boolean parameter which if set to FALSE, will permit the FAX card to do "blind dialing". If set to TRUE, the FAX card will insist on receiving a dial tone first. The following PostScript segment will set this parameter:
(%Fax%) <</WaitForDialTone false>> setdevparams
If you would like this setting to persist beyond power cycles, then the following PostScript code which exits the PostScript server loop, must precede the command line above:
serverdict begin 0 exitserver
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