Locking the Port Speed (DCB)
A DCB entry locks the modem's port speed to a specific default. It also controls XON/XOFF software flow-control settings.
The following example of a DCB entry is from the sample INF file, MdmHayes.inf:
; DCB's - DWORDS and words are byte reversed.
; ByteSize (Number of bits/byte, 4-8).
; Parity (0-4=None,Odd,Even,Mark,Space). StopBits (0,1,2 = 1, 1.5, 2)
; |DCBLength |BaudRate |Bit Mask
HKR,, DCB, 1, 1C,00,00,00, 80,25,00,00, 15,20,00,00, <cont. next line>
;|Rsvd |XonLim|XofLim| | | |Xon|Xof|Err|Eof|Evt
00,00, 0a,00, 0a,00, 08, 00, 00, 11, 13, 00, 00, 00 <end DCB line>
The comment lines in the preceding example describe all the fields in the DCB line. Typically, the only field that is modified is the baud rate. The other fields are used in advanced applications, which are beyond the scope of this document.