Character Formats
The modem determines the DTE character format during the AT entry process.
Stop Bits
Commands may be sent to the modem with one or two stop bits: only the
first stop bit performs any function, and the second is ignored. The response
of the modem to the DTE always contains two stop bits. This is true in the
Idle and the Online Command State.
Data characters that are transmitted and received between the DTE and the
modem have the number of stop bits preserved except as modified due to overspeed
or underspeed conditions between the modems. The data bits may be modified
when the sending modem has to delete stop bits and the receiving modem shaves
(shortens) the stop bits to correct for an overspeed or an underspeed condition.
Length And Parity
Commands may be sent to the modem with any of the following data formats:
7-even (7 data bits and even parity bit), 7-odd, 7-mark, 7-space, 8-none,
8-even, 8-odd, and 8-space. The modem ignores the eighth data bit when interpreting
command characters. See S142 for online character
formats.
The word length and format of modem responses to DTE commands are determined
by the last AT command entered. The modem uses the same character format
as the DTE did during the last AT entry process.
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