Control Microsystems 5901 - Esr=N - Selective Repeat

5901 High Speed Dialup Modem Hardware Manual
October 19, 2007
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0 In Framed sub-Mode, modem transmits abort on underrun in middle of frame
(default).
1 In Framed sub-Mode, DCE transmits a flag on underrun in middle of frame, and
notifies DTE of underrun or overrun.
d Specifies whether or not, in V.34 half-duplex operation, additional procedures besides those
specified in § 12/V.34 shall be performed by the modem when switching from primary
channel to secondary channel operation, and vice versa. This subparameter should not be
commanded.
e Specifies the CRC polynomial used while operating in Framed sub-Mode. The options are:
0 CRC generation and checking disabled (default).
1 In Framed sub-Mode, the 16-bit CRC is generated by the modem in the transmit
direction, and checked by the modem in the receive direction.
f Specifies if Non Return to Zero Inverted (NRZI) encoding is to be used by the modem for
transmit and receive data. The options are:
0 NZRI encoding and decoding disabled (default and fixed).
g, h Specifies the octet value(s) to be used while performing character-oriented framing, where g
is to be commanded to 255 (FFh); h is not to be commanded.
Reporting Selected Options
The modem reports the selected options in response to the following command:
Command: +ESA?
Response: +ESA:a,b,c,d,e,f,g,h
Example: +ESA: 0,0,0, ,0,0,255, for the defaults.
Reporting Supported Options
The modem reports the supported options in response to the following command:
Command: +ESA=?
Response: +ESA: (list of supported a values), (list of supported b values),
(list of supported c values), (list of supported d values),
(list of supported e values), (list of supported f values),
(list of supported g values), (list of supported h values)
Example: +ESA: (0),(0),(0-1), ,(0-1),(0),(255),
10.4.10 +ESR=n - Selective Repeat
This extended-format numeric parameter controls the use of the selective repeat (SREJ) option in
V.42.
Command: +ESR=[n] Decimal number 0 specifying that SREJ is not used.
Example: +ESR: (0) For default settings.