Synchronous Access Mode Commands; Esa - Configure Synchronous Access Mode - Conexant H08-15355F Reference Manual

3.2.8 Synchronous Access Mode Commands

3.2.8.1 +ESA - Configure Synchronous Access Mode

This extended-format compound parameter controls the manner of operation of the Synchronous Access Mode in the
modem.
Enabling Synchronous Access Mode enables the use of the 8-bit command characters defined in Table 9/V.80 of the Draft
ITU-T Recommendation V.80 (DATA COMMUNICATION OVER THE TELEPHONE NETWORK; In-Band modem Control and
Synchronous Data Modes for Asynchronous DTE).
Syntax
+ESA=[<trans_idle>[,<framed_idle>[,<framed_un_ov>[,<hd_auto>[,<crc_type>[,<nrzi_en>[,<syn1>[,<syn2>]]]]]]]]
Defined Values
<trans_idle> Decimal number which specifies the bit sequence transmitted by the modem when a transmit data
buffer underrun condition occurs, while operating in Transparent sub-Mode. The options are:
<framed_idle> Decimal number which specifies the bit sequence transmitted by the modem when a transmit data
buffer underrun condition occurs immediately after a flag, while operating in Framed sub-Mode. The
options are:
<framed_un_ov> Decimal number which specifies the actions undertaken by the modem when a transmit data buffer
underrun or overrun condition occurs immediately after a non-flag octet, while operating in Framed
sub-Mode.
<hd_auto> Decimal number which specifies whether or not, in V.34 half-duplex operation, additional procedures
besides those specified in § 12/V.34 will be performed by the modem when switching from primary
channel to secondary channel operation, and vice versa. This subparameter should not be
commanded.
<crc_type> Decimal number which specifies the CRC polynomial used while operating in Framed sub-Mode. The
options are:
<nrzi_en> Decimal number which specifies if Non Return to Zero Inverted (NRZI) encoding is to be used by the
modem for transmit and receive data. The options are:
<syn1>, <syn2> Decimal number which specifies the octet value(s) to be used while performing character-oriented
framing. <syn1> is to be commanded to 255 (FFh); <syn2> is not to be commanded.
Reporting Current or Selected Values
Command: +ESA?
Response: +ESA: <trans_idle>,<framed_idle>,<framed_un_ov>,<hd_auto>,<crc_type>,<nrzi_en>,<syn1>,<syn2>
Example: +ESA: 0,0,0,,0,0,255,
1118
Command Reference Manual
0 In Transparent sub-Mode, modem transmits 8-bit SYN sequence on idle. Modem
receiver does not hunt for synchronization sequence (default and fixed).
0 In Framed sub-Mode, modem transmits HDLC flags on idle (default and fixed).
0 In Framed sub-Mode, modem transmits abort on underrun in middle of frame. (Default.)
1 In Framed sub-Mode, modem transmits a flag on underrun in middle of frame, and
notifies DTE of underrun or overrun.
0 CRC generation and checking disabled. (Default and fixed.)
0 NZRI encoding and decoding disabled (default and fixed).
For the defaults.
Conexant
3-39