Telenetics 56 User Manual
Page 99
AT Commands
Page 91
Synchronous Access Mode Commands
Three commands support Synchronous Access Mode:
+ES
Enables and disables Synchronous Access Mode in the client or central
site modem (see 0)
+ESA
Configures the operation of the Synchronous Access Submode
+ITF
Selects Transmit Flow Control Thresholds
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 DCE Control
and Synchronous Data Modes for Asynchronous DTE).
+ESA - Configure Synchronous Access Submode
The operation of the Synchronous Access sub-Mode is configured by the +ESA
parameter.
This extended-format compound parameter is used to control the manner of operation of
the Synchronous Access Mode in the modem. It accepts six numeric subparameters:
Syntax
+ESA=[
Defined Value
data buffer underrun condition occurs, while operating in Transparent
sub-Mode. The options are:
0 In Transparent sub-Mode, modem transmits 8-bit SYN
sequence on idle. Modem receiver does not hunt for
synchronization sequence (default and fixed).
data buffer underrun condition occurs immediately after a flag, while
operating in Framed sub-Mode. The options are:
0 In Framed sub-Mode, modem transmits HDLC flags on idle
(default and fixed).
> Specifies the actions undertaken by the modem when a transmit data 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. procedures besides those specified in § 12/V.34 shall be performed by the CRC polynomial used while operating in Framed sub-Mode.
buffer underrun or overrun condition occurs immediately after a non-flag
octet, while operating in Framed sub-Mode.
the modem when switching from primary channel to secondary channel
operation, and vice versa. This subparameter should not be commanded.