Toshiba TECRA M4 User Manual page 246

S-registers
S1 Ring counter
S2 AT escape character (user defined)
S3 Command line termination character (user defined)
S4 Response formatting character (user defined)
D-2
This register is read only. The value of S1 is incremented with
each ring. If no ring occurs over a six-second interval, this register
is cleared.
Range: 0-225
Default: 0
Units: rings
This register determines the ASCII values used for an escape
sequence. The default is the + character. The escape sequence
allows the modem to exit data mode and enter command mode
when on-line. Values greater than 127 disable the escape
sequence.
Range: 0-255, ASCII decimal
Default: 43
Units: ASCII
This register determines the ASCII values as the carriage return
character. This character is used to end command lines and result
codes.
Range: 0-127, ASCII decimal
Default: 13 (carriage return)
Units: ASCII
This register determines the ASCII value used as the line feed
character. The modem uses a line feed character in command
mode when it responds to the computer.
Range: 0-127, ASCII decimal
Default: 10 (line feed)
Units: ASCII
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