AT Commands and S-Registers
B-20
Issue 1 April 1994
Table B-1. AT Command and S-Register List (19 of 34)
AT
Command/
S-Register
Description
X
n
Extended Result Codes, Dial Tone Detect, Busy
Tone Detect
See Table A-2 in Appendix A for a list of extended
result codes.
X0
Disables extended result codes 5–16, dial
tone detect, and busy tone detect
X1
Enables extended result codes 5–16,
disables dial tone detect and busy tone
detect.
X2
Enables extended result codes 5–16 and
dial tone detect, disables busy tone detect.
X3
Enables extended result codes 5–16,
disables dial tone detect, enables busy
tone detect.
X4
Enables extended result codes 5–16,
dial tone detect, and busy tone detect.
X5
Adds error control suffix (REL) to extended
result codes 20–27 if error control is used,
enables dial tone detect and busy tone
detect.
X6
Adds either V.42 or MNP suffix to
extended result codes 20–27 if data
compression is used, enabled dial tone
detect and busy tone detect.
X7
Computer’s data rate appears in the
Connect message instead of the telephone
line data rate, enables dial tone detect and
busy tone detect.