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Chapter 4 - V.22bis Commands
S16 - Test Mode Bit Mapped Options Status
S16 indicates the test in progress status. Default: 0
Bit 0 Local analog loopback. 0 = Disabled. (Default)
1 = Enabled. (&T1) Bit 1 Not used
Bit 2 Local digital loopback 0 = Disabled (default)
1 = Enabled (&T3)
Bit 3 Remote digital loopback (RDL) status 0 = Modem not in RDL
1 = RDL in progress Bit 4 RDL requested (AT&T6)
0 = RDL not requested (default)
1 = RDL requested (&T6) Bit 5 RDL with self test
0 = Disabled (default)
1 = Enabled (&T7)
Bit 6 Local analog loopback (LAL) with self test 0 = Disabled (default)
1 = Enable (&T8) Bit 7
S19 - Reserved
S19 is supported for backwards compatibility only. No value can be written. Responds with default value. Range: None
Default: 0
S20 - Reserved
S20 is supported for backwards compatibility only. No value can be written. Responds with default value. Range: None
Default: 0
S21 - V.24/General Bit Mapped Options Status
S21 indicates the status of command options. Default: 52 (34h) (00110100b)
Bits 0 - 1 Telephone Jack Control (&Jn). 0 = &J0 selected. (Default)
1 = &J1 selected.
2 = &J2 selected.
3 = &J3 selected.
Bit 2 CTS behavior (&Rn).
0 = CTS tracks RTS (&R0).
1 = CTS always on (&R1). (Default) Bits
0 = &D0 selected.
1 = &D1 selected
2 = &D2 selected. (Default)
3 = &D3 selected.
Bit 5 RLSD behavior (&Cn). 0 = &C0 selected.
1 = &C1 selected. (Default) Bit 6 DSR behavior (&Sn).
0 = &S0 selected. (Default)
1 = &S1 selected.
Bit 7 Long space disconnect (Yn). 0 = Y0. (Default)
1 = Y1.
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