Telebit T3000 Reference Manual page 119

S47 DSR/DCD Delay Time
Range: 0-255
Default: 4 (200 milliseconds)
See also: &S, &C
The S47 register specifies the amount of time that
DSR and/or DCD is pulsed when carrier is lost and
&S2 or &C2 is in effect. Each count represents 50
milliseconds.
S48 Control Character Mask
Range: 0 or 1
Default: 0
The S48 register controls how the modem determines
if a character sent by the local DIB is an XON,
XOFF, or ESCAPE character. Possible contents for
this register are as follows:
O The most significant bit of the 8-bit character
received is set to O before comparing it with the
value in the S2, S56, and S57 registers to
determine if the character is an ESCAPE, XON, or
XOFF character, respectively. As a result, if S2,
S56, or S57 is set to a decimal value greater than
127, the modem disables recognition of the
character specified by the register.
1 All eight bits are compared with the value in the
S2, S56, or S57 registers to determine if the
character is an ESCAPE, XON, or XOFF
character. Use this register setting only when the
local DTE is using eight data bits with or without
parity.
Note:
If the local DIB is using a data format of seven data
bits plus parity, set the S48 register to 0 to mask the
eighth bit when testing for ESCAPE, XON, or
XOFF. This permits end-to-end parity checking
between data, and allows the modem to recognize
ESCAPE, XON, and XOFF.
6-12 AT Register Descriptions