User`s guide

S27 0 Bit-mapped register setup. To set the register, see

instructions for S13.

Bit Value Result

0 1 Enables ITU-T V.21

modulation at 300 bps for overseas calls; in V.21

mode, the modem answers both overseas

and domestic (U.S. and Canada) calls, but

only originates V.21 calls. (Default Bell 103)

1 2 Enables unencoded (non-

trellis coded) modulation in V.32 mode; rarely used part

of ITU-T Recommendation V.32.

2 4 Disables V.32 modulation.

3 8 Disables 2100 Hz answer

tone to allow two V.42 modems to connect

more quickly.

4 16 Enables V.23 fallback mode.

5 32 Disables V.32 bis mode.

6 64 Reserved.

7 128 Software compatibility mode.

This setting disables the codes and displays the 9600

code instead. The actual rate of the call can be

viewed on the ATI6 screen. Used for

unusual software incompatibilities. Some

software may not accept 7200, 12.000 and

14.400 bps or greater result codes.