User's Manual

32
Modem 34336
The default settings for each option are listed in Appendix B.
The Quick Setup options (one for each operating mode) affect the entire
modem configuration. See Chapter 2.
The Line Type options are available for all modes:
• 2-WIRE DIAL — for dialup applications.
• 2W-LL — for leased-line applications using 2-wire lines.
• 4W-LL — for leased-line applications using 4-wire lines.
The Speed Limit option (available for all modes) allows you to set a minimum
and/or maximum data rate. The Modem automatically operates at the
highest possible data rate within the limits selected, as indicated in Table 3-1.
Only the minimum rate selection applies to Hayes mode operation.
EIA-23 is available for setting the maximum rate only. If EIA-23 is selected,
the rate is set at either 9600 or 4800 bps, depending on the condition of
pin 23 on the EIA interface:
• Pin 23 high (greater than or equal to +3 volts) = 9600 bps.
• Pin 23 low (less than or equal to -3 volts) = 4800 bps.
Use the Speed Matching option if you don’t want speed conversion. You can
set the DTE interface rate to follow the rate at which the modem connected
(i.e., DTE=DCE).
NOTE
Speed matching is only effective for dial applications and will
only function if V.42 error correction and/or buffer mode is enabled.
To select speed matching, refer to Appendix C. Follow the instructions given
there to change the value identified in the MISCELLANEOUS OPTIONS
diagram as the DTE=DCE speed parameter from 0 (the factory setting) to 1.
The Speed Limit Type screen is only present on the Modem . The V.32
master handshake normally used by the Modem is incompatible with the
CCITT V.33 and Bell 208 handshakes. However, the Modem can be
configured for either V.33 or Bell 208 compatibility.
V.33 or Bell 208 speed limits can be set independently of other options via
the Speed Limit Type screen. However, to ensure proper operation, it is
recommended that you use the V.33 or 208 Quick Setup configuration,
as explained in Chapter 2.