User's Manual

108
Modem 34336
DTR D IALING IN V.25 BIS M ODE
An alternative to using the V.25bis CRS command to dial a stored number is
to use the DTR dialing option. With DTR dialing enabled, the autodialer will
dial the number stored in the phone cell displayed in the front-panel AUTO-
DIAL screen when DTR goes high for at least 50 ms.
To enable V.25 bis DTR dialing, sue the Summary Setup feature (see
Appendix C) to change the parameter for V25 bis DTR dialing to 1. Do not
select DTR dialing via the front panel DIALER screen; this will not enable
DTR dialing for V.25 bis mode. V.25 bis DTR dialing will function only if
the V25bis DTR dialing parameter is enabled (set to 1) and the V.25 bis
autodialer is enabled.
6.2 V.25 bis Autodialer Commands
In asynchronous applications, V.25 bis commands are issued directly from
the DTE keyboard or through communications software. In synchronous
applications, the V.25 bis commands are used to facilitate computer-
controlled communications.
Punctuation and spaces may be used with V.25 bis commands for clarity,
but they are not required. If used, they are ignored by the modem. One
exception is the colon ( : ), which instructs the autodialer to wait for a
dial tone.
The V.25 bis commands are described below and are summarized
in Table 6-1. See Table 6-3 for explanation of the codes displayed
in response to commands.
• CIC — Connect Incoming Call. The CIC command instructs the
autodialer to answer incoming calls. The effect is the same as enabling
auto-answer on the modem’s front panel.
• CRN — Call Request, Number Provided (Syntax: CRN 5557979). By
using the CRN command, you can dial a number directly from the DTE
keyboard. Numbers from 0 through 9 can be dialed, and if tone dialing
is enabled, the characters A, B, C, D, #, and * can also be dialed.
The dialing parameters listed in Table 6-2 are used with the CRN
command to specify how or when a number should be dialed. For
example, the command line CRN :T3331234 instructs the autodialer
to wait for a dial tone (:) and then tone-dial (T) the number 333-1234.
• CRS — Call Request, Address Provided (Syntax: CRS 2). The CRS
command allows you to dial a number simply by specifying its memory
address. In the example given above, the autodialer dials the number
stored in memory address 2. Store the number at the specified address
using the PRN command (Table 6-1).