Northern UTA220/UTA220k - Manual (Page 57)

UTA220/UTA220k
6-3
V.25 bis Dialer Operation
CTS Pin Operation
The UTA220 asserts the CTS pin when DTR is high (CTS
follows DTR), except that CTS goes low during the connect
sequence.
DSR Pin Operation
The UTA220 holds the DSR pin low until a connection is
established.
COMMAND PROCEDURES
When the UTA220 is in V.25 bis command mode, it awaits the
receipt of a V.25 bis command from the DTE. Each command
must be contained in a separate frame. The UTA220 also sends
indications to the DTE to advise it of call status.
Commands may be upper or lower case. Responses and
indications from the UTA220 are always uppercase.
Commands cannot contain leading or embedded spaces or
other characters, but some commands allow clarity characters
in the parameter string that follows the command.
Each command message consists of a three octet command
code and a 0 to 60 octet parameter field (depending on the
command). The UTA220 parses the command, returns a
response message, and then executes the command.
COMMANDS
Commands are messages sent by the DTE to the UTA220 to
cause it to perform a given operation. The commands are listed
on the following pages.
Dial Command: CRN xx..x
The CRN (Dial) command contains a parameter field of one
to 40 characters (excluding clarity characters) specifying the
number to dial and any dial modifiers. Clarity characters,
which are ignored by the UTA220, consist of spaces, dashes,
parenthesis, and periods. Valid dial characters and modifiers
are shown in Table 6-1.
Table 6-1: V.25 bis Dial Parameters
Character Function
0-9 Dial digits
* and # Dial digits
Space, dash,
parenthesis, and period
Clarity characters