Northern UTA220/UTA220k manual CTS Pin Operation, DSR Pin Operation, Command Procedures, Commands

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,	Clarity characters
parenthesis, and period

UTA220/UTA220k 6-3