AT&T System 85 manual Asynchronous Data Unit ADU, Switch

Asynchronous Data Unit (ADU)

Asynchronous Data Unit (ADU)

The Z3A ADU is a small DCE-type limited-distance modem that allows direct connection between RS-232 equipment and the system digital switch. Used in conjunction with the Data Line circuit pack (System 75, DEFINITY G1 and G2) or the EIA Port circuit pack (System 85), the ADU com- pletes the direct link between the system switch and EIA terminals, printers, and host computer ports. In these applications, DTE devices can access the switch without using a separate data module or modem. The ADU is installed at the device end of the EIA connection. ADUs can also be hard-wired in pairs with other ADUs to interface data terminals directly to a host com- puter. This application is typical when access to the host is not made through the system.

Features

Speed

Standard data rates from 0.3 to 19.2 kbps and non standard data rates below 1.8 kbps. The auto adjust option will automatically match the transmission speed to the attached RS-232.

Full-duplex

Asynchronous

Built-in protection against voltage surges.

Physical Description

Dimensions

Note: The following dimensions are approximate.

Width = 2-1/4 inches

Depth = 4-3/4 inches

Height = 1 inch

Switch

An optional Originate/Disconnect switch can be used with the Z3A1, Z3A2, and Z3A4 ADUs.

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