Table of Contents
Advertisement
12. Connecting Peripherals, Hosts, and
Modems to the LIU
The LAN Interface Unit (LIU) is equipped with ports for connection to external
devices such as ASCII terminals, printers, host computers, and modems. The basic
LIU is equipped with two 25-pin RS-232-C ports and one parallel Centronics-type
port.
Optional kits are available as follows:
•
•
•
This procedure assumes the LIU has already been installed according to Part 11.
When connecting the external devices to the LIUs, refer to the floor plan and the
provisioning tables in the Site Records, 450-1011-152, for equipment layout and
cabling information.
The LIU RS-232-C ports are configured as data terminal equipment (DTE) and
therefore require a null modem cable (or modem eliminator) to be connected
directly to other data terminal equipment (such as ASCII terminals, printers, and
host computers). If modems are used, the null modem cable is not required.
The Line Card Option (LCO) Board, has an additional eight 9-pin RS-232-C
ports.
The Mag Tape Option Board, has an additional two parallel Centronics-type
ports. The SASI version of the Nine-track Magnetic Tape Unit connects to port
04 on this board. (The SCSI version of the unit connects directly to the SCSI
bus.)
The Alarm Interface Unit (ALIU) monitors the status of the system and
provides visual and audible alarms. (See Part 15 for installation instructions.)
Note: Data communications involving RS-232-C devices use a cabling
convention whereby DTE devices must be connected directly to data circuit-
terminating equipment (DCE) devices. The null modem cable interchanges two
wires so that the LIU appears to the DTE as data circuit-terminating equipment
(DCE). Modems, being DCE, can connect directly to the LIU.
103
Practice 450-1011-201
Advertisement
Table of Contents
