Troubleshooting Terminal, Printer and Serial Device Connections - Edition 4 (32022-90030)

16 Chapter 1
General Information
Datacommunications and Terminal Subsystem (DTS)
The DTC is controlled by software that is downloaded by its host
system at boot time or by the OpenView Windows Workstation,
depending on the type of management used. Systems can use either
host-based management or PC-based management. Refer to
Configuring Systems for Terminals, Printers and Other Serial Devices
for more information on host-based management and PC-based
management.
The downloaded software includes DTC operating code and
configuration information. Once the software is downloaded, the DTC is
ready for operation. Devices physically connected to its ports and
properly configured can establish communications links with the host
computer.
You can troubleshoot connections with TermDSM only on systems that
use host-based management. Troubleshooting for PC-based
management is covered in Using HP OpenView DTC Manager.
LAN Interface Card (LANIC)
Every computer in the HP 3000 Series 900 family has a LAN Interface
Card (LANIC) as part of its hardware. This card is located in the
System Processing Unit (SPU) and enables the system to communicate
with asynchronous devices via the LAN by providing the basic
connection between the computer and the LAN.
Datacommunications and Terminal Controllers are connected to the
system by a Local Area Network (LAN), over coaxial cable which
conforms to the IEEE 802.3 standard. Hewlett-Packard provides two
versions of this cable, ThinLAN and ThickLAN, each provides certain
specific advantages to the user.
Each DTC has a unique LAN address which is made known to the
system during configuration. Also referred to as the node address or the
station address, it serves to identify the DTC as a node on the LAN.
Keep in mind, however, that while DTCs are treated as nodes for the
purpose of configuration, they are not true nodes. DTCs are dedicated
communication devices; they are not self-contained, general-purpose
computer systems.
ThinLAN Connection
LAN cable is available in two versions. The first, ThinLAN (Type 10
BASE 2), is available in connection lengths of up to 185 meters
(555 feet), and provides an economical solution where DTCs are located
in close proximity to their computer system.
ThinLAN is a flexible cable which is easy to install, and can be bent
around objects to accommodate its use in confined areas. ThinLAN is
connected to the computer through a ThinMau (Medium Attachment
Unit), with a small BNC T-connector used to connect each DTC to the