Identifying System Connections

To identify the distributed terminal controller (DTC) connections

The DTC is used to control serial devices such as terminals, modems, and serial printers on a local area network (LAN). The DTC is supported on Series 917 through Series 937 systems, Series 925 through Series 949 systems, Series 958 systems, Series 947 through Series 967 systems, and Series 950 through Series 980 systems.

A user who accesses a system remotely has a choice of either a console connection or a session through the DTC. All RS 232C and RS 422 devices, except the system console, must go through the DTC to be connected to the SPU. The RS 232C (a 3-pin connector) connects serial devices (terminals, PCs, printers) to the SPU using modem or direct connections up to 50 feet away from the DTC. The RS 422 (a 5-pin connector) directly connects serial devices to the SPU up to 4000 feet away from the DTC. The DTC connects terminals for general use to a LAN. Figure 12-11 “Rear View of DTC” shows the rear view of the DTC and where the different connections reside.

Figure 12-11 Rear View of DTC

The SPU must have one LANIC card installed and dedicated to DTC connections. The DTCs use thin or thick LAN cables.

The DTC terminals are configured for each system using the NMMGR program. Refer to Configuring Systems for Terminals, Printers, and Other Serial Devices (32022-90001) for a description of using the NMMGR program.

To identify network connections

Networks are used to communicate between terminals and systems (DTC), between systems and systems (NS), and between systems and IBM mainframes (PSI) and remote NS. They are supported on the Series 917 through Series 937 systems, Series 925 through Series 949 systems, Series 958 systems, Series 947 through Series 967 systems, and Series 950 through Series 980 systems. The NMMGR program, described in Configuring Systems for Terminals, Printers, and Other Serial Devices (32022-90001), configures the network devices; then the following systems can be accessed:

Figure 12-12 “Network Connections” illustrates the various network connections that are available. The LANIC (DTC) and LANIC (NS) can be on the same LAN or on different LANs.

Figure 12-12 Network Connections

To identify system console connections

The system console is connected through the RS 232C junction frame="all", while all other terminals are connected through the DTC. As the system manager you designate its use to send and receive system messages.

The system console can be either local or remote. The local console is used for routinely entering and receiving system messages. The remote console is normally used by Hewlett-Packard support personnel to service the system. Remote system access is available as a remote console connection or as a session through the DTC. Any DTC terminal can be designated as the logical console by the system operator. The system operator can transfer the system console capabilities to any terminal on the LAN. An example of system console connections is provided in Figure 12-13 “System Console Connections”. Definitions of the terms are provided in Table 12-5 “Definitions of System Console Connections”.

Figure 12-13 System Console Connections

To recognize local/remote console capabilities

The local and remote system consoles are used for normal system communication by HP support personnel. Each needs to be connected to the RS 232C junction frame="all". They have CTRL A and CTRL B command access capabilities. Table 12-6 “Control A and B Commands” describes each command:

The remote system console is used by Hewlett-Packard support personnel to service the system.

The remote system console must be enabled by a key switch and a command from the system console before use. When it is enabled and in use, the commands and messages display on both the local and remote console screens. Only one keyboard is active, however, and the BREAK key on the inactive keyboard activates that keyboard and disables the other.

To identify the logical system console

The logical system console can be any distributed terminal controller (DTC) terminal. System console capabilities are moved to a DTC terminal by using the CO command. A logical system console does not support CTRL A and CTRL B commands.