HP 3000 Manuals HP 3000 Manuals
DTC/3000 Terminal I/O Enhancements
by Mary Ann Little
Grenoble Networks Division-Cupertino
The Datacommunications and Terminal Controller (DTC/3000) is a LAN-based
controller for asynchronous access to HP 3000 and non-HP systems. It
also supports communication over X.25 networks as well as the Telnet
service for the HP 3000 Series 900 systems. For asynchronous access,
DTC/3000 provides connections to terminals, PCs in terminal emulation
mode, and serial printers.
In addition to product enhancements, modems that are capable of handling
data at 4800 and 9600 baud are certified with the MPE/iX Release 4.0.
MPE/iX Release 4.0 introduces the Terminal I/O enhancements listed below:
* DTC Related Enhancements
Multisession (requires DTC 10.5 or later)
Powerfail recovery of switched DTC ports
PAD Support Selectable Profiles
* Field Mode Enhancements
Interbyte Timer
Multiple AEOR (Alternate-End-Of-Record) Characters
Delete To Backspace Mapping
Escape Sequence Read Termination
Suppress Echo of Read Terminator
* System Related Enhancements
Higher baud rate modems
Support for 1700 asynchronous devices
Terminal Type File names for Host Based Management
DCC Error Message Numbering
Logging of DCC boot time messages
* Support Tool Enhancements
DTS/DTC Subsystem Validation Check
TIO MPE/iX Host Trace and Formatter
Enhancements to existing tools
DTC RELATED ENHANCEMENTS The following information describes the DTC
related enhancements included with this version of DTC/3000.
Multisession Multisession is the ability to have a device on a DTC
simultaneously associated with multiple sessions, jobs, or processes on
one or more hosts. Each port can support a maximum of 5 connections;
however, only one of the connections may be active at one time, the other
dormant connections are in a hold state. The connection establishment
method (LOGON or FOPEN) for multiple connections associated with a
particular port is determined by the first established connection. If
this is a LOGON then the other multisession connections to that port must
be LOGON. Similarly, if the first connection is established through the
use of an FOPEN, the other multisession connections must be established
through the use of an FOPEN.
Multisession is not supported on PAD terminals or connections through a
Telnet Access Card (TAC) or a Telnet Express Box (TEB). Multisession is
supported on switched ports only and some restrictions apply to nailed
devices. Listed below are the key points:
Switched Ports Multisession is supported for switched ports
only, so multisession is available only in a PC
based network environment. A terminal user may
log on to use CONTROLK to get to the DTC User
Interface, then issue a CONNECT command to
establish a new session to the same system or
to another system. If a user is running an
application and wants to establish multiple
sessions, the user must exit the application
before accessing the DTC User Interface.
Non-Switched Ports Multisession is not available on non-switched
ports because it is necessary to get to the DTC
User Interface in order to establish another
connection, and the DTC User Interface is not
accessible from non-switched ports.
Nailed LDEV If a switched port is configured as a nailed
LDEV on a system, multiple sessions from that
port to that system are not possible because
the port can have only the one connection
associated with the assigned LDEV on the host
system. Although multiple sessions to that
particular host are not possible, it is
possible to establish multiple sessions from
that switched port to other systems.
Non-Nailed LDEV If a switched port is configured as a
non-nailed LDEV on a system, multiple sessions
from that port to that system are supported in
addition to multiple sessions to different
systems.
Powerfail Recovery For Switched Ports With Release 4.0, recovery from a
DTC powerfail is supported for both nailed and non-nailed ports with the
ability to recover multiple sessions. As in prior releases, printer
connections, and sessions using a PAD terminal, Telnet Access Card (TAC),
Telnet Express Box (TEB) or a modem are not recovered.
The DTC sends a multicast message to inform all XL hosts that powerfail
recovery must be done on all connections associated with that DTC. This
multicast message is sent out three times. After the third multicast
message, the DTC only accepts powerfail connection requests for a period
of 10 seconds. This prevents non-powerfail connection requests, (new
connection requests), from arriving before the powerfail recovery has
completed. The result of accepting only powerfail requests during the 10
second period is that the DTC does not respond to a user typing RETURN
during this period.
PAD Support Selectable Profiles Selectable PAD Support Profiles are now
supported in a Host Based network management environment. This
enhancement, which is also available for the PC Based network management
environment with DTC 12.0, allows for the configuration of certain PAD
parameters that were previously limited to default values. Similar to
direct connect and modem connect profiles, the type, record width, logon
(terminal) and spooling (printer) characteristics can be configured in
addition, PAD Support Profiles allow the configuration of:
* PAD Test Requested
* Send Initial Profile
* X.3 Setting Requested
* Data Forwarding Parm #4
FIELD MODE ENHANCEMENTS The terminal I/O (TIO) subsystem of the HP 3000
was originally designed for block-mode operation, which offers high
performance. Block-mode applications do not recognize application hot
keys. Examples are the cursor keys, Home, End, PgUp, PgDn, Ins and Del
keys, and perhaps certain control keys. To provide this functionality
without using character mode, which results in low performance, Field
Mode was created. Field Mode allows the DTC to collect normal user data
input without having to interrupt the CPU for each character, yet still
have many ways to return control to the application when the user enters
command input.
If a host system supporting this functionality is connected to a DTC
running an older version of software that does not support the
functionality, the intrinsic calls return a file system error (FSERR 68)
to the application.
For details on programming and intrinsic syntax, refer to the
Asynchronous Serial Communications Programmer's Reference Manual
(32022-61001) for programming details.
The Field Mode Enhancements are not supported for connections through:
* HP Network Services/3000 Virtual Terminal (VT) service
* PAD (Packet Assembler/Disassembler) terminals
* Telnet Access Card (TAC) or Telnet Express Box (TEB)
The following paragraph describes the Field Mode Enhancements.
Interbyte Timer The Interbyte Timer provides a new mechanism by which the
DTC can terminate a read and forward data to the host. It is most useful
for collecting data where there is no guarantee that an end-of-record
(EOR), or alternate-end-of record (AEOR) character is received, or that a
specified number of bytes is received. An example of such an environment
is the use of some types of bar code readers. An application program
accepting data from a bar code reader would use the Interbyte Timer to
complete the read because the bar code reader does not send terminating
characters.
Multiple AEOR Characters The multiple AEOR functionality allows an
application or user to specify a maximum of 16 AEOR characters. When the
list of AEOR characters is received, the DTC monitors input for those
characters. When the DTC receives one of the characters, it completes
the current pending read request with the received AEOR character as the
last byte of data.
The SPECIAL CHARACTERS screen in TTUTIL allows 16 TYPE 2 End-Of-Record
characters. Prior to Release 4.0, the field only accepted one character.
Errors are reported if the string of characters is not in the correct
format, or if more than 16 characters are entered. There is no default
value for this field.
Delete to Backspace Mapping The Delete to Backspace Mapping ("DEL as BS")
allows the Delete character (DEL) to be processed as a Backspace
character (BS). In order to support ANSI mode terminals, this
functionality is introduced because these terminals send the delete
character when BACKSPACE is pressed.
Normal processing of DEL is to strip the character from input. When "DEL
as BS" is set, the DTC maps a received delete character to the backspace
character and then processes it as if a backspace was received. The DEL
character performs whatever action the BS character would perform; in
other words, if BS is set as an AEOR character, DEL will also work as an
AEOR character and will actually be read by the application as a BS
character.
Escape Sequence Read Termination The Escape (ESC) Sequence Read
Termination is another new read termination method for the DTC. This
method is similar to the Interbyte Timer except that the timer used in
the ESC Sequence Read Termination is not enabled during the entire read.
This functionality enables an application to have a read terminated by an
ESC sequence and receive the entire ESC sequence in the data.
Suppress Echo Of Read Terminator
The Suppress Echo Of Read Terminator functionality gives an application
the ability to determine whether or not to include the read terminators
with the data that is echoed back to the device. Once echo suppression
is enabled, no read terminating characters are echoed to the device until
echo suppression is disabled. If the ESC Sequence Read Termination is
also enabled, the escape sequence is not echoed.
SYSTEM RELATED ENHANCEMENTS The following information descibes the system
related enhancements included with this version of DTC/3000.
Support For 1700 Configured Devices The number of asynchronous devices
that can be configured has increased from 850 in XL Release 3.0 to 1700
in MPE/iX Release 4.0. The largest valid LDEV number is now 2175.
Configuration errors caused by exceeding the limit are reported through
DTS/LINK Validation within NMMGR. The error, Too many LDEVs are being
used (must be <= 1700). DTSERR = 13, is displayed on the console.
Note that the maximum number of configured devices includes all devices,
(for example, tape drives, disc drives, and so on) and is not limited to
terminal I/O deivces, (for example, terminals, printers, and so on).
For NMMGR screen information and configuration steps, refer to
Configuring Systems for Terminals, Printers, and Other Serial Devices
(32022-61000).
Terminal Type File Names For Host Based Management The NMMGR utility has
been enhanced to accept a terminal or printer type file name for both the
terminal and printer host based profile screens. In the printer and
terminal profile screens, there is an additional field that accepts a
printer type file name.
DCC Error Message Numbering Prior to MPE/iX Release 4.0, no DCC errors or
warnings during system boot up were associated with a specific error
number. The error or warning would only give a procedure and location
number. With MPE/iX Release 4.0, a unique number is associated with each
error/warning.
Logging Of DCC Boot Time Messages Troubleshooting DCC errors at system
boot up is also simplified because now the DCC errors are logged to a
file. This file is called LOGDCC.PUB.SYS. It contains all DCC boot-time
messages with the boot-up date and time. This file contains information
for the most recent system boot. The errors will continue to be
displayed on the console.
SUPPORT TOOL ENHANCEMENTS The following information describes the support
tool enhancements included with this version of DTC/3000.
DTS/DTC Subsystem Validation Check NMVALCHK is a program that allows an
operator to easily check if the DTS/DTC subsystem is validated in the
NMCONFIG file before rebooting the system. The program will simply check
and print whether the subsystem is validated or not. The current date
and time and various error messages will also be displayed. Note that
this tool does not check if cross-validation has been done. NMVALCHK
resides in the PUB.SYS group.
TIO MPE/iX Host Trace And Formatter The tool TERMTRC is introduced in
MPE/iX Release 4.0 to provide a method for th user to trace and format
TIO Manager messages. Those messages received by TLDM SPLDM, TSPDM (DM)
and FCM are traced. A maximum of ten LDEVs may be traced at one
time. It is not possible to initiate two traces on the same LDEV
simultaneously. TERMTRC resides in the DTS0000.TELESUP group.
Enhancements To Existing Tools Enhancements to the TRMFRM portion of the
DTCDF tool, TIO DAT Macros and the NMDUMP tool have been made to
accommodate the product enhancements described in this article. The user
interface of these tools has not changed.
INSTALLATION CONSIDERATIONS The following information describes the
special installation instructions required with this version of DTC/3000.
Host Upgrade The TIO product is part of MPE/iX FOS and no special
installation is required.
After the MPE/iX system has been updated with the 4.0 FOS tape, it is
necessary to use the conversion utility, NMMGRVER, to convert the
configuration file NMCONFIG.PUB.SYS to the MPE/iX 4.0 format. Run the
TTUTIL utility to make any terminal/printer type file changes and run
NMMGR to make any Datacomm configuration changes. Be sure to perform the
DTS validation before exiting NMMGR, and the SYSGEN cross validation
before rebooting the system. Reboot the system and reset the DTC(s) to
make the changes effective.
DTC Upgrade In either Host Based or PC Based network management, the
MPE/iX 4.0 functionality requires a DTC48 to have additional memory.
DTC48s with a date code less than 3110 must be upgraded with the DTC48
Upgrade Kit (HP23248A). DTC48s with a date code 3110 or later and DTC16s
do not require additional hardware.
HP OpenView DTC Mgr Releases In a PC-based network management
environment, using the HP OpenView DTC Manager release 12.0 along with
the MPE/iX Release 4.0 provides full 4.0 TIO functionality. Refer to the
OpenView DTC Manager documentation for details regarding the features and
requirements for this product.
It is possible to run MPE/iX 4.0 with earlier releases of the OpenView
DTC Manager. In this case, the user will not get the full 4.0
functionality. Instead, the user will get the TIO functionality
associated with the earlier release of the OpenView DTC Manager. The
Multisession functionality is the one exception to this rule.
Multisession is supported with an OpenView DTC Manager running DTC10.5.
In this case, it is recommended that all patches to the OpenView DTC
Manager be installed. Note that no other MPE/iX 4.0 functionality is
available in a PC Based network management environment when the OpenView
DTC Manager is running DTC 10.5
It is also possible to run the OpenView DTC Manager release 12.0 with
earlier versions of FOS. The resulting functionality is that of the
particular MPE/iX FOS version.
USER DOCUMENTATION The manuals listed below have been updated to include
MPE/iX Release 4.0 information:
* Configuring Systems For Terminals, Printers and Other Serial
Devices
(32022-61000)
* Troubleshooting Terminal, Printer, and Serial Device
Connections(32022-61002)
* Asynchronous Serial Communications Programmer's Reference Manual
(32022-61001)
SUMMARY MPE/iX Release 4.0 introduces a number of Terminal I/O
enhancements. Access to the system is improved through the support of
powerfail recovery, multiple sessions on switched ports, and an increase
from 850 asynchronous devices in XL Release 3.0 to 1700 asynchronous
devices.
Field Mode enhancements are seen programmatically through the
implementation of new programming intrinsics. The following lists the
new Field Mode enhancements:
* Interbyte Timer
* Multiple AEOR Characters
* Delete To Backspace Mapping
* Escape Sequence Read Termination
* Suppress Echo of Read Terminator
If a host system that supports Field Mode functionality is connected to a
DTC that is running an older version of software that does not support
this functionality, the intrinsic calls return an error to the
application.
Refer to the Asynchronous Serial Communications Programmer's Reference
Manual (32022-61001) for programming details.
In PC-based network management environments it is necessary to consider
the OpenView DTC Manager Release. To benefit from all the MPE/iX Release
4.0 enhancements discussed in this article, it is necessary to update the
OpenView DTC Manager Workstation to release 12.0.
In either PC Based or Host Based network management, the MPE/iX 4.0
functionality requires a DTC48 hardware upgrade for DTC48s with a date
code less than 3110.