New Features for DTS/TIO Subsystem

by Wendy Cheng
Commercial Systems Division

Introduction

The Datacommunications and Terminal Subsystem (DTS) consists of host (HP 3000) based software and the DTC (Datacommunications and Terminal Controller) terminal server.

The DTC family of products supports X.25 communication and Telnet access to HP 3000 systems, and TCP/IP communication to HP 9000 and non-HP systems.

The DTS allows terminal, PCs in terminal emulation mode, serial printer, and other asynchronous devices to communicate with LAN-based hosts in HP-only and multivendor networking environments.

New Features

The DTS/TIO subsystem provides the following new functionality for MPE/iX 6.0 release:

Support of 400 DTCs.
Support of 2000 device classes
Configuration of the maximum number of sessions for a terminal switching port on the Host-based DTC management.
Configuration of the number of hosts sharing the printer for a printer switching port on the Host-based DTC management.

The following enhancements were made to MPE/iX release 6.0 for the DTS/TIO subsystem to provide support for all DTC port configuration parameters of DTC version 14.4 for Host-based DTC management. Prior to release 6.0, these features were only available on the OpenView DTC Manager in a PC-based management configuration.

These new features are as follows:

Three new modem types for attached device. The new modem types are US modem In Out, European modem In Out, and Five wires modem.
Two new data length/parity settings. The DTS/TIO software has been enhanced to support two new parity types. The two new parity types are 8 bits data length with even parity and 8 bits data length with odd parity.
Configuration to enable or disable flow control between the DTC and the attached device.
Configuration of the number of stop bits on Host-based DTC ports.
Specification of whether "Keep Alive" mechanism is to be activated on Host-based DTC ports to detect if connection is still there.
Specification of whether port configuration parameters- data length and parity- have to be forced when binary mode is selected.
Dynamic Configuration of new port configuration parameters.

With these DTS/TIO enhancements to MPE/iX 6.0, you can use NMMGR to configure all DTC port configuration functionality that is available in DTC download version 14.4 using Host-Based DTC management.

See the manual Configuring System for Terminals, Printers, and Other Serial Devices for detailed descriptions of these new features.

Support of 400 DTCs

Users can now configure up to 400 DTCs on the HP 3000 host at a time. This is up from the earlier limit of 120 DTCs in MPE/iX 5.5 release. Thus the number of DTCs that can be connected to a HP 3000 is significantly increased.

The maximum number of LDEVs supported on the HP3000 is still 4649. This means that if a high number of DTCs are configured then the DTCs can not have all ports configured as nailed ldevs. The total number of supported LDEVs can be spread over the configured DTCs in any way you want.

Support of 2000 device classes

A device class is a name that can be assigned to a single or a group of ldevs. This enables the user to refer to the ldev or the group of ldevs by a name. For example, the ldev associated with a tape driver is referred to as TAPE. Similarly, LP and DISK are the device classes for the system printer and disks respectively.

The number of device classes supported has been increased from 1000 to 2000. This enhancement increased the flexibility for those users that need many devices classes.

Three New Modem Types for Attached

To give more flexibility, support has been added for three new modem types: US modem In Out, European modem In Out, and Five wires modem. However, these new modem types will be supported for the new types of DTCs only: DTC 72MX, DTC 16iX, and DTC 16MX.

The complete list of supported modem types with MPE/iX 6.0 is:

US modem In Out
European modem In Out
Five wires modem
US modem
European modem
None (no modem)

Data Length/Parity List Support

With MPE/iX release 6.0, you can now use NMMGR to configure the two new parity types in the Host-based terminal, printer and host profiles. These two new parity types are: 8 bits data length with even parity and 8 bits data length with odd parity. These parity settings were added in order to provide support for serial devices that need to use these settings. Devices that would use these need to be able to send and receive binary data and also need to check parity.

These two new parity types are only supported for the newer DTCs: DTC 72MX, DTC 16iX, DTC 16MX and DTC 16RX. They are not supported for the DTC 48 or older DTCs. The full list of supported parity setting with MPE/iX release 6.0 is as given:

7 bit data length with even parity
7 bit data length with odd parity
7 bits data length with parity forced to 0.
7 bits data length with parity forced to 1.
8 bits data length with even parity.
8 bits data length with odd parity.
8 bits data length with none parity.

Number of stop bits

With MPE/iX release 6.0, you can now configure the number of stop bits to be used for asynchronous characters in the host_based terminal/printer profiles. The possible values are 1 or 2 stop bits. This new configuration field will be supported for the new types of DTCs only: DTC 72MX, DTC 16iX, and DTC 16MX.

Enable Flow Control

When TIO terminals, printers and host ports are created, one of the features that can be configured is a parameter that is sent to the port that determines the data flow control behavior between DTC port and connection device.

With MPE/iX release 6.0, you can now use NMMGR to configure a parameter in the Host-based TIO profiles to enable or disable flow control. If this feature is enabled in NMMGR for terminal/ printer, the data flow between the DTC port and the connection device is made with Xon/Xoff characters. If this feature is disabled, the XON/XOFF characters sent from device are not interpreted by DTC. This function is also known as "software handshake." This new feature can be supported on all DTCs except for DTC 16RX. Any value entered for this type will be ignored.

Enable Keep Alive

This new feature allows you to specify whether "keep alive" mechanism is to be activated. When there is no data transfer between the DTC and the system, then a mechanism called "keep alive" is activated to detect if the connection is still there. This new feature is only applicable to the telnet/TCP connections. It is only available for switching screens for terminal, printer and host profiles.

If this configuration is enabled, the "keep alive" mechanism is to be activated to detect if a connection is still there when there is no data transfer between the DTC and the system. This new feature can be supported on all DTCs except DTC48 without the memory extension.

Save Port Config Binary

This new feature allows you to specify whether the port configuration parameters- data length and parity get forced when binary mode is selected. If set to YES, then the port configuration remains the same when binary mode is selected. If set to NO, then data length is 8 bits and parity is forced to none when binary mode is selected. This new feature is only applicable to telnet/TCP connections. This parameter is accessed from the terminal and printer profile switching configuration screen and the host profile screen.

This new feature can apply only to the new DTCs — DTC 72MX, DTC 16MX and DTC 16iX.

Specify the Maximum Number of Sessions for a Switching Port

Host-based terminal switching allows you to connect to other systems on the LAN from a terminal connected to a DTC that is using host-based management. In previous releases, each port on the DTC was restricted to one connection per port. Connections from PAD ports are still restricted to the system that is managing the DTC. To connect to these systems, you needed to log off or close the connection before connecting to an other system.

With MPE/iX release 6.0, you can now use NMMGR to configure each DTC port to allow up to 5 connections at the same timer. If connections are to HP3000 systems using Host-based management, then only one connection is allowed to each system. This is because each system must configure the DTC port on a specific LDEV (nailed devices). if the connections are to HP3000 systems using PC-based management, then more than one connections is allowed. This is because it is allowed to configure the DTC port to use non-nailed LDEVs. If the DTC port on the PC-based system is configured as nailed, then only one connection is allowed to that system.

This feature is configured on the terminal profile switching configuration screen. The maximum number of connections is five and the default is one.

Number Of Hosts Sharing Printer

Host-based printer switching allows the serial printer connected to a DTC port to be shared by more than one HP 3000 host. You can now use NMMGR to configure the DTC port to allow a printer to be shared by up to 5 hosts. This feature is configured on the printer profile switching configuration screen. The maximum number of systems that can share at one time is 5 and default is 1. Thus the number of HP 3000 hosts that can share a printer is increased.

Dynamic Configuration of New Port Fields

Dynamic Configuration provides the capability to perform DTS/TIO configuration tasks without the need to shutdown the HP 3000 system. With MPE/iX release 6.0, you can now change the following new fields in a terminal, printer or host profile dynamically:

Change "Data Length/Parity list" field in a terminal or printer profile.
Change "Number of Stop bits" field in a terminal or printer profile.
Change "Enable Flow Control" field in a terminal or printer profile.
Change "Enable Keep Alive" field in the profile for a switching port.
Change "Maximum Number Of Sessions" field in the terminal profile for a switching port.
Change "Number of Hosts Sharing Printer" field in the printer profile for a switching port.
Change "Save Port Config in Binary" field in the terminal and printer profile for a switching port.

You can now make dynamic configuration changes of these new fields by using NMMGR to modify the configuration file NMCONFIG.PUB.SYS, then invoking the command DTCCNTRL. DTCCNTRL can be invoked by NMMGR after DTS validation has successfully completed, or later by you from the CI prompt.