Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

34 Chapter1

Introduction

ASC Software Overview

Conﬁguration with OpenView DTC Manager

Effective with version A.30.00 of MPE/iX, HP 3000 Series 900 and

HP 9000 Series 800 computers may be part of a network managed by

the OpenView DTC Manager. Devices connected to the DTCs on such a

network are conﬁgured through a PC-based network management

workstation which is also attached to the LAN, and the DTC control

software is subsequently downloaded from the PC.

The connection between each host computer and the LAN is conﬁgured

using NMMGR, along with proﬁles of the asynchronous device types

that will be accepted for connection to the host, and the ldev numbers of

devices that require a permanently associated (nailed) connection.

However, many of the other parameters usually associated with a

connection between a host system and each individual asynchronous

device no longer need to be conﬁgured through NMMGR.

Nailed and Non-Nailed Connections

Asynchronous devices attached to DTCs managed by an OpenView

workstation can be conﬁgured as either nailed or non-nailed devices on

the MPE/iX host systems to which they have access.

A nailed device is one that is permanently associated with an ldev

number through the NMMGR conﬁguration of an MPE/iX system. Any

time a connection exists between a system and one of its nailed devices

the same ldev number will belong to that device. Since only nailed

devices can be accessed programmatically, all printers must be nailed,

as must any devices that will be accessed as programmatic devices at

any time.

A non-nailed device is a device that is able to establish a connection to

an MPE/iX host system but has no permanently assigned ldev number

in the NMMGR conﬁguration ﬁle of that system. The user of a terminal

connected as a non-nailed device can establish a session provided a

connection is available and the MPE/iX host conﬁguration speciﬁes a

device proﬁle matching the characteristics of the device requesting the

connection. When the user logs on to the system, an ldev number is

assigned from a pool of available ldev numbers deﬁned through the host

system’s NMMGR conﬁguration.

When the connection is ended (the user logs off) the associated ldev

number is returned to the pool of ldev numbers and becomes available

for use by a different device connection.

The use of non-nailed device connections provides several major

advantages. Non-nailed connections simplify the conﬁguration process

that must be done on each MPE/iX system, since conﬁguration values

do not have to be entered separately. It is possible, if you specify a

sufﬁcient number of non-nailed connections on each host, for you to add