Echelon LNS - Manual (Page 90)

LNS Programmer's Guide 76
scenarios. For example, you could begin defining a network’s devices and connections
using the engineered system scenario. Once the network is commissioned, you could add
additional devices to it using the ad hoc scenario.
Engineered Mode Installation
In the engineered mode installation, installation is a two-step process consisting of a
definition phase and a commissioning phase. In the definition phase, the application
defines all of the network configuration information in the LNS database, without
modifying the physical network. In the commissioning phase, the application loads the
configuration information defined during the definition stage into the physical network.
The advantage of the engineered mode installation scenario is that the network
installation on-site is quick, easy, and error free, since most of the time-consuming data
entry and processing is done off-site. This scenario is often used when installing systems
that require preplanning, when building multiple clones of a single network design, or
when installing systems that are built in response to a bid.
For more information on engineered mode installation, see Engineered Mode on page 77.
Ad Hoc Installation
In the ad hoc installation scenario, installation is a one-step process. In this scenario, a
network tool loads the network configuration information into each device as the devices
are physically installed on the network, and then creates connections between them. The
LNS application provides a user interface that controls the amount of information and
the sequencing of the information required.
This is different from the engineered system scenario in that information is loaded
incrementally. It is different from the automatic installation scenario in that the installer
makes decisions about the network configuration instead of the tool (although the tool
may provide assistance). The goal of ad hoc installation is to integrate all installation
activities into a single step. Ad hoc installation offers the most flexibility, since it allows
the installer to make decisions on-site. Since this scenario can be time consuming, it is
typically used in conjunction with the engineered system scenario for large installations.
Ad hoc is the installation scenario typically used when servicing an existing network.
Automatic Installation
Automatic installation is usually accomplished by an onsite network tool with a minimal
user interface. The network tool automates all installation tasks, so it must discover
when new devices have been attached to the network, and form network variable and
message tag connections between the discovered devices in a way that makes sense in
the context of the network design. The network tool must also be able to determine when
devices have been removed from the network, and reconfigure the network accordingly.
To be able to automate installation and eliminate or minimize end-user interaction, the
network tool’s application program needs to be very knowledgeable about the system it is
managing. For this reason, automatic installation is most commonly used in single
vendor systems, or in systems that are dedicated to a single function.
For more information on automatic installation, see Automatic Installation on page 89.