Echelon OpenLNS Commissioning Tool - Manual (Page 42)

26 Getting Started
Design Overview
To prepare to design an OpenLNS CT network, follow these steps:
1. Define network requirements and organization.
2. Select a network installation scenario.
3. Determine user permissions for viewing and changing the network.
4. Optimize network performance.
Defining Network Requirements and Organization
You can define your network’s requirements by evaluating which devices (sensors, actuators, and
controllers) are needed to achieve the desired network functions and how the devices will be integrated
into the network. For example, your network may need a simple fan coil unit, which could require a
fan start/stop relay, a cooling coil valve, and a supply air temperature sensor. You could use digital
output, analog output, and analog input devices, respectively, to integrate these devices (the analog
output module could also includes a PID controller you can use to control the fan coil unit).
Once you define the network requirements, you can figure out how to organize the network in
OpenLNS CT. You can help organize the network by answering the following questions:
• How will devices and functional blocks be grouped within subsystems?
• Which functional blocks are needed for the devices to accomplish desired tasks?
• How do functional blocks need to be configured and connected to correctly interpret values from
sensors, perform any necessary calculations, and drive actuators?
Selecting a Network Installation Scenario
You can design your entire network without commissioning any devices until after your design is
complete, or you can design your network and commission devices at the same time. These two
approaches are called installation scenarios. The first network installation scenario is called the
engineered system and the second is the ad-hoc system. You can use both scenarios within a single
system, or you can use either exclusively. The best scenario for a given network depends on many
factors including the skill level of the installer, desired flexibility for the network, and the end-user
requirements.
Engineered System Scenario
The engineered system scenario allows you to design the network without having access to the
physical devices
First, you design the network offsite using OpenLNS CT. You drag OpenLNS CT SmartShapes
representing devices, routers, IP-852 routers, functional blocks, and connections from an OpenLNS
CT stencil to an OpenLNS CT drawing and arrange them on the drawing, and into multiple subsystems
if desired.
Once you are onsite and have attached an OpenLNS CT computer to the network, you then
commission the physical devices. OpenLNS CT commissions a device by configuring the physical
device to match the configuration that you specified in the OpenLNS CT drawing.
Engineered systems must often be modified during on-site installation due to differences between
as-drawn plans and the physical network. OpenLNS CT supports on-site changes to the engineered
system to allow for these changes during commissioning.
The advantage of the engineered system scenario is that it makes network installation quick, easy, and
error-free because most of the time-consuming data entry and processing is done offsite during the
design phase. This scenario is often used for building and industrial automation systems, in which the
original design closely matches the actual installation.