Acuity Controls nLight ECLYPSE User Manual

Typical BACnet 24VAC-
Powered Controller
Data Bus Shield:
Isolate with
electrical tape
Data Bus Shields: Twist
together and Isolate
with electrical tape
Typical BACnet 24VAC-
Powered Controller
Typical BACnet 24VAC-
Powered Controller
Data Bus: Shielded Twisted Pair Cable
NET+ NET- NET+ NET- NET+ NET-
Typical BACnet 24VAC-
Powered Controller
NET+ NET-
Data Bus Shield:
Isolate with
electrical tape
Data Bus Shields:
Connect to the ‘S’
terminal
Electrical
System
Ground
The shield of the data bus must be connected to
the electrical system ground at one point only –
usually at the Building Controller, when present
Data Bus Shields: Twist
together and Isolate
with electrical tape
ECLYPSE
NET- NET + S
Figure96: Typical Cable-Shield Grounding Requirements for a BACnet MS/TP Data Bus Segment with an ECLYPSE Controller located
in the Middle of the Data Bus
Using Repeaters to Extend the Data Bus
A BACnet MS/TP data bus segment can be up to 1220 meters (4000 feet) long with up to a maximum of 50 devices. When
a greater length is required, a solution is to use a repeater. A repeater increases the maximum length of the data bus.
Using a Repeater to Extend the Length of the BACnet MS/TP Data Bus
Repeaters can be used to extend a BACnet MS/TP data bus up to 3660 meters maximum total length. Do not use more
than two repeaters on a BACnet MS/TP LAN.
A BACnet MS/TP repeater is a bi-directional device that regenerates and strengthens the electrical signals that pass
through it. It creates two electrically-isolated BACnet MS/TP data bus segments that transparently enable devices on one
side of the repeater to communicate with any device on the other side. The two BACnet MS/TP data bus segments have
the same requirements of an ordinary BACnet MS/TP data bus segment; that is, each BACnet MS/TP data bus segment:
£ Can be up to 1220 meters (4000 feet) long.
£ The first and last device on the data bus must have End-of-Line (EOL) termination resistors connected across the two
data lines/wires of the twisted pair.
£ Must respect the maximum limit for Device Loading.
£ Will have the same network number as they remain part of the same network or LAN.
It is recommended that you connect no more than 50 ⅛ or ½-load devices on all BACnet MS/TP Data Bus repeater seg-
ments when a baud rate of 19 200 or higher is used (preferably 38 400 baud). This is to ensure that the BACnet MS/TP
Data Bus has enough bandwidth to efficiently communicate network variables between controllers.
Do not use more than two repeaters on a BACnet MS/TP data bus.
A repeater can only connect two BACnet MS/TP data bus segments even if it has ports to support more than two BACnet MS/TP data bus
segments.
A repeater can be added anywhere to a data bus segment including the end of the segment as shown below.
BACnet MS/TP Communication Data Bus Fundamentals
98
nLight ECLYPSE

Acuity Controls nLight ECLYPSE Specifications

General

Brand	Acuity Controls
Model	nLight ECLYPSE
Category	Controller
Language	English