Download Communication Bus, Ethernet - Guide Specifications (Controls)

Building Control (Field Installed)
Communication Bus, Ethernet
Communication Bus, Ethernet - Guide Specifications (Controls)
2.1.3
Communications Bus (When Part of a Network)
2.1.3.1
General: Wiring and Raceways
Provide copper wiring, plenum cable, and raceways as specified in the applicable
sections of Division 16.
All insulated wire to be stranded copper conductors, UL labeled for 90C minimum
service.
The Communications Bus shall be a three-conductor cable with shield. EIA
Standard RS-485 Communication’s protocol shall be employed. The
communications bus shall comply with FCC Part 15, Subpart J, Class A for bus
radiated and conductive noise.
Communications Bus shall be capable of having multiple system elements
connected. Each Communications Bus shall allow for the use of modules as an
interface to secondary Buses.
Whenever the Communications Bus enters or leaves a building, the Bus shall be
provided with adequate lightning suppression devices.
The Communications Bus shall be capable of communicating through a
telephone modem to a remote building. This interface shall allow any EMS
operator’s station, as applicable, to communicate with any other remotely
located, compatible, communications bus.
2.1.3.2
Network Communications
The communications infrastructure shall be capable of supporting a two-tiered
physical architecture consisting of an RS-485 Layer and Ethernet Layer. All
controllers and system interface devices shall maintain a peer-to-peer flat,
logical, communications architecture from either physical layer. The infrastructure
shall rely on the use of communications routers that will encapsulate messages
on the RS-485 layer and pass them to or through the Ethernet layer. These
routers shall provide a seamless, transparent connection from the RS-485 layers
or segments to an Ethernet backbone, network, as well as to computers with a
direct Ethernet connection. The Ethernet routers shall have full communication
capability with the DDC network without loss of dynamic data or functional control
tables.
The RS-485 communications segments shall have the capability to be connected
using a minimum of 200 Ethernet routers in order to extend the RS-485
communications segments over the Ethernet. The Ethernet routers shall support
flexible Internet Protocol addressing. The Ethernet routers shall support either
static or Dynamic Host IP address assignments. Addressing shall be capable of
being done in more than one way. A standard Windows tool such as
HyperTerminal shall allow a non-HVAC technician to commission the Ethernet
router. The Ethernet router shall also be able to be fully commissioned using a
standard commissioning tool that an HVAC technician is familiar with.
The Ethernet router shall have the following minimum components and
capabilities:
 32 Bit Micro Processor
 10Base-T Ethernet Port
 RS232 Console Port
 RS485 Network Port
 Status and Communication LED’s