Connecting BACnet ARCNET network and a BACnet/IP network

BR2-A BACnet Router

BACnet has the same protocol for the monitoring, automation and field levels. It is unified top to bottom. BACnet field controllers with direct I/O and application specific features (B-ASC) can communicate all the way up to BACnet/IP Operator Workstations (B-OWS) and BACnet Building Controllers (B-BC).

In order to interconnect such levels, a BACnet Router is needed. The Cimetrics BR2 is such a BACnet Router. For BACnet/IP the interface is 10/100 Half/Full Duplex RJ45 standard Ethernet station-side. The ARCNET side is 2.5 Mbps using standard 93 Ohm RG-62 coaxial cable.

The BACnet/IP port on the BR2-A connects to the network Ethernet/TCPIP port using a standard CAT5 cable. The ARCNET port connects to the target BACnet ARCNET LAN (93 Ohm RG62 Coaxial cable or RS485 twisted pair plus ground cable in general). The BR2-A can be powered from any 120VAC source. The BR2-A is setup using its embedded webpages.

The ARCNET LAN must have a BACnet Network Number unique from the BACnet Network Number assigned to the BACnet/IP network connection. Nothing precludes the use of multiple BR2-A routers ion the same ARCNET network as long as unique BACnet network (and ARCNET LAN MAC) assignments are made for each created BACnet/IP configuration access network.

Bridging BACnet Automation and Field Levels with Multiple Routers

BR2-A BACnet Router

Multiple BACnet Routers can reside within the same BACnet internetwork. A group of ARCNET devices located along an ARCNET LAN, spread in any fashion which adheres to the ARCNET cabling rules, can be bridged to a BACnet/IP network with a BACnet Router. So too can any others like ARCNET, MSTP (or any supported BACnet datalink) be attached using another BACnet Router.

This means of extension is often better than extending existing ARCNET (or MSTP) networks using repeaters. It can also help alleviate LAN loading problems with token collisions, node numbers and cable lengths.

The BACnet/IP port on the BR2-A connects to the main network Ethernet/TCPIP port using a standard CAT5 cable. The ARCNET port connects to the target BACnet ARCNET LAN (93 Ohm RG62 Coaxial cable or RS485 twisted pair plus ground cable in general). The BR2-A can be powered from any 120VAC source. The BR2-A is setup using its embedded webpages.

The ARCNET LAN must have a BACnet Network Number unique from the BACnet Network Number assigned to the BACnet/IP network connection. Nothing precludes the use of multiple BR2-A routers ion the same ARCNET network as long as unique BACnet network (and ARCNET LAN MAC) assignments are made for each created BACnet/IP configuration access network.

Commissioning a BACnet ARCNET device using a BACnet/IP Laptop or other Commissioning Computer

BR2-A BACnet Router

To commission BACnet ARCNET devices one has generally been forced to use a special PC hardware ARCNET interface to communicate with the ARCNET RS485 or Coaxial LAN. The secret is that most BACnet ARCNET software can be run against BACnet/IP and communicate via BACnet Routing to BACnet ARCNET to achieve this configuration/setup connectivity. The Cimetrics BR2-A can accomplish this connectivity. The BACnet/IP port on the BR2-A connects to the PC’s Ethernet/TCPIP port using a standard CAT5 cable. The ARCNET port connects to the target BACnet ARCNET LAN (93 Ohm RG62 Coaxial cable or RS485 twisted pair plus ground cable in general). The BR-A can be powered from any 120VAC source.

The BR2-A is setup using its embedded webpages. The baud rate of the BACnet ARCNET port is setup to match the baud rate and network number of the existing ARCNET LAN.

The ARCNET LAN must have a BACnet Network Number unique from the BACnet Network Number assigned to the BACnet/IP network connection created by the PC connection. Nothing precludes the use of multiple BR2-A routers ion the same ARCNET network as long as unique BACnet network (and ARCNET LAN MAC) assignments are made for each created BACnet/IP configuration access network

BR2 Router – BACnet Network Router

BR2-A BACnet Router

The BR2 router provides routing between BACnet networks such as BACnet/IP, BACnet ARCNET, BACnet Ethernet, and virtual or tunneled BACnet networks. This allows integrators to mix and match BACnet network datalink technologies within a single BACnet Internetwork. The BR2 router has two communications ports in all cases. One is always a 10/100 Ethernet port and the other can be chosen from any of the above.

The BR2 Router is enclosed in a metal case that can be mounted standalone or in a 1U rack space. It is powered by 100-240VAC at 50W at 47-63Hz  via a standard IEC line cord. The unit has one ARCNET connector and one Ethernet 10/100 RJ45 connector.

The ARCNET connector is industry standard 93 Ohm BNC connection. It operates at the standard 2.5 Mbps and by default uses normal timeouts though it can be set for one of the three available ARCNET extended timeouts settings used in long cable run segments. Logically and physically 254 devices can be addressed. The ARCNET is not terminated internally to give the user flexibility in connections and topologies used.

The Ethernet port uses a standard shielded RJ45 connector with integral LEDs. Connection status can quickly be ascertained from the Link and Activity LEDs on each interface.

An embedded web server allows for commissioning and configuration and troubleshooting via a standard web browser. A power LED is present along with the LEDs for interface status on each interface. 

Flexible routing between: 

• BACnet/IP and BACnet Ethernet
• BACnet/IP and ARCNET
• BACnet/IP and virtual or tunneled networks
• BACnet Ethernet and ARCNET
• BACnet Ethernet and virtual or tunneled networks

IP network support:

• Web server for commisiioning and troubleshooting
• Status page for diagnostiocs
• Secure login to web configuration and status interfaces
• BACnet/IP Broadcast Management Device (BBMD)
• Foreign Device Support (FD)
• BACnet Device Object support
• IP filtering and exlusion

Standard Communications:

• 10/100 Mbps Ethernet.
• Industry standard ARCNET with surge protection
• Flexible external ARCNET termination
• Convenient Installation

• 100-240VAC at 47-63 Hz at 50W
• Standard IEC cord connection to mains 47-63Hz 100-240 VAC
• Available 1U server rack mount shelf
• Available DIN rail mounting bracket. 

Specifications - BR2-A BACnet/IP to BACnet ARCNET Router

Overall:

• Power: 120VAC at under 50W
• Operating temperatures: 0 to 40C
• Storage temperature: -20 to 80C
• Relative Humidity: 10-95% non condensing
• Physical protection: IP30 DIN EN 60529 (VDE 0470) (no entry of 2.5mm probe, NOT waterproof)
• System LED: power as labelled  ON=OK

Ethernet:

• IEEE 802.3 10/100 MBPS
• 10BaseT, 100BASETX phsyical. RJ45 connectors
• Half/Full duplex
• 100m (max) CAT5 cable length.
• LEDs: link and activity as labelled.

ARCNET:

• ANSI/ASHARE 135 (ISO 16484-5)
• 2.5 MBPS data rate
• RG-62 93Ohm coaxial bus physical layer
• 1200m (abs max) cable length
  (Rule of thumb: nodes x km length x termination and dielectric flaws should not exceed three)
• LEDs: link and activity as labelled.

Regulatory Compliance: FCC and CE marked

Options:

• Rack mounting kit.
• External network surge protector.

Documentation: B3050 BR2-A

BACnet ARCNET to the central IP Network

•  B3050 Data Sheet.pdf (160.23 kB)
•  B3050 Login (114.11 kB)
• User manual. Self documenting simple web user interface.
•  B3050 Limited Warranty (24.51 kB)
•  B3050 Warnings (29.96 kB)