In order for Events2HVAC to discover and communicate to a BACnet network from a different subnet, it needs to connect as a foreign device to a BBMD device (BACnet Broadcast Management Device). Typically each BACnet network on a separate subnet needs to have one (and only one) BBMD device so that BACnet messages are broadcast to the other subnets via the BBMD.
JCI MSEA devices normally handle this assignment automatically, behind the scenes, using the Dynamic Broadcast Management feature. Here's the definition from Metasys Help:
Dynamic Broadcast Management
When a Metasys system includes more than one IP subnet, the Dynamic Broadcast
Management feature automatically configures the Metasys system with BACnet
Broadcast Message Devices (BBMDs) so that BACnet protocol broadcasts reach
all Metasys system devices. The feature automatically determines the number of IP
subnets and ensures that each IP subnet has exactly one BBMD. The feature uses
the Third Party BBMDs List attribute when determining the list of devices to be
When True, the selection of broadcast management devices occurs automatically
as devices are added or removed from the site. When False, the selection of
devices occurs only when the Update Broadcast Management command is issued
to the site.
In the case where all the Metasys BACnet devices are on the same subnet AND the Events2HVAC server is on a different subnet, you will need to tell the Site Director which Metasys controller will be designated as the BBMD device. This is done by adding ONE Metasys device to the list of 3rd Party BBMD's in the Site Director.
Here's the definition of the Third Party BBMDs from Metasys Help:
Third Party BBMDs
The Third Party BBMDs attribute is used by the Dynamic Broadcast Management
feature to help determine the placement of BBMDs.
BBMDs are used in the BACnet protocol to eliminate broadcast messages sent
across multiple subnets on an IP network. A single device on each subnet, referred
to as the BBMD, receives messages from other BBMDs and broadcasts them
locally on its own subnet.
If one or more third-party BBMDs exist, this attribute should specify the complete
list of IP addresses of third-party BBMDs and Metasys system devices that should
act as a BBMD. Each IP subnet should have exactly one BBMD, either a
third-party or Metasys system device. To function properly, each third-party
BBMD must be configured with the list of all other BBMDs within the system as
If the Metasys system does not include any third-party BBMDs, then this attribute
typically should be left empty. A possible exception would be if you want to
designate a particular Metasys system device as a BBMD, then that device could
be added to the Third Party BBMD list. If no device is specified by this attribute
for an IP subnet, the Dynamic Broadcast Management feature automatically
assigns a Metasys system device. Do not specify more than one Metasys system
device per IP subnet.
Once a Metasys controller is defined in the 3rd Party BBMD list, that controller's IP address can be used to connect to the BACnet network using a foreign device connection from a different subnet.
Figure 1 - Foreign Device Connection to Remote BBMD
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