Converting an isolated Metasys BACnet/IP network to a connected Metasys BACnet/IP network - Metasys - LIT-12012458 - Field Device - 13.0

Metasys IP Networks for BACnet/IP Controllers Technical Bulletin

Brand
Metasys
Document type
Technical Bulletin
Document number
LIT-12012458
Version
13.0
Revision date
2023-10-23
Product status
Active
Language
English

A Connected Metasys BACnet/IP network is a variation of an Isolated Metasys BACnet/IP network. A Connected network is in essence an Isolated network which is connected to the IT network by way of a single Ethernet cable and IT IP address.

While it is possible initially to deploy a BAS IP network following a Connected network architecture, it is anticipated that in most cases the BAS IP network will initially be deployed as an Isolated network (for example, during new construction prior to the availability of the IT IP network), and will later be converted to a Connected network once the IT IP network is available. As described in Planning an Isolated Metasys BACnet/IP Network above, if the Isolated network was planned with an end goal of converting it to a Connected network, the actual conversion of the Isolated network to a Connected network requires very minimal configuration changes on the BAS switches.

Figure 1 below illustrates a connected network that has been converted from the isolated network that is shown in Figure 1.

Figure 1. Connected Metasys BACnet/IP network example

Note: The isolated network in Figure 1 and Connected network in Figure 1 are identical except for the following differences:
  • The BAS aggregation switch now connects to the IT network rather than the firewall.
  • The Metasys server now connects to the IT network rather than the BAS aggregation switch. This is possible because the network engine s resided in VLAN 5 and subnet 192.168.5.0/24 in the Isolated network, which matches the VLAN and subnet allocated to the BAS network by the customer’s IT department. Since the network engine s now reside in the IT network address space, the Metasys server can reside anywhere in the IT network and still access the network engine s.
  • The network engine s can connect to a remote IP controller in the IT network. This is also possible because the network engine s resided in VLAN 5 and subnet 192.168.5.0/24 in the Isolated network, which matches the VLAN and subnet allocated to the BAS network by the customer’s IT department. Since the network engine s now reside in the IT network address space, the network engine s can communicate with other BACnet devices in the IT network.