Scenario 3: system modernization - Metasys - LIT-12012005 - Field Device - N2 Controller - 13.0

Modernization Guide for N2 Controllers - Metasys
Product
Network and Communications > N2 Controls > N2 Controller
Document type
User Guide
Document number
LIT-12012005
Version
13.0
Revision date
2023-10-16

In this scenario, the customer has an N2-based BAS and has previously replaced legacy N2 controllers with N2-configured equipment controllers as part of an earlier replacement scenario. Now the customer is contemplating future risk and the cost and disruption of more legacy N2 controller replacements.

Option 1

You should consider modernizing the BAS to use BACnet MS/TP protocol. This option requires replacing the N2 only supervisor with a BACnet supervisor, switching the existing N2-configured N2-capable equipment controllers to BACnet, and replacing the remaining legacy N2 controllers with BACnet-configured N2-capable equipment controllers.
Note: If the existing N2 supervisor also supports managing BACnet MS/TP networks, then the supervisor may not need to be replaced. See Converting to BACnet MS/TP Field Bus for the key challenges to this option.

For example, one strategy could be to incorporate the installation of a network engine, configuring one trunk to the existing N2 and configuring the other to a new BACnet MS/TP. The BACnet trunk could then be run parallel with the existing N2 trunk and you can replace non-functional N2 controllers with BACnet MS/TP, or the remodeled area could be BACnet MS/TP while the existing un-renovated areas could remain N2. Then when the customer’s budget allows, the remaining N2 areas could be converted to MS/TP and the trunk 1 on the NAE/NCE or SNE/SNC could be switched to BACnet MS/TP.

Option 2

Convert N2 systems to BACnet IP controllers if the customer views uplifting their facility to the latest technology as a future-proofing strategy for their building systems.

Option 3

Use wireless field bus option. This option may not be cost effective as existing N2 bus wiring could be re-used for BACnet MS/TP when compared to the cost of the wireless hardware.