Estimating - Metasys - LIT-12012005 - Field Device - N2 Controller - 13.0

Modernization Guide for N2 Controllers - Metasys

Product name
N2 Controller
Document type
User Guide
Document number
Revision date

When planning for N2-capable equipment controller implementation, it is important to consider all of the related hardware changes as well as how long it may take to replace an item in the field using the new controllers. Be aware of the time, cost, and benefits prior to starting the project. Customers need to be aware that they will need to learn a new programming tool (CCT).

You can shorten or eliminate the application development time when replacing several devices with the same configuration.

Conduct a Site survey using the following questions:

  • Are all I/O in use?
  • What I/O devices are in use?
  • What I/O signal types are in use?
  • Is the old configuration file or control sequence description available?
  • Is the sequence of operation still relevant?
  • Will the existing controller enclosure be suitable for the N2-capable equipment replacement?
  • How is the controller involved with the supervisory-level software?

Research the old installation as follows:

  • If the installation was developed using AIM Tools Standard System Library, an equivalent BACnet system configuration can be used as a starting point.
    • Look for the N2-Fixed standard number in drawing title block N2-Fixed systems number from 1,000 to 10,000.
    • Add 20,000 to the original N2 Standard System number to locate the equivalent BACnet-Fixed configuration. Example:

      Mixed Air Single Duct with Variable Volume Supply Fan (VFD), and 4 Stage DX Cooling Coil.

      N2-Fixed ID# 1210

      BACnet-Fixed ID# 21210

  • If the old installation did not use the Standard System Library, use the original sequence of operations and point list to select a similar system in the BACnet Configurable group.

Without the original installation documentation, the time needed to replace a legacy N2 controller is minimized if you are able to locate the controller configuration file for the damaged device.

Without the controller configuration file, you must analyze the mechanical equipment characteristics and control sequence. Then confirm your new sequence with the customer before implementing.