Metasys N2 by JCI - How do I terminate a line

In order to properly terminate the N2 Bus, you need to know the two types of terminating devices. They are:

• Switch-Terminating--device has an EOL switch or jumper; includes the NCM, DCM, XBN, XRE, XRL, XRM, ILC, IFC, D600, and repeater.

• Self-Terminating--device has termination built-in; includes AHU, LCP, UNT, and VAV. Figure 18 shows four examples of how to properly terminate.

Key: T T T T T (A) (B) (C) (D) SW TERM SW TERM SW TERM SW TERM SELF TERM SELF TERM SELF TERM SW TERM SW TERM SELF TERM SW TERM SELF TERM SW TERM = Switch-terminating devices. Includes NCM, DCM, XMs, ILC, IFC, D600, and repeater. SELF TERM = Self-terminating devices. Includes AHU, LCP, UNT, and VAV. T = End-of-line termination must be switched in.

Setting EOL Terminationns Follow these rules:

• Set the EOL to In for any switch-terminating device with one N2 cable connected, since this is an end-of-line device.

 • For each N2 Bus segment, at least one switch-terminating device must have its EOL set to In. This is typically the NCM or a repeater. However, the N2 Bus will be less susceptible to noise if the ends of each segment have a switch-terminating device with its EOL set to In.

• For a multislot NCU or NEU that is at the end of line, any one of the EOL switches on any of the components can be set to In. However, to maintain consistency, you may want to always use the EOL switch on the N2 device that is located in the right-most (highest numbered) slot in the NCU/NEU. Setting Terminations Rules 34 Network Communications—N2 Communications Bus

• To set the EOL jumpers on the repeater, refer to Table 4 and Figure 15. Remove the cover of the repeater to get at the EOL jumpers. Note: Sides A and B have separate EOL settings. Determine the settings individually.