Which installation example would require device instancing?

• A. 1 Transducer.
• B. 3 Transducers.
• C. No Transducers
• D. 2 Transducers.

Answer: (D)

On an NMEA 2000 network, device instancing is used to tell apart multiple devices of the same type on the same bus. Each device has a device instance value that differentiates it from others of the same type, so messages from the two transducers don’t get confused.

If you have two transducers of the same type, you must assign different instances (for example, one as 0 and the other as 1). That way, data from each transducer is identified correctly in the network streams. With only one transducer, the default instance (0) is sufficient, so no special instancing is needed. No transducers means there’s nothing to distinguish, so instancing isn’t required.