11.5. NMEA2000-out technical details
11.5.1. NMEA2000 Glossary
Here is a glossary to help with the interpretation of this text:
• Virtual-device: a Battery Monitor, Inverter, or other Victron device that does not have a CAN-bus port by itself, made available
“virtually” on the CAN-bus by the NMEA2000-out function of the GX Device.
• CAN-bus: the VE.Can port on the GX Device, that, in the context of this chapter, is most likely connected to a NMEA2000
network.
• NMEA2000-out function: the software feature in the GX Device, which is described in this chapter.
• NMEA2000: Marine CAN-bus protocol, based on J1939.
• Instance: there are many types of instances, and explained in detail below.
• J1939: A set of standards defining a CAN-bus protocol, defined by the SAE organisation.
• Address Claim procedure (ACL): a mechanism, specified by J1939 and used in NMEA2000, which used by devices on the
network to negotiate and assign each device on the network a unique network addresses. Its is a number from 0 to 252. There
are three special network addresses defined:
1. 0xFD (253) - Reserved
2. 0xFE (254) - Unable to claim address - for example when all others are in use
3. 0xFF (255) - The broadcast address
11.5.2. NMEA2000 Virtual-devices
When the NMEA2000-out feature is enabled, the GX Device acts as a bridge: it will make each Battery monitor, Inverter/charger
or other device that is connected, available individually on the CAN-bus.
Individually, as in each with its own network address, its own device instance, function codes, and so forth.
For example, a GX Device with two BMVs connected on a VE.Direct port and an inverter/charger connected using VE.Bus, will
make the following data available on the CAN-bus:
Table 2.
Address
Class
Function
Description
0xE1
130 (Display)
120 (Display)
The GX Device itself
0x03
35 (Electrical generation)
170 (Battery)
The 1st BMV
Color Control GX Manual
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Marine MFD integration by NMEA2000
