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--- ve.can:changing_nmea2000_instances [2023-04-13 20:50] – [1.3 Recommend instancing setup for main MFD brands] mvader
+++ ve.can:changing_nmea2000_instances [2025-02-06 22:04] (current) – [1.3 Considerations before changing instances] mvader
@@ Line 13: / Line 13: @@
 There various types of instances, and for marine systems are two that matter: the Device instance and the Data instance. The data instance goes by various different names, like Fluid instance, Battery instance and DC instance.
-Details and differences of each type are explained in detail in the [[https://www.victronenergy.com/media/pg/Cerbo_GX/en/marine-mfd-integration-by-nmea2000.html|Cerbo GX manual, NMEA 2000 chapter]].
+Details and differences of each type are explained in detail in the [[https://www.victronenergy.com/media/pg/Cerbo_GX/en/marine-mfd-integration-by-nmea-2000.html|Cerbo GX manual, NMEA 2000 chapter]].
-**WARNING**: whilst it is possible to change the Battery and DC instances on a Skylla-i battery charger, changing those will render it impossible for a GX device to properly read the data. This is because the GX device expects the charger's output one to be on Battery & DC instance 0, output two on Battery & DC instance 1, and output three on Battery & DC instance 2. Changing the fluid instance, as well as other data instances for PGNs transmitted by a GX device on a NMEA2000 network using its NMEA2000-out feature, is no problem.
+==== 1.3 Considerations before changing instances ====
-Note that its only rarely necessary to change either device or data instances like the Fluid-, Battery- and DC-instance. See next section.
+First of all, note that it is only rarely necessary to change either device or data instances like the Fluid-, Battery- and DC-instance. Other sections in this document explain the specifics per make of MFD brand (Garmin, Raymarine, others).
-==== 1.3 Recommend instancing setup for main MFD brands ====
+When it is necessary or required to change instances, then depending on the type of product and system used, changing instances could also affect behaviour of the Victron equipment. In more detail:
+**GX devices, NMEA2000-out feature**
+All instances of the transmitted by a GX device can be set to any value, there is no related functionality. Includes device instances, and data instances.
+**Other products: Device instance**
+The NMEA 2000 device instance, which is the same as the VE.Can device instance, is by default set to 0 on all Victron products.
+Some products, such as Lynx Smart BMS, Solar chargers with a VE.Can port and Battery chargers with a VE.Can port, have functionality that relates to the device instance. Therefore make sure to read the manual of that product before changing the device instance.
+**Battery chargers: Data instances (Battery- and DC instance)**
+Whilst it is possible to change the Battery and DC instances on a Skylla-i battery charger, changing those will render it impossible for a GX device to properly read the data. This is because the GX device expects the charger's output one to be on Battery & DC instance 0, output two on Battery & DC instance 1, and output three on Battery & DC instance 2.
+==== 1.4 Recommend instancing setup for main MFD brands ====
 The only common use case we encounter in testing and support where it is necessary to change instances is with older Raymarine hardware & software:
@@ Line 34: / Line 50: @@
   * [[venus-os:mfd-navico#nmea_2000|NMEA 2000 configuration for Navico (B&G, Simrad and Lowrance]])
-==== 1.4 Different methods for setting up instances ====
+==== 1.5 Different methods for setting up instances ====
 As the NMEA2000 protocol prescribes commands to change an instance by sending commands to a device, there are various ways of changing instances. The purpose of this document is to describe all commonly used methods.
@@ Line 47: / Line 63: @@
 Chapter 2, 3, 4, 5 and 6 explain these methods in detail.
-==== 1.5 Further reading on Victron and NMEA 2000 ====
+==== 1.6 Further reading on Victron and NMEA 2000 ====
   * [[ve.can:nmea-2000:start]]
   * [[https://www.victronenergy.com/upload/documents/Whitepaper-Data-communication-with-Victron-Energy-products_EN.pdf|Data communication white paper]]
-  * [[https://www.victronenergy.com/media/pg/Cerbo_GX/en/marine-mfd-integration-by-nmea2000.html|Cerbo GX manual, NMEA 2000 chapter]]
+  * [[https://www.victronenergy.com/media/pg/Cerbo_GX/en/marine-mfd-integration-by-nmea-2000.html|Cerbo GX manual, NMEA 2000 chapter]]
   * [[https://community.victronenergy.com/topics/NMEA%202000%20-%20N2K.html|NMEA2000 related discussions on Victron Community]]