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J1939 DM2 viewing

Gustav Widén (System support) 5 years ago in IQANdesign • updated by Mark Walser 1 year ago 7
In IQANdesign 3.14, a function to view DM2 on the IQAN-MD4 was introduced. 
DM2 (Diagnostic Message 2) is the J1939 method for sending old error codes, as opposed to DM1, that are used for active error codes.
Just like DM1, the DM2 consists of SPN (Suspect Parameter Number) and FMI (Failure Mode Identifier). For DM2, another value is also relevant, the OC (Occurrence Count).

In the IQAN-MD4 menu system, select Info, Modules and the J1939 module you want to view.


Here you will see a list of all the currently active faults, DM1. 
The clear text interpretation of the SPN (e.g. Engine oil pressure for SPN 100) is taken from the SPN channel name in IQANdesign. 

To get DM2 messages, press the menu symbol to the right.


To view the DM2, you will need a physical MD4, here is an example of how the list could look:

For both DM1 and DM2, there is a limit of maximum 10 unknown SPN:s that do not correspond to a SPN channel. If you have more unknown SPN:s, you will not see them all.

Note that you will have to enable DM2 in the application. The property is on the DM1 channel. Only works on MD4.

This is a great addition, this will allow my company to use this display in many more applications. Couple questions: can we make the page accessible by a button on a screen, separating it from the Menu. Also can we hve the ability to rename the pages, as the end users will probably not be familiar with DM1 and DM2
Planned
4.x will make it possible to access a module in the menu system via a button action. That would take you to the DM1 view for a J1939 module. Good input about the naming, I'll add a request for it.

Is it possible to clear the DM2 messages with this block functionality?   

The menu system does not have any function for clearing the old error codes from the J1939 module, we did not want to include such a function as it could potentially be misused. But you could make your own DM3 (clear diagnostic data) using either JFOUT requesting it or JFIN with the "poll trigger" property (the function for request PGN). I am not sure of exactly what you would be able to clear with this, I am under the impression that there are some limits to this. 

Is it possible to read the Lamp Status from the DM1 block?

When you have the built in DM1, you can place MDGN channels on the J1939 module to read the lamp status. 

A limitation in the existing versions is that the lamp blinking is not shown.