dm1 to multi master using appin/appout

Do you need to pass the DM1 messages to use them in the application logic on the different masters? 

If the need is to only see the SPN channel pop-up dialogues when there are errors then it is easy, dialog messages are passed automatically on the Diagnostics bus, just as the other error messages. Can be disabled with the "show messages" property on the display pages for the different MD4 modules.

If you need to read the DM1 and SPN channels in the application logic, it is more tricky, the J1939 module in IQANdeisgn has a limit on maximum one DM1 channel per module. I never thought of this as a problem, but it looks like this limit applies regardless of whether the DM1 channels are on separate masters. 

An option if you have an MC4 as the master module physically connected to the J1939 module, and you want to pass traffic along to other masters, then you could use the new CAN routing feature. 

I would just like to see the popup dialogues. I was unaware the SPN would be sent through the Diagnostic bus though and not on the connected J1939 bus. Is there a way to dictate what screens will display each DM1 message? I am connecting multiple engines and screens so to eliminate confusion on what engine is having an issue i would prefer that a DM1 fault from engine one does not pop up on the engine two screen but they both pop up on the master screen that is remote of the two engines(i could end up with as many as 6 engines). Also is there a way to set popups to show on designated pages only?

The J1939 DM1 message containing the diagnostic trouble codes (SPN/FMI) are of course sent over the J1939 bus.

IQAN (internal) dialogue messages are sent over the diagnostics bus.

If you have display 1 control J1939 engine 1, display 2 control J1939 engine 2, etc. you can set the Show message property to 'Own' on the DM1 channel. But then you would need one separate display master controlling each engine.

Is there a way to read the DM1 from a single engine on multiple IQAN masters?  I have an application that we want to use a touch button on a MD4-7 to directly access the engine log to see the DM1 messages.  It is only possible to directly access a log file on the same master that the touch button is located.  There is a common J1939 bus between several IQAN masters and due to increasing the bus load, we cannot place the engine module on that bus so the information is easily shared between masters.  The engine J1939 is currently connected to a CAN bus on a MC43. We can use another bus on the MD4-7 to tap into the CAN bus for the engine which will have the engine J1939 feeding to the MD4-7 and MC43.  This will allow J1939 messages from the engine to go directly to both masters.  I would like to directly read the DM1 messages on both masters; the MD4-7 and MC43.  This will allow the MC43 to read all the CAN messages including the DM1 message for logic purposes and allow direct access to the DM1 logs on the MD4-7 via touch button.  

In summary, I would like to have a common CAN bus between a J1939 engine, MC43 and MD4-7 and allow both the MC43 and MD4-7 to read the engine CAN frames and DM1 messages.

You can duplicate the JFIN channels that you need on both masters (the wheel loader example file with MD4 and MC43 shows this)

But you can have only one DM1 in (and related MDGN) channels per J1939 module. 

In a system with one MD4 and one MC43, I think it is best to only duplicate a few JFIN channels on the MC43, those that are needed for machine control. And have the DM1 channel and the linked channels for SPN names on the MD4. 

However, if you need the MC43 to react to a specific DTC, you could move all the DM1 related channels to the MC43. The MD4 will show the popup messages from the MC43 , and you will be able to see the see the DM1 and DM2 list. 

There are two drawbacks as I see it; it puts a bit more traffic on the diagnostics bus, and more channels on the MC43 that has less memory available.