Simulate and Canbus

Question for using simulate.

When testing a Project in Design we use the separate simulate program to test the design functionality. However when the deisgn uses Canbus as J1939 or CanOpen then it seems to me that I can go in and simulate a single canbus sent or received frame value to ensure that the system does what I want, but I cant simulate the live function of the canbus itself.

For example if I have a master that is sending J1939 packets to something else then is there any way I can generate that Canbus output on the Simulate PC as either a serial interface or using one of the approved USB to Canbus dongles?

So far when using one project master to talk to another master project then I dont believe I can really use simulate to test that but actually need  the 2 master IQAN modules on my desk next to design to test the implications for change and to get a feel for canbus loading etc.

Is my understanding that I cant use simulate for this correct? and is there any plan's to change simulate to cover this aspect in the future?

In my case where I use a pair of MD4-10's to talk to each other over a wireless bridge having that much hardware tied up on my desk is expensive and I don't want to pay for that if there is an alternative approach I could/should use...

Andy