Multiple master busses?

Kevin Arscott 3 years ago updated by Thomas Moberg (System support) 6 months ago 4

We have an application where it utilises the maximum capability of an MC43FS. Can we run a second dedicated master bus (probably an MC41FS) directly between the two modules (no other modules connected except MC43FS and MC41FS) to give us full APP IN / OUT and additional performance capability? We would normally just add the MC41FS onto the main master bus but this is handling quite a bit of non safety critical info to an MD4, we just don't want to overload it with safety APP IN / OUT to share safety calculation between modules.

IQAN Design 5.01 does not hint or produce errors when checking the project with two master busses. Does the software know which bus to 'listen;' for a certain module APP IN or OUT?


IQANdesign keeps track of which bus (or buses) to send out each APPOUT, so yes, you can have multiple master buses. APPOUT's that are only used by APPIN's on the MC41FS will not be sent on the master bus to the MD4.

If I have two Master buses connected between the same two MC43FS's does the software automatically try to balance the traffic between the two master buses? 

Not sure. Rig up the system and measure the traffic using IQAN Analyse, that would be a good way to establish if its shared.


It will not share the load between the buses, it will be the same traffic on both buses.

So you can lose either one of the busses and the receiving APPIN channels will still work.