Just to be on the same page, we are talking about virtual throttles number in JMRI, right? not total engines number. Because there could be consisted sets of engines.
Also, do not forget that if you run warrants or automatic running, those do count as more virtual throttles.
I built a DCC++ based system for my club, and it certainly can operate
multiple locos from a WIFI input to the JMRI computer.
The base DCC++ is memory limited on an Arduino UNO, but stripping out
what's not need specifically for operating the trains themselves, 35 or
so locos can be run concurrently.
I'm in process building a system base on an Arduino MEGA, and that
should be able to run many more trains. That exact number will be
determined, but I expect it to be 200 or more. Be aware that the basic
architecture of the DCC signal limits the number of packets to about 110
per second. DCC doesn't send every packet to every loco continuously, so
the number of packets needed to actually operate a loco is dependent on
what the loco is doing. If every loco had a packet sent to it, after 110
locos, the response time would suffer, but that would be regardless of
the system used.
I had an friend whose club uses an NCE system, and since NCE treats each
loco, even in a consist as a separate loco, every loco gets commands
sent to it as required, where most other system only send commands to
the consist address. Having said that, the friend has never had any
issue operating, even on a large modular layout in a convention center.
The layout was so large that one 'loop' around it took 45 minutes
without stopping.
