Is there a standard rule about how quickly sequential CV write packets can be sent to a decoder? Is there a certain amount of delay (in milliseconds) that must be allowed between write commands? I'm working with SoundTraxx decoders right now, but I'm interested in this topic in general. The NMRA spec says decoders should handle back-to-back commands, but maybe that doesn't always work.
Hello All,
At the speed of electrons is the simple answer!
With our current understanding of quantum physics- -it depends on the molecular makeup of the transmission medium.
Now- -how "fast" can particular conductors transmit this information?
Fiber optics would produce a "faster" response than traditional copper or aluminum conductors, with their respective resistance.
But at what increased cost?
I don't know of any modeler using fiber optics to "wire" their pike.
To answer your question in depth I suggest you get the Digitrax Big Book Of DCC.
It delves into the packet sequence and how these interface with the waveform of alternating current along with showing the waveform on oscilloscopes and graphs.
There are "preamble" digital packets that alert individual decoders; after being "assigned" an address, to accept or ignore command packets- -all at the "speed" of electrons.
All are limited by the conductor(s) carrying capacity.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
Depends on the decoder in question. Some can handle commands faster than others. So designers of DCC systems have to consider that some may fail if the commands are sent too quickly, and will manage that rate accordingly.
A LokProgrammer can read an ESU decoder in a matter of minutes what would take JMRI an hour (more or less) because of a custom communications protocol unique to ESU.