Message
Re: NRPN in the BCN44
2014-10-21 by markwinvdb@...
Sorry for not responding sooner, but I don't visit this forum as regularly as I used to,
since I set up a BC2000/BCN44 forum at my own website (mountainutilities.eu) about a year ago.
Concerning your question: my BCN44 exhibits the same behavior you noticed.
For encoders using the "Absolute 14-bit" NRPN range, the BCN44 outputs the wrong data value for certain Data MSB messages, as follows:
Display => SentMSB SentLSB
0 => 1(should be 0) 0
127 => 1(should be 0) 127
128 => 1(correct) 0
255 => 1(correct) 127
256 => 3(should be 2) 0
383 => 3(should be 2) 127
384 => 3(correct) 0
511 => 3(correct) 127
512 => 5(should be 4) 0
639 => 5(should be 4) 127
640 => 5(correct) 0
So the BCN wrongly adds 1 to any EVEN Data MSB value.
So unless I'm much mistaken, the BCN44's firmware contains a weird bug concerning "Absolute 14-bit" NRPN messages, and there's nothing we can do about it.
By the way, my BCN44 has firmware version 1.02, as indicated in the display after power-on; I assume that yours is the same?
Mark.