The MDB Specification for lay people

0 minute read 08 October 2011

I'm mainly working off of the specifications document by the NAMA people located at


GRN 6 MCommon 3 NC RED 5 MTX 2 0DC BRN BLK 4 MRX 1 34DC WHT

Serial Communications:


1 start bit, 8 bits data, 1 mode bit, 1 check bit, 1 stop bit

check bit

  • drop carry byte, address+all data bytes.
  • A checksum will not be performed on ACK, NAK, or RET bytes.

mode bit-

  • from vmc sets if byte is address
  • from slave if last byte of data (or finished talking to master?)

transmit nrz

receive inverted


"Each peripheral should be polled every 25-200 milliseconds. This can be done by

the POLL command or any other appropriate command."

Mtx need to source 100ma in order to drive optos!


Vertical Header: Molex 39-28-1063 ~1.25 on digikey

Right Angle Header: Molex 39-30-1060 ~1.25 on digikey