Connect the MMDVM to the Mastr III T/R shelf backplane as follows:
MMDVM — MIII Backplane
Ground — P5.4 (AGND) Note: This is an audio ground and is required for MMDVM. DGND will not work.
RXA — P2.5 (RCVR_VOL/SQ_HI)
TXA — P3.1 (GETC_DATA)
PTT — P3.3 (LOCAL_PTT)
COS — Leave disconnected. If you connect this your COS going active will disable the MMDVM output.
Then use MSEDIT to write the following special configuration to your station:
Note: If you write a new or updated station personality you may have to reprogram these parameters in MSEDIT.