How does "DCA MUTE" work?
When you choose to use the DCA mute, it is similar to bringing the DCA fader down. What that means is that only the Post Fader sends on those channels assigned to that DCA group will be affected, not the Pre-Fader sends.
Using the Mute groups, however, will affect all the sends from the channels assigned to that Mute group--Pre Fader and Post Fader. This turns the channels off.
PM5DV2 has an unique option for the DCA MUTE function, which can be found in the PREFERENCE1 screen.
DCA MUTE TARGET (Owner's Manual p.205)
This specifies whether the DCA [MUTE] key will mute the send to the MIX bus when the send-source to the MIX bus is PRE FADER. If you specify “POST ONLY,” the PRE FADER signal will not be muted. If you specify “PRE & POST,” it will be muted regardless of the send-source position.