Mixer User Manual

10
ADVANCED FUNCTIONS
LOGIC CONNECTION SPECIFICATIONS
The SCM410 logic functions expand the range of installation and con-
trol options. Logic can be used for everything from simple cough switches
to elaborate computer-controlled room systems. (Shure's AMS Update
publication contains additional applications of advanced logic. This publi-
cation is available by contacting the Shure Applications Department.) The
following logic functions are available for each channel:
GATE OUT: Follows channel gating and goes to logic “low” (sinks cur-
rent) when microphone is gated on. 500 mA of current sinking ability is
provided (see Figure 5A).
MUTE IN: Applying logic “low” (from GATE OUT or a switch closure to
logic ground) gates channel off (see Figure 5B). Channel output drops to -
∞ .
OVERRIDE IN: Applying logic “low” (from GATE OUT or a switch clo-
sure to logic ground) forces channel on (see
Figure 5B ). When both Mute
and Override are activated, Mute takes precedence (see Internal Modifi-
cations for Override precedence).
LOGIC GROUND: Logic ground is distinct from audio ground. Make all
logic ground connections to this pin, including power supply ground of ex-
ternal logic circuitry. To avoid switching clicks, do not connect logic
ground to audio, chassis or rack grounds.
Logic controls are accessed through the high density DB-15 multi-pin
connector on the rear panel (Figure 6). Pin connections are shown in the
following table.
LOGIC CONNECTIONS
CAUTION: Use of Advanced Functions is recommended only for qualified audio technicians.
55K
10K
+5 V
+5 V
AB
LOGIC EQUIVALENT CIRCUIT DIAGRAM
FIGURE 5
FROM
SCM410
CIRCUIT
GATE
OUT
LOGIC
GROUND
MUTE IN
OR OVER-
RIDE IN
TO
SCM410
CIRCUIT
LOGIC CONNECTOR
FIGURE 6
Pin
No.
Logic Function Logic Function Pin
No.
1 OVERRIDE IN 1 GATE OUT 1 6
2 OVERRIDE IN 2 GATE OUT 2 7
3 OVERRIDE IN 3 GATE OUT 3 8
4 GATE OUT 4 GATE OUT 4 4
5 LOGIC GROUND OVERRIDE IN 1 1
6 GATE OUT 1 OVERRIDE IN 2 2
7 GATE OUT 2 OVERRIDE IN 3 3
8 GATE OUT 3 OVERRIDE IN 4 14
9 NO CONNECTION MUTE IN 1 11
10 MUTE IN 4 MUTE IN 2 12
11 MUTE IN 1 MUTE IN 3 13
12 MUTE IN 2 MUTE IN 4 10
13 MUTE IN 3 LOGIC GROUND 5
14 OVERRIDE IN 4 NO CONNECTION 15
15 NO CONNECTION NO CONNECTION 9