CAUTION: Use of Advanced Functions is recommended only for qualified audio technicians.
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 -.
A
+5 V
10K
GATE
OUT
FROM
SCM410
CIRCUIT
GROUND
LOGIC EQUIVALENT CIRCUIT DIAGRAM
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 Addendum 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 CONNECTOR
ADVANCED FUNCTIONS
B
+5 V
55K
MUTE IN
OR OVER-
RIDE IN
LOGIC
FIGURE 5
FIGURE 6
LOGIC CONNECTIONS
Pin
Logic Function
No.
1
OVERRIDE IN 1
2
OVERRIDE IN 2
3
OVERRIDE IN 3
4
GATE OUT 4
5
LOGIC GROUND
6
GATE OUT 1
7
GATE OUT 2
8
GATE OUT 3
9
NO CONNECTION
10
MUTE IN 4
11
MUTE IN 1
TO
12
MUTE IN 2
SCM410
13
MUTE IN 3
CIRCUIT
14
OVERRIDE IN 4
15
NO CONNECTION
10
Logic Function
Pin
No.
GATE OUT 1
6
GATE OUT 2
7
GATE OUT 3
8
GATE OUT 4
4
OVERRIDE IN 1
1
OVERRIDE IN 2
2
OVERRIDE IN 3
3
OVERRIDE IN 4
14
MUTE IN 1
11
MUTE IN 2
12
MUTE IN 3
13
MUTE IN 4
10
LOGIC GROUND
5
NO CONNECTION
15
NO CONNECTION
9