Advanced Functions, Logic Connection Specifications

ADVANCED FUNCTIONS

The SCM810's Advanced Functions are recommended only for those who are technically knowledgeable and familiar with audio

electronics.

LOGIC CONNECTION SPECIFICATIONS

The logic functions of the SCM810 expand the mixer's range of installation and control 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 publication is available by contacting Shure's Applications Group.) The fol- lowing logic functions are available for each channel:

GATE OUT: Follows channel gating and goes to logic “low” (sinks current) when microphone is gated on. 500 mA of current sinking ability is provided (see Figure 10A).

+5 V		+5 V
10K		55K
	MUTE IN	TO
GATE	OR	TO
	OR	SCM810
	OVERRIDE	SCM810
OUT	OVERRIDE	CIRCUIT
OUT	IN	CIRCUIT
	IN
FROM
SCM810
CIRCUIT
LOGIC
GROUND
A		B

LOGIC EQUIVALENT CIRCUIT DIAGRAMS

FIGURE 10

MUTE IN: Applying logic “low” (from GATE OUT or a switch closure to logic ground) gates channel off (see Figure 10B). Channel output drops to -∞.

OVERRIDE IN: Applying logic “low” (from GATE OUT or a switch closure to logic ground) forces channel on (see Figure 10B). Factory setting pro- vides that when both Mute and Override are activated, Mute takes prece- dence (see Internal Modifications for Override precedence).

LOGIC GROUND: Logic ground is distinct from the SCM810 audio ground. Make all logic ground connections to this pin, including power supply ground of external logic circuitry. To avoid switching clicks, do not connect logic ground to audio, chassis or rack grounds.

Logic controls are accessed at the DB-25 multi-pin connector on the rear panel (Figure 11). The pin connections are given in the following table.

GATE 1

GATE 3

GATE 5

GATE 7

LOGIC

MUTE 1

MUTE 3

MUTE 5

MUTE 7 GROUND

O’RIDE 2

O’RIDE 4

O’RIDE 6

O’RIDE 8

MUTE 2		MUTE 4		MUTE 6		MUTE 8
GATE 2		GATE 4		GATE 6		GATE 8
O’RIDE 1	O’RIDE 3		O’RIDE 5		O’RIDE 7

LOGIC CONNECTOR

FIGURE 11

LOGIC CONNECTIONS

Logic Function	Input	Connector Pin No.
	Channel

GATE OUT1	1	1
GATE OUT 2	2	15
GATE OUT 3	3	4
GATE OUT 4	4	18
GATE OUT 5	5	7
GATE OUT 6	6	21
GATE OUT 7	7	10
GATE OUT 8	8	24

OVERRIDE IN 1	1	14
OVERRIDE IN 2	2	3
OVERRIDE IN 3	3	17
OVERRIDE IN 4	4	6
OVERRIDE IN 5	5	20
OVERRIDE IN 6	6	9
OVERRIDE IN 7	7	23
OVERRIDE IN 8	8	12

MUTE IN 1	1	2
MUTE IN 2	2	16
MUTE IN 3	3	5
MUTE IN 4	4	19
MUTE IN 5	5	8
MUTE IN 6	6	22
MUTE IN 7	7	11
MUTE IN 8	8	25

Logic Ground	all	13