External Control Input Connections
Page 29
Peavey Electronics Corporation
CV Return or “IN” Pins
2
4
6
8
10
12
14
16
Positive DC voltage
Even pin numbers
Control Voltage (CV) Input Ports
There are eight CV (control voltage) inputs on the MM
™
-8802. Each is identical in function and wiring, and each is represented
individually within the MediaMatrix software. These ports are 2-wire ports referenced to an internal ground. These connec-
tions are often the source of confusion to system designers, so please take note at the following information.
Refer to Fig. 4, Control Voltage Input Connections. The figure shows the row of eight 2-wire connectors and their associated
nomenclature. Each port has two pins. There is an even numbered pin and an odd numbered pin per port. Each even num-
bered pin (2,4,6, etc.) is internally wired to a positive DC voltage bus. This voltage is the basis for how the external analog con-
trols work with the software. The odd numbered pins (1,3,5, etc.) are "return" ports and each is independent of the other.
There are a total of eight return ports. To enable an external control, the supplied voltage must be returned to the odd num-
bered pins, referenced to the MM-8802’s internal ground.
What is very important to understand about the CV input port, is that this is NOT a dry contact configuration. It is not a
Form A closure where the contacts are expecting a change from an N.O. or N.C. state. With the CV ports on the MM-8802, the
fundamental operation is the return of a DC voltage to the port’s IN pin. The MM-8802 provides this voltage on every “+” pin,
allowing you to interconnect many different types of analog controls between the pins as active controls. The action of the cor-
responding software control is dependent on a return voltage on the IN pin. The following illustration shows the basic electri-
cal circuit for each of the MM-8802’s CV input ports. This illustration shows a single port, typical of all eight ports.
Fig. 5, Control Voltage (CV) Circuit
Fig. 4, Control Voltage (CV) Input Connections
Odd pin numbers
1
3
5
7
9
11
13
15
IN
Typical of 8 ports
Rear Panel
“CV In” Terminals
+
+15 V
+5 V
R
R
D
C
R
