QSC Q-SYS Core 110f Technical Notes

Technical Notes

Q-SYS Core 110f

Using the GPIO inputs and outputs

The Q-SYS Core 110f features General Purpose Input/Output (GPIO) connections that allow the core to interface with
miscellaneous outside devices, such as LED indicators, switches, relays, and potentiometers, and with custom or third­party controls. The GPIO allotment on the Core 110f totals 16 inputs and 16 outputs. Use Q-SYS Designer to select the
type of input or output and configure it. Each GPIO input and output is independent of the others.

Flanking each row of eight GPIO inputs and outputs is a +12 V DC terminal (up to 200 mA available on each, protected
by a self-resetting fuse) and a ground or reference terminal. This can be used for potentiomenters (input), relay coils and
LEDs (output), and other uses.

GPIO configurations

These are the various ways that GPIO inputs and outputs can be configured.

Input

Type

Digital Input (TTL 3.3 V)—The input is fed by a 3.3

V TTL digital source. The two states are logic high (1)
and logic low (0).

Contact Closure Input—This setting enables an in­ternal pull-up resistor, allowing actuation by a contact
closure to ground. This can be through a switch, set of
relay contacts, etc.

Potentiometer (10 kΩ, 12V)—In this setting, the
external potentiometer acts as a variable voltage
divider. The GPIO input reads the voltage delivered. The
ground terminal is the reference. The GPIO interprets
the voltage as a proprtion between the minimum and
maximum pot positions, with better resolution and
accuracy than the two-wire potentiometer configura­tion offers. This configuration requires calibration of
the pot’s minimum and maximum positions.

Conceptual schematic Control pins Notes

None

None Internal pull-up resistor

to +12 V. When contacts
are closed, GPIO In = 0V;
when open, GPIO In =
+12V.

Calibrate Maximum
Calibrate Minimum
Maximum Position
Minimum Position

Calibrate the minimum
and maximum positions of
the pot.

Rev. B, 14 November 2017

Input

Type

Potentiometer (2-wire)—In this setting, the external

potentiometer is connected merely as a rheostat—a
variable resistor. The internal pullup resistor is enabled,
so the variable resistor delivers a variable voltage to
the GPIO input; the GPIO circuitry interprets the voltage
as a proportion between minimum and maximum.
This configuration also requires calibration of the pot’s
minimum and maximum positions.

Analog Input (0–24V, low Z)—In this setting the
GPIO reads the positive analog voltage presented to its
input terminal.

Conceptual schematic Control pins Notes

Calibrate Maximum
Calibrate Minimum
Maximum Position
Minimum Position

Calibrate the minimum
and maximum positions of
the pot.

Output

Raw—Combines features of both analog and digital

inputs.
Digital Output (TTL 3.3 V)—The output feeds a 3.3 V

TTL digital input or its equivalent. The two states are
logic high (1) and logic low (0).

Open Collector (200 mA)—In this setting each output
can sink up to 200 mA of current, making it suitable to
actuate the low side of a relay (shown), LED, or other
device. A relay, for example, can be used to switch
higher levels of voltage or current.
CAUTION: The GPIO output is not fused. Current greater
than 200 mA can damage it.

Raw—Similar to the Digital Output setting, except it
offers an “invert”option.

Pullup enable See the tech note pertain-

Invert See the tech note pertain-

Application Examples

Shure MX396/C Microphone Button/Light Clockaudio CH32 Touch Sensitive Switch

Purpose: To convey switch actuations to the Core and turn the mic’s status
light either red or green (the LED cannot be turned off), as directed by the
Core’s GPIO output.

The mic receives phantom power from the Core 110f. The Core 110f can
accommodate as many as 16 MX396/C mics.

Purpose: To convey switch actuations to the Core and turn the LED ring of the
Clockaudio CH32 touch sensitive switch either red or green.

As many as three CH32 switches can share the same +12V and GND pins. A
Core 110f can only power as many as six CH32 switches; a suitable external
12V power supply, though, may allow as many as eight switches.

ing to the Raw input.

For 12 V relays or other
loads, use the +12 V
source provided. For high­er-voltage relays or loads,
use an external DC supply
(up to 24 V).

ing to the Raw output.

Set the GPIO input and output both to Digital.

Mic DIP switch settings:
1 Down
2 Either (does not matter)
3 Up

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Set GPIO input to Contact Closure. Set both GPIO outputs to Digital.