Studio Technologies 216 - Manual (Page 26)

Issue 1, July 2014 Model 216 User Guide
Page 26 Studio Technologies, Inc.
To make the process of connecting to the
Model 216’s headers a simple task an
interface cable kit, part number 31087,
is available from Studio Technologies.
Each kit includes five cable assemblies
and a length of heat-shrinkable tubing.
Each cable assembly consists of a mating
connector with three color-coded wires
attached. These wires, approximately 12
inches in length, allow convenient solder-
ing to a connector selected to be installed
in a spare location on the Model 216’s
back panel. For reference, the wire color
for pin 1 is gray, pin 2 is yellow, and pin 3
is blue.
The heat-shrinkable tubing is provided
so that the connector terminals or “solder
cups” can be insulated from each other.
It will also provide some strain relief to the
solder joints. Be certain to slip the desired
length of tubing over the wire prior to sol-
dering a connection! (If the writer had
a dollar for every time he forgot to put tub-
ing on a wire (or slip on a connector shell)
before making a solder connection….)
Most of the 3-position headers on the
Model 216’s main circuit board assembly
are located close to their related input or
output connectors. Others headers pro-
vide access to functions such as the relays
or the remote control inputs. For details on
the headers please refer to Appendix B at
the end of this guide.
Remote Control Connections
Provision has been made on the Model
216’s printed circuit board assembly to
allow external switches or contact closures
to control the status of the audio signal
sent to the main and talkback output
channels. Two 3-position headers provide
access to the circuitry associated with
the functions. Refer to Appendix B for
connection details.The input circuitry is
“active low,” with a 3.4 k ohm resistor con-
nected to +3.3 volts DC to act as a pull
up. A combination of resistors and capaci-
tors provide ESD protection.
Relay Contacts
The Model 216 provides two normally
open (not shorted) relay contacts for use
in specialized applications. One is as-
sociated with the main pushbutton and
the other with the talkback 1 pushbutton.
Whenever audio is being sent to the main
output channel relay contact 1 will close
(short). And whenever audio is being sent
to talkback output channel 1 relay contact
2 will close (short). The two relays operate
under software control and are always ac-
tive, whether or not connections are made
to them.
Some “head scratching” or “brainstorm-
ing” should lead to a number of interesting
ways to take advantage of the relay con-
tacts. Applications could include keying
wireless transmitters, activating “on-air”
lights, and muting loudspeaker systems.
To utilize the relay contacts does require
the talents of a qualified technician. This
is because the Model 216’s enclosure
must be disassembled and the desired
wiring scheme implemented. For detailed
information on interfacing with the relay
contacts refer to Appendix B at the end of
this guide.
Pushbutton Backlighting
From the factory, white LEDs are installed
in the pushbutton housings. These LEDs
provide illumination (“backlighting”) of the
pushbutton switches. This may prove use-
ful for applications where adequate room
lighting is not available. It’s important to
note that the pushbutton lighting does not