Manual

Model 216 User Guide Issue 5, November 2017
Studio Technologies, Inc. Page 29
Molex part number 08-50-0114 specifies
crimp terminals that are appropriate for
22 to 30 gauge wires. These terminals are
available worldwide from sources such as
Digi-Key (www.digikey.com).
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
soldering 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 contact closure inputs. For details
on the headers please refer to Appendix B
at the end of this guide.
Contact Closure Input
Connections
Provision has been made on the Model
216’s printed circuit board assembly to al-
low 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 connected to +3.3 volts
DC to act as a pull up. A combination of
resistors and capacitors provide ESD
protection.
Relay Contacts
The Model 216 provides two normally
open (not shorted) relay contacts for use in
specialized applications. One is associated
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 the
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 “brainstorming”
should lead to a number of interesting ways
to take advantage of the relay contacts.
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 disas-
sembled 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.