Studio Technologies 210 2008 - Manual (Page 32)

Issue 4, October 2008 Model 210 User Guide
Page 32 Studio Technologies, Inc.
P5: Main output, pin 1 shield, pin 2 high,
pin 3 low. Careful! Back-panel 3-pin male
XLR has pin 1 floating, pin 2 high, pin 3 low.
P6: Talkback output, pin 1 shield, pin 2
high, pin 3 low. Careful! Back-panel 3-pin
male XLR has pin 1 floating, pin 2 high,
pin 3 low.
P7: IFB input, pin 1 common, pin 2 DC with
channel 1 audio, pin 3 channel 2 audio.
Follows back-panel 3-pin female XLR pin
assignment.
P9: External 24 volt DC input, pin 1 com-
mon, pin 2 +24 volts, pin 3 not used. Back-
panel 2.1 x 5.5 mm jack has +24 volts on
center pin. Header P8 is used by the back-
panel 24 Vdc jack assembly and is electri-
cally in parallel with P9.
Additional functions can be accessed using
these 3-position headers:
P10: Auxiliary input 2, pin 1 common, pin 2
unbalanced audio, –10 dBu nominal.
P11: Auxiliary input 1, pin 1 common, pin 2
unbalanced audio, –10 dBu nominal.
P12: Pushbutton backlighting, pin 1 com-
mon, pin 2 button lamps, pin 3 current lim-
ited 24 volts from external 24 volt DC input.
P14: Remote switch connections, pin 1
common, pin 2 main output control, pin 3
talkback output audio.
Pushbutton Backlighting
For special applications, provision has been
made to allow illumination (“backlighting”)
of the two pushbutton switches. This may
prove useful for applications where ad-
equate room lighting is not available. It can
also serve in custom Model 210 configura-
tions. Note that this is an advanced feature,
intended only to be implemented by a
qualified technician.
From the outset several limitations must
be discussed. The first is that button
backlighting is not intended to serve tally
applications. (A common connection to
power both lamps is provided; indepen-
dent access to the lamp connections on
each button is not provided.) It is strictly
intended to provide a moderate amount
of illumination to the button’s clear lens
and associated labeling. The second
restriction is that power for the backlight-
ing function cannot be provided by the IFB
input—there is simply not enough cur-
rent available from a typical IFB circuit to
power the Model 210 and light the lamps.
However, power from the external 24 volt
DC source can be used. This requires that
this power source be connected whenever
backlighting is desired.
From the factory, lamps (“bulbs”) are
not installed in the pushbutton housings.
They are pluggable T-1 bi-pin type and
are simple to install. The mating socket
is accessed by removing the button’s
lens caps, graphic label, and back frosted
lens. Compatible incandescent lamps with
a nominal rating of 18 volts, 28 mA are
available from Studio Technologies (part
number 12030). Bulbs with other nominal
voltages should also be available from
electronics parts vendors. While compat-
ible LED-based lamps are probably also
available, incandescent lamps, when pow-
ered below their rated current and voltage,
can provide extremely long and reliable
operation.
A 3-position header connector, labeled
P12, is located on the Model 210’s main
printed circuit board. It provides access
to, and a means to power, the two lamps.
Pin 1 of the header is connected to the
common point of the Model 210’s circuitry,
which is also connected to one contact