SWP123 Presentation Switcher • Operation 3-5

4. Stop speaking into the microphone. The main program audio should
recover to the previous level after approximately two seconds. If not,
increase the threshold by turning the Talk Over Threshold Adjust pot
counterclockwise.

+24V Phantom Power switch

If a condenser microphone is used and power is required, set the +24V Phantom
Power switch on the back panel of the switcher to On.
Decoder Loop Function
For data projectors, plasma displays, and other displays on which the composite
video and S-video inputs do not work independently, the SWP123 is equipped
with a decoder loop function that converts all composite video signals to S-video.
This is accomplished by using an external Extron YCS Transcoder or a VYC
100N/P composite video to S-video decoder. Once the decoder loop is
configured and programmed, the following occurs when you select a composite
video input:
•The switcher automatically selects Input 4 in the S-video A/V group to enable
the loop.
•The Extron YCS Transcoder or VYC 100N/P composite video to S-video
decoder converts all composite video signals coming through the switcher
to S-video.

Wiring the decoder loop

1. Connect the output of the Composite Video A/V group to the composite
input of the transcoder or decoder.
2. Connect the S-video output of the transcoder or decoder to S-video input 4
of the SWP switcher.
3. Connect the S-video output of the SWP switcher to the S-video input of the
display device.
4. Activate the decoder loop using the correct RS-232 serial command (see
chapter 5) or the ICS100 Control Software (see chapter 4).
Figure 3-2 — Wiring the decoder loop
MIC INPUT
RX+
RX-
TX+
TX-
GND
RS422/485
LISTED
1T23
I.T.E.
C
RS232
+
-
+
R
L
-
+
-
+
R
L
-
L
R
L
R
L
R
INPUT 1
L
R
INPUT 2 INPUT 3
AUDIO [S-VIDEO]
INPUT 4
OUTPUT
+
-
+
R
L
-
L
R
L
R
L
R
INPUT 1
L
R
INPUT 2 INPUT 3
AUDIO [COMPOSITE]
COMPOSITE VIDEO
MADE IN U.S.A.
INPUT 4
INPUT 1 INPUT 2 INPUT 3 INPUT 4
OUTPUT
OUTPUT
S-VIDEO
INPUT 1 INPUT 2 INPUT 3 INPUT 4 OUTPUT
+
-
+
R
L
-
L
R
L
R
L
R
100-240V 0.4A 50/60Hz
MASTER
AUDIO
OUTPUT
INPUT 1
L
R
INPUT 2 INPUT 3
AUDIO [VGA]
INPUT 4
INPUT 4 OUTPUT INPUT 3
VGA
INPUT 2INPUT 1
OUTPUT
SERIAL
PORT SERIAL
FORMAT
SELECT
MADE IN
USA
FUSE: 1.6A 250V
TIME DELAY
+24V
PHANTOM
POWER
OFF
ON
+
TALK OVER
THRESHOLD
ADJUST
COMPOSITE VIDEO
INPUT 1 INPUT 2 INPUT 3 INPUT 4 OUTPUT
SWP123
ExtronYCS TranscoderComposite Video/S-Video TranscoderProjectorVCRs
COMPOSITE TO S-VIDEO
BUFFERED
LOOP-OUT
BUFFERED
LOOP-OUT
OUTPUTOUTPUT
S-VIDEO TO COMPOSITE
INPUT INPUT
PAL
9V
0.7A MAX.
NTSC
SWP123-2