Polycom MX392 - Manual (Page 28)

L
OGIC
O
UTPUT
Go to the Logic Output page of Conference Composer. If the LED IN wire is connected to Logic
Output pin 1, then you need to assign Pin 1 by left-clicking the desired pin in the DB-25 graphic.
The pin will turn color from gray to pink. Next, right-click on the pin and reverse the polarity. A
horizontal bar should appear under the pin number in the DB-25 graphic and under the pin number
under the Pin column:
Reversing the polarity is critical to proper operation. When S3 is in the ON position, the MX392
wants to see an Active Low signal (0V DC) from the Vortex Device in order to illuminate the LED.
By default, the EF Device has been designed to assume that an Active High signal (+5V DC) is
required to drive an LED. The MX392 uses the active low signal to use part of the phantom power
voltage to illuminate the LED. If you do not reverse the polarity, the LED will light up exactly the
opposite way you will have intended.
Next, right click in the A CTIVATED C OMMAND column for Logic Input 1 and select I NSERT , I NPUT , 1,
M UTE , O FF . Now, whenever the microphone is unmuted (Mute = False), the LED will illuminate on
the MX392.
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