Polycom MX392 manual Logic Output

Repeat the process for each microphone that is connected to the Logic Input port. If you are successful, you should see this on the screen (the screenshot is from a Vortex EF2241):

Make sure that the physical wiring works by pressing the membrane switch. You should see the LED above the pin assignment lit in green:

LOGIC OUTPUT

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 Vortex 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.

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