Black Box MD885A-R3 Modem User Manual


 
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Modem 34336
Table D-1. Jumper Switch Functions.
JUMPER(S) Pins 1 and 2 connected Pins 2 and 3 connected
JP1 Frame and signal Frame and signal
ground connected ground not connected
JP2 -12/-24/-48 VDC operation
JP3, JP4 -12/-24/-48 VDC operation
(Set to same
position)
JP5, JP6 A/A1 control MI/MIC control
(Set to same
position)
JP7 Pin 25 used for analog Pin 25 used as test
loopback (input) mode indicator (output)
JP8 For factory use only. Do not change JP8 setting!
Factory settings are shown in bold face.
For each jumper, pin 1 is identified by a “1” printed on modem circuit board.
(The JP2 pin 1 label may be difficult to read; JP2 pin 1 is the pin closest to
the edge connector.)