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SERIES II INTELLIGENT DATA/FAX MODEMS
1.7 Power
Power is supplied through an AC power transformer terminated with a
standard two-prong plug. The transformer supplies low voltage AC to
the modem, and plugs into any conventional 115 volt AC, 60 Hz, two-
prong power outlet. The power transformer supplied with the modem
is the only one that should be used. Use of any other transformer could
cause damage to the modem. A Power On/Off switch is located on the
back of the modem.
1.8 Modem LED Indicators
The Series II Modem has fourteen diagnostic LED indicators. They are:
Figure 1-1. LED Displays of the 336 (MD1641A, top)
and 336+ (MD1640A, bottom)
1) Transmit (Send) Data (SD). This LED blinks when data is being
transmitted, on for a space, off for a mark. The state of this LED
matches the TD circuit on Pin 2 of the RS-232C/V.24 interface.
2) Receive Data (RD). This LED blinks when data is being received,
on for a space, off for a mark. The state of this LED matches that of
the RD circuit on Pin 3 of the RS-232C/V.24 interface.
3) Carrier Detect (CD). This LED is lit when a valid carrier tone
has been detected.
