Black Box MD1641A, MD1640A manual Power, Modem LED Indicators

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:

Answ

SD

RD

CD

33.6

24.0

19.2

14.4

96

24

OH

TR

EC

FX

Orig

Voice/

Send

Rcv

Carr

33.6K

24.0K

19.2K

14.4K

9600

2400

Off Hk

Rdy

V.42

Fax

Data

Answ

SD

RD

CD

33.6

24.0

19.2

14.4

96

24

OH

TR

EC

FX

ERR

Orig

Voice/

Send

Rcv

Carr

33.6K

24.0K

19.2K

14.4K

9600

2400

Off Hk

Rdy

V.42

Fax

Error

Data

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.

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