SERIES II INTELLIGENT DATA/FAX MODEMS

FRONT

LEDs

Voice/Data

switch with

Answ/Orig

Speaker

16-position DIP switch

 

 

 

 

 

 

 

 

 

OPEN

 

 

 

 

 

 

 

 

 

 

 

OPEN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

2

 

3

 

4

 

5

 

6

 

7

 

8

 

9 10 11 12

 

13 14 15 16

Power switch

Power jack

RS/232/V.24 connector

Volume knob Leased-ine jack

Dialup jack

Phone jack

REAR

Figure 9-2. Series II Modem 336+ (MD1640A) PC Board

9.2 DIP-Switch Option Settings

Switch #1

Forced DTR -- "DTR"

(Asynchronous/Synchronous Mode/Leased Line/Dial-Up)

The Series II Modem must have a high DTR signal in order to operate. DTR is provided to the modem by the terminal or computer to which it is attached, through pin 20 of the RS-232C/V.24 interface. If your terminal or computer is not providing DTR to the modem, you can force the DTR signal high with DIP-Switch #1.

DTR function normally DTR forced On Factory Default Setting

=Switch #1 UP

=Switch #1 DOWN

=UP

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Image 129
Black Box MD1641A manual DIP-Switch Option Settings, Series II Modem 336+ MD1640A PC Board