SERIES II INTELLIGENT DATA/FAX MODEMS

13)FAX (FX). This LED is lit when the modem is connected in FAX mode.

14)336+ (MD1640A) only: ERROR (ERR). When this LED is lit, either the leased line is down and the modem is in dial backup mode, or else the self-test has failed.

1.9Controls on PC Board

The Series II Modem is designed on a single printed circuit (PC) board. This board contains one 16-position DIP-Switch (numbered 1-16). The DIP-Switches are accessible through a cut-out on the side of the modem. There is also a knob which is used to adjust the speaker volume. This knob is accessible through the modem's rear panel.

The sixteen DIP-Switches control various modem options or set default values for Command Mode operation. There is a difference in how several of the switches operate depending on whether you are in syn- chronous or asynchronous mode. Refer to the switch label on the bottom of the Modem for an exact list of the switch functions in asynchronous and synchronous operation.

Chapter 9 of this manual also provides detailed instructions on configuring all of the Modem's PC board options.

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Black Box MD1641A, MD1640A manual Controls on PC Board