Black Box MD1641A, MD1640A manual 126

SERIES II INTELLIGENT DATA/FAX MODEMS

in Figure 8-6), the Local Analog Loopback Test should be performed on both the remote and local modems. If that test is successful, the problem may be the phone lines.

First make certain that you are set up for Synchronous operation by placing DIP-Switch #12 in the UP position. To initiate the Digital Loopback Test (remote/automatic), DIP-Switch #9 must be in the DOWN position, and the Answer/Originate switch (front of the modem) must be toggled to the UP position. Once you receive an OK message from your modem (if responses are enabled), the local modem is placed in Digital Loopback mode. To exit the Digital Loopback Test (remote/automatic), toggle the front panel Answ/Orig switch to the Answer position.

Computer or							Computer or
								Terminal
Terminal
			Local Series		Local Series
				II Modem		II Modem
	UUUUU	digital analog			digital analog
	UUUUU

Type ATU0 or ATU1; hit ENTER

Figure 8-7. Synchronous Mode Digital Loopback Test

(remote/automatic)

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