Paradyne 3821PLUS manual Table C-2, Online Operation, Table C-3, Leased-Line Operation, Table C-4

COMSPHERE 3821Plus Modem

	Table C-2
	Online Operation
Symptom	Action
Data scrambled or	Verify that the character format (data bits, parity, and stop bits) is set to the same value in
unreadable	both modems.
Missing data during a	Verify that you are using the same method of flow control for both the modem and the DTE.
transfer	If using XON/XOFF flow control, verify that the modem's parity matches the DTE's parity.

	Table C-3
	Leased-Line Operation
Symptom	Action
Modems do not train-up on	Verify that the correct cabling is used for your application. Refer to Chapter 2 for modem
leased lines	installation instructions.
	Verify that one modem is configured for Answer mode and the other is configured for
	Originate mode.

	Table C-4
	Modem ± DTE Connection
Symptom	Action
Modem does not accept or	Verify that the cable between the Async port of the DTE and the modem is a standard
echo back AT commands	RS-232 cable. If the cable is bad, replace it. (Null modem cables, also known as crossover
	cables, do not work in this application.)
	Using the SDCP, reload the Async Dial factory configuration area to guarantee that all
	configuration options are returned to their proper setting.
	If an SDCP is not available, use the AT command recovery technique in Chapter 4.
Modem does not accept or	Make sure that all AT commands are terminated with a carriage return.
echo back AT commands	Verify that the DTE has a valid character format. Valid format consists of 8 data bits with no
	parity or 7 data bits with even, odd, mark or space parity.
	Verify that the DTE's data rate is set to a level supported by the modem
	(115,200 bps±300 bps).
	If using a PC, verify that the modem is attached to the correct communications port.

C-2 January 1999 3821-A2-GB20-40