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

Page 130
Image 130
Paradyne 3821PLUS manual Table C-2, Online Operation, Table C-3, Leased-Line Operation, Table C-4, Modem ± DTE Connection