APPENDIX D. PROBLEMS AND SOLUTIONS You may occasionally encounter one of the problems listed here. They are divided into two categories: before and during the exchange of data over the phone link. Before the Modems Connect Your modem . . . Doesn't answer the phone or go off hook to dial a number Review the quick configuration guide or your software manual to see what Data Terminal Ready (DTR) operations your software requires. Then check to see if DIP switch 1 is set correctly. Doesn't respond OK when you type AT 1.Make sure you're typing in either upper case or lower case letters, not a combination, and that you press the Enter key. 2.Make sure your computer is in Terminal mode. This is a communications software function. See Testing the Installation in Chapter 2. 3.Check to see that your software is set to the correct bit rate and word length (7 bits with or without a parity bit, or 8 bits and no parity). Also make sure your software is set to the correct communications (serial) port, as determined in the setup instructions in Chapter 2, under Selecting a Serial Port. 4.Check that DIP switch 8 is DOWN, for command set recognition. If the switch is UP, set it DOWN and try typing AT again. 5.Check that DIP switch 3 is DOWN, for result code display, and that DIP switch 2 is UP, for verbal result codes. If not, change the switch(es) and type ATZ . Or type whichever of these commands is needed. ATQ0 (to enable result codes) ATV1 (to display verbal result codes) 6.Review the quick configuration guide that came with the modem or your communications software manual to see what Carrier Detect (CD) operations your software requires. Then check to see if DIP switch 6 is set correctly. Displays double characters Both your modem and software's local echo are on. You can turn your software's local echo off, or turn the modem's echo off by either resetting DIP switch 4 and sending the modem the ATZ command, or by sending the modem the ATE0 command. Your computer . . . Reacts as though a data link has been established, but no call has been received Review the quick configuration guide that came with the modem or your communications software manual to see what Carrier Detect (CD) operations are required. Then check to see if DIP switch 6 is set correctly. When the modem is in Answer mode, acts as if a Carriage Return has been entered, but nothing has been typed at the keyboard Your software may be misreading signals from the modem as it automatically sends a Carriage Return and Line Feed before and after the RING and CONNECT messages. Sending the Quiet Mode command, ATQ1 , should solve the problem. Both modems . . . Exchange carrier signals, but fail to establish a communications link 1.If you have a fax modem, make sure you are in the correct mode for the call you are receiving. The modem must be in data mode to receive a data call, and in fax mode to receive a fax call. See Fax Operations in Appendix E for information on switching between fax and data modes. 2.Check to make sure that you've set your software to the same word length, parity and number of Stop bits required by the remote computer and, if your modem is dialing out, that your software is set to a bit (or baud) rate equal to or higher than that of the remote modem. 3.Make sure the modem at the other end of the line is V.32 bis-compatible at 14.4K, 12K, 9600, 7200 or 4800 bps, V.32-compatible at 9600 bps, V.22 bis- compatible at 2400 bps, Bell 212A- compatible at 1200 bps, or Bell 103- compatible at 300 bps. These are the common signaling standards for full duplex dial-up network transmission in the U.S. 4.Make sure your modem's link rate setting, &Nn, is correct for the call. If the link rate is locked at a speed (&N1O&N8) different from the calling modem's, the Sportster hangs up. The factory setting of &N0, variable link operations, allows the two modems to negotiate the highest possible link rate. 5.If these steps fail to correct the problem, it's likely that the quality of the phone connection is poor and that the other modem is missing the signals your modem is transmitting. The variable quality of phone line connections may be due to any number of conditions in the phone service's equipment or the current environment. Try several calls, and if you still can't get through, try calling an other modem. If the second modem accepts your call, the problem may lie with the modem you first tried to call. During Data Transfer Your screen displays . . . Only brackets Check to make sure that your communications software is set to the same bit rate (or higher) as that of the remote modem, and that both your software and the remote system are set to the same word length, parity and number of Stop bits. If the settings are correct, the problem may be with the phone line. Try the following measures. 1.Place the call again. The phone company routes even local calls differently each time you call. 2.Call a different modem to see if the problem persists. The problem may be with the modem you first tried to call. Random or garbage characters Check to make sure that your communications software is set to the same bit rate (or higher) as that of the remote modem, and that both your software and the remote system are set to the same word length, parity and number of Stop bits. If the settings are correct, the problem may be with the phone line. If the modem is set to a fixed serial port rate (&B1) and your software is fixed at 19.2K, 38.4K, or 57.6K bps, the reason may be one of the following. 1.If you use memory-resident programs (TSRs), they may be interfering. Try disabling them before you run your communications software. The same is true of disk-caching programs. 2.Check to see that your software and the modem are set for the same kind of flow control, either hardware or software. Some communications programs also require that you dis able the kind you are not using. Double characters Your modem's online local echo is on and the remote computer is also echoing. There are two ways to handle this: one is to terminate the call, hang up, turn off the online echo (ATF1) when the modem is in Command mode, and call again. This way you will not lose any data. The second, riskier way is to force the modem into Online-Command mode by sending the escape code and to send the modem the ATF1 O command. The command turns off the online echo and returns the modem online. Use this second method only if the remote system and your modem are not in the middle of data transfer. IF YOU STILL HAVE PROBLEMS The problems described above are by far the most common ones that users encounter. If the suggestions we've given don't clear up your difficulties, try the following. 1.Review the manual carefully to see if you've missed something. 2.Call or visit your dealer. Chances are your dealer will be able to give you the assistance you need. This is much more efficient and time-saving than returning the modem to USRobotics. 3.If your dealer can't clear up your difficulties, call the USRobotics Technical Support Department at 800- 982-5151 Our Service Representatives will be happy to give you assistance over the phone Monday through Friday from 7:30 a.m. to 6 p.m. (Central Time Zone). If you prefer, you can contact us by fax at 708-982-0823. 4.If it is necessary to return the modem for service, the Service Representative you talk to will give you a Return Materials Authorization (RMA) number. If you do return the modem to us, please use the following procedures. a.Ship the unit, postage paid, in its original container. If the original container is not available, pack the modem carefully in a strong box of corrugated card board with plenty of packing material. b.Be sure to include your RMA number inside the package, along with your name and address. Put your return address and your RMA number on the shipping label as well. Modems without an RMA number will not be accepted. c.Ship the well-packed modem to the following address. Technical Support Department U.S. Robotics, Inc. 8100 North McCormick Boulevard Skokie, Illinois 60076-2999 d.Please note that USRobotics will not accept packages sent COD, so be sure to send the modem postage- paid. e.USRobotics will repair your modem and return it to you via United Parcel Service.