Multi Tech Equipment MT5634ZBA-V-V92 manual Modem Does Not Respond to Commands

MultiModemZBA-V-V92 User Guide 8 Solving Problems

The Modem Does Not Respond to Commands

ÖMake sure the modem is plugged in and turned on. (See “None of the Indicators Light.”)

ÖMake sure you are issuing the modem commands from data communication software, either manually in terminal mode or automatically by configuring the software. (You cannot send commands to the modem from the DOS prompt.)

ÖMake sure you are in terminal mode in your data communication program, then type AT and press ENTER. If you get an OK response from your modem, your connections are good and the problem likely is in the connection setup in your communication software.

ÖTry resetting your modem by turning it off and on. If you are using DOS or Windows 3.1 communication software, make sure the initialization string includes &F as the first command, to cancel any “leftover’ command that could affect the modem’s operation.

ÖIf you don’t get an OK, the problem may still be in the communication software. Make sure you have done whatever is necessary in your software to make a port connection. Not all communication programs connect to the COM port automatically. Some connect when the software loads and remain connected until the program terminates. Others can disconnect without exiting the program. The modem’s TR indicator lights to show that the software has taken control of the modem through the COM port.

ÖYour communication software settings may not match the physical port the modem is connected to. The serial cable might be plugged into the wrong connector—check your computer documentation to make sure. Or you might have selected a COM port in your software other than the one the modem is physically connected to—compare the settings in your software to the physical connection.

ÖIf the modem is on, the cable is plugged into the correct port, the communication software is configured correctly, and you still don’t get an OK, the fault might be in the serial cable. Make sure it is firmly connected at both ends.

ÖIs this the first time you have used the cable? If so, it may not be wired correctly. Check the cable description on the packaging to make sure the cable is the right one for your computer.

ÖPeripheral expansion cards, such as sound and game cards, might include a serial port preconfigured as COM1 or COM2. The extra serial port, or the card itself, may use the same COM port, memory address, or interrupt request (IRQ) as your communication port. Be sure to disable any unused ports.

Windows 9x: Right-click on My Computer, select Properties from the menu, click on the Device Manager tab, double-click on Ports, then double-click on the communication port your modem is connected to. In the port’s Properties sheet, click on the Resources tab to see the port’s input/output range and interrupt request. If another device is using the same address range or IRQ, it appears in the Conflicting Device List. Uncheck Use automatic settings to change the port’s settings so they do not conflict with the other device, or select the port the conflicting device is on and change it instead. If you need to open your computer to change switches or jumpers on the conflicting device; refer to the device’s documentation.

Windows NT 4.0: To look for address or IRQ conflicts, click Start, Programs, Administrative Tools (Common), and Windows NT Diagnostics. In the Windows NT Diagnostics dialog box, click the Resources tab to see which input/output ranges and interrupt requests are in use. If you need to open your computer to change switches or jumpers on the conflicting device; refer to the device’s documentation.

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