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Make sure that you have installed and configured the latest driver.
Reboot the system with the bootable diagnostics to verify that it is not a hardware problem.
If you have a spare RocketModem IV try replacing the adapter.
For additional troubleshooting, you can refer to one of the following:
If using a device driver for a Microsoft system, you can check the following:
If using an in-house application, verify that you are addressing the port correctly. In many applications, device names above COM9 require the prefix \\.\ in order to be recognized. For example, to reference COM20, use \\.\COM20 as the file or port name.
Verify that the RocketModem IV has installed by checking the Device Manager to verify that the RocketModem IV displays.
After driver installation, if a port does not open; open the Device Manager, go to Ports COM&LPT, right-click on the yellow exclamation mark on the port, and click Update Driver.
You can open the Device Manager and enable the Verbose Event Log feature under the Options tab and then reboot the system.
You can install the Comtrol Utility, which includes Test Terminal for troubleshooting communications on a port-by-port basis and Port Monitor to check for errors, modem control, status signals, raw byte input and output counts.
You can use the Test Terminal procedure below or the Port Monitor (PMon2) and Test Terminal (WCom2) User Guide, which provides procedures for using both Test Terminal and Port Monitor to test ports and communications.
The following provides background information about the two tests procedures discussed for Test Terminal (Comtrol Utility).
Optionally, you can use the Port Monitor (PMon2) and Test Terminal (WCom2) User Guide, which provides procedures for using both Test Terminal and Port Monitor to test ports and communications.
Send and Receive Test Data: This sends data out the transmit line to the loopback plug, which has the transmit and receive pins connected thus sending the data back through the Rx line to Test Terminal, which then displays the received data in the terminal window for that port. This test is only testing the Tx and Rx signal lines and nothing else. This test works in either RS-232 or RS-422 modes as both modes have transmit and receive capability. A failure in this test will essentially prevent the port from working in any manner.
Loopback Test: This tests all of the modem control signals such as RTS, DTR, CTS, DSR, CD, and RI along with the Tx and Rx signals. When a signal is made HI in one line the corresponding signal line indicates this. The Loopback Test changes the state of the lines and looks for the corresponding state change. If it successfully recognizes all of these changes, the port passes.
A failure on this test is not necessarily critical as it will depend on what is connected and how many signal lines are in use. For example, if you are using RS-232 in 3-wire mode (Transmit, Receive and Ground) a failure will cause no discernible issue since the other signals are not being used. If the port is configured for use as either RS-422 or RS-485 this test will fail and is expected to fail since RS-422 and RS-485 do not have the modem control signals that are present in RS-232 for which this test is designed.
The following procedure shows how to use Test Terminal to send and receive test data to the serial ports and run a loopback test.
Stop all applications that may be accessing the ports such as RAS, RRAS, or any faxing or production software.
See the appropriate help systems or manuals for instructions on stopping these services or applications. If another application is controlling the port, then Test Terminal will be unable to open the port and an error message will be shown.
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From the Start menu, click Programs > Comtrol > Utilities > Test Terminal (WCOM2).
Click File > Open Port and the appropriate port (or ports) from the Open Ports drop list.
Install the loopback plug onto the port (or ports) that you want to test.
Click Port > Send and Receive Test Data.
You should see the alphabet scrolling across the port. If so, then the port installed properly and is operational.
Click Port > Send and Receive Test Data to stop the scrolling data.
Click Port > Loopback Test.
This is a pass fail test and will take a second or two to complete. Repeat for each port that needs testing.
The loopback test tests the modem control (hardware handshaking) signals. It only has meaning in RS-232 mode on serial connector interfaces with full RS-232 signals. If performed under the following conditions, the test will always fail because full modem control signals are not present:
RS-422
RS-485
RJ11 connectors
Close Test Terminal
If both of these tests successfully complete, then the port is operational as expected.
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You can use the following subsections to test the serial ports on a Linux system.
Comtrol has available lcom(1), which is a multiport serial I/O test program. You can use lcom in test mode to send test data to any serial port.
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The following examples use ports ttyR0 and ttyR1. You may need to substitute the port numbers that you will be testing.
Hardware Type | Port Nomenclature | |
---|---|---|
| ttyRx |
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You can also refer to the procedures below to check the ports:
Use the Testing with minicom document to test the serial ports
You can transfer a file using the following information. The default settings are 9600, 8, n, 1, and no parity. To send a file you can redirect output to a device, where x is 0 through 7, for example:
cat /etc/inittab > /dev/ttyR0
Sends the contents of the /etc/inittab file to the ttyR0 device at 9600 baud, 8, n, 1, and no parity.
Use the following information if you need assistance changing or viewing the baud rate settings.
To change the baud rate, use the following example, which changes the baud rate to 19200, where x is 0 through 7.
stty 19200 </dev/ttyR0
To view the current serial port settings for ttyR0, enter:
stty -a </dev/ttyR0
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Add the appropriate line or lines to the /etc/inittab file then restart.
Some distributions use the agetty command and other distributions use getty. Check the documentation for your Linux distribution if you are unsure.
Terminal Example:
T0:23:respawn:/sbin/agetty -L ttyR0 57600 vt100
Modem Example:
T1:23:respawn:+/sbin/mgetty -m ‘"" AT&F OK’ -D -x9 -s 115200 ttyR0
If necessary, see the manual pages for more information on mgetty.
You can also use minicom to test the serial ports, which is shipped with most Linux operating systems. A Comtrol document is available for using minicom.
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