Testing a comtrol device – Comtrol Multiport Modems Windows 98 User Manual
Page 35
Comtrol Tools
35
Testing a Comtrol Device
If the COM port is available, a terminal window appears:
Note: Notice the
it is green and uppercase (
), the COM port internal loopback feature is
activated, and the data is returned by the COM port hardware. If this option
is deactivated, it is gray and lowercase (
), the internal loopback is
deactivated, and the data is sent out the COM port.
Testing a Comtrol
Device
The following procedure describes how to use two tests to check serial port
connections. These tests are:
•
Send Test Data - This test sends data out the transit line to the loopback
plug which has transmit and receive pins that send the data back through the
Receive line to the Test Terminal application. The Test Terminal displays the
data received in the terminal window for that port. The Send Test Data only
tests the transmit and receive signal lines and nothing else. The port window
displays the alphabet incrementing by one letter for each line of data received
until it reaches the uppercase letter Z and then it repeats until you stop the
test. If this test fails, it indicates the port is not working.
Note: You can run this test on RS-232 and RS-422 (or RS-485) ports.
•
Loopback Test - This test uses the Comtrol supplied loopback plug to test all
modem control signals (for example, RTS, DTR, CTS, DSR and CD) and the
Transmit and Receive signals on ports configured for RS232 use. The
Loopback test changes the state of the lines and looks for corresponding state
change. If it successfully recognizes all of these changes, the port passes the
test.
Note: You can run this test on RS-232 ports. This test will fail if the port is
configured for use as either RS-422 (or RS-485) because RS-422 (or RS-
485) does not have the modem control signals that are present in RS-232
that this test is designed for. This test cannot be used on RocketModem
products as there is no loopback plug for the phone port on the modem.
Use the following procedure to test the serial ports on the Comtrol device.
1.
If Test Terminal is not already running, start Test Terminal. See
on Page 34 for instructions.
2.
Place a loopback plug on the COM port you are testing. Make sure all
connectors are seated firmly and that the loop button is off.
Note: To build loopback plugs, see the latest Hardware Installation
documentation. See
Hardware Installation Documentation
for more information on the location of this document.