HP AD278A and AD279A PCI Multiplexer Support Guide, Edition 2 - September 2006

Troubleshooting
Diagnostics Menu Selections
Chapter 2
26
Diagnostics Menu Selections
The Diagnostics menu seletion enables the user to perform the following tests:
• Loopback
•Send
Loopback
The loopback test is designed to test the primary components of the adapter cards and their functionality. At
any given time only one port can be tested. This simulates a loopback cable. Data is looped both towards the
computer and towards the terminal.
The program starts by writing a data pattern to the selected ports, and reading the data back and comparing
it to a pattern written out. At regular intervals, the program reports the number of characters transmitted
and received, and the errors encountered. The data is transmitted in an ascending pattern (from 1 decimal to
256 decimal). HP recommends that you disconnect any devices connected to ports being tested (in external
loopback mode).
To perform the external loopback test, attach a loop back connector that ties the port’s transmit and receive
signals together. As the control characters are being sent, any terminals or printers that are connected to the
selected ports during the external loopback test may hang. To exit this menu level, press the Esc key twice
To perform this test, select the Loopback sub-menu and press Enter.
Figure 2-4 shows the loopback test result.
Figure 2-4 Diagnostics loopback test
NOTE The Send sub-menu testing is not supported in this version.