RIO Remote I/O System User Guide
SCO OpenServer 5 troubleshooting
Page 284
9. You can now select and run the type of test you want using the Online Diagnostics menu.
See one of the options listed in the next table for further details;
Test To run this test click on For details of how to run this test
see...
Send data to port Send data to port Performing the send data to
port test on page 285.
External loopback Perform loopback test on port Performing the loopback test
on a port on page 287.