Hardware Problem 3
You suspect there is a faulty synchronous port.
Solutions:
The internal test program of the DEC MicroServer tests much of the circuitry
in the unit. However, it can only test a synchronous port when a loopback
connector is attached to it. If a port is faulty, the
DEC MicroServer detects communication errors when trying to use that port.
If you suspect that a port is faulty, do the following:
1.
Disconnect the DEC MicroServer from the power supply.
2.
Remove the cables from the synchronous port you want to test, and attach
the 50-way loopback connector (H3199) supplied with the DEC MicroServer
hardware.
3.
Power up the DEC MicroServer, and watch the display on the control
panel.
With the loopback connector attached, the internal test program can check
the port as well as the internal circuitry. If the display shows
d
, the
synchronous port might be faulty. For more information, see Installing the
DEC MicroServer. If the test program proceeds normally, it is likely that there
is no fault on that port. To perform any further fault isolation on the line, read
the information on loopback testing in Chapter 2.
One faulty port on the DEC MicroServer does not necessarily prevent you
from using the DECnet SNA Gateway for Synchronous Transport system. For
example, if you have a DEC MicroServer and you are using two lines only
at speeds less than 64K bits per second (bps), you can simply use one of the
two free ports instead of the faulty one. However, one faulty port on the DEC
MicroServer-SP does prevent you from using the DECnet SNA Gateway for
Synchronous Transport system. Read the configuration guidelines in Appendix
E to see which spare ports (if any) are available for your configuration.
Treat any reconfiguration that you make as temporary, and call Digital
Customer Service to arrange for the unit’s replacement.
1–8 Solving DECnet SNA Gateway for Synchronous Transport Problems
