EMS Technologies Canada Ltd. HSD-400 Manuale Utente

This section provides basic information required for technical personnel to isolate faults 
in HSD-400 terminals. Where needed, refer to other sections of this manual (which contain 
important information to aid in understanding the functionality of the terminal) for additional 
information. 

Fault isolation procedures are usually conducted on equipment that falls within one of the 
following categories:

•

Terminals that have failed to pass operational and installation verification 
procedures

•

Terminals that have failed during service

•

Terminals repaired and returned to service

Maintenance reports are helpful in troubleshooting the HSD-400 terminal. Capturing 
maintenance port information from the HSD-400 terminal and forwarding the file to EMS 
SATCOM technical support staff will assist in troubleshooting suspected HSD system 
problems. Instructions on how to activate and save "reports" information is provided in the 
next section, Activating and Saving a Diagnostic "Reports" File.

No dial tone heard in 
handset

-

Activate report 21. • Confirm ISDN lines are 

wired correctly.

• Verify handset connection is 

secure.

• Wait a few minutes for the 

system to warm-up, then 
log-on and try your call 
again.

• Check that IRS data is 

available.

• Verify that the terminal has 

completed beam 
registration.

Call drops after 
successful 
connection

If the RF signal fades 
significantly (during a 
call) the connection may 
drop

Note: A sudden, severe 
aircraft banking angle 
may obstruct the signal 
long enough (>15 sec.)

Activate reports 21 
and 23

• Check signal strength 

 

(C/No greater than or equal 
to 50 dB). 

• Ensure there is a clear, 

unobstructed, line of sight to 
the satellite.

• Select an alternate satellite 

or beam and try your call 
again (Note: works if you are 
located where more than 
one beam overlaps or 
satellite is in view.)