Test Results Are Inconsistent - Viavi T-BERD MTS 5800 Getting Started Manual

Appendix B Maintenance and Troubleshooting
Performing tests

Test results are inconsistent

Verify the following:
• Verify that your instrument is connected to the circuit properly for the test you are
running. For details, see
This is the primary reason for inconsistent test results.
• Verify that your transceivers and cables are good and are connected properly for
the test you are performing.
• Verify that you have inserted the correct transceiver for the circuit you are testing.
SFPs, SFP+, XFPs, QSFP+, and CFPs are designed to support different line
rates and interfaces.
• Verify that the correct timing source is selected on the Interface setup screen.
• Verify that the correct line rate for the interface is selected.
• If you are running SONET or SDH applications, verify that the correct mapping,
tributaries, and analysis rates are selected.
• If an object or person coming in contact with the test set causes a temporary burst
of errors to be recorded, the errors might have been caused by an ESD event.
The recorded errors can be cleared by pressing Test Restart. Please note that the
test set is fully compliant with IEC 61326-1 ESD requirements for industrial equip-
ment and has passed testing according to IEC 61000-4-2 using test limits of 4 kV/
8 kV contact/air and performance criterion B.
The best method of preventing ESD events is to use an ESD wrist strap and/or use a
grounding mat or table. Viavi recognizes that most field users will not have access to
these items at will and therefore cannot have an ideal, ESD-free environment.
In this case, Viavi offers the steps below to help reduce the chances of an ESD event
as much as possible.
a
b
c
d
e
Page 258
"Connecting your instrument to the circuit" on page 79
Zero Potential - Most importantly, make sure that you and the test set are at
Zero Potential by touching the metal frame of the AC mains power strip
before touching the unit both before and during the test.
Restricting movement – When achieving zero potential through the above
means is not practical, it is recommended to stand upright while using the test
set or otherwise minimize movement. Even when still, use of ESD-safe furni-
ture is recommended whenever possible.
Clothes - Make sure not to wear any clothing that builds excessive electrical
charge, such as a wool sweater.
Weather - Electrical storms can increase the risk of ESD events. Unless
absolutely necessary, try not to use the test set during an electrical storm.
Accessories - To help reduce ESD and help prevent other problems, it is also
a good idea to remove all jewelry.
T-BERD/MTS/SC Getting Started Guide
22046537, Rev. 016 March 2018