TEK-IRIGB-MNL-v2-042016
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© 2016 by Tekron International Limited. All Rights Reserved. All trademarks are the property of their respective holders. The
information in this document is provided for informational use only and is subject to change. For further information or support, go to
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Polarity Inverted
Figure 27: Polarity Inverted- Help Screens 1, 2, 3 & 4
This help screen prompts the user to check the probes are connected to the IRIG-B signal with the
correct polarity and explains why RS-232 IRIG-B normally is reported as inverted. See the
Troubleshooting section below for more help on Inverted Polarity.
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TROUBLESHOOTING GUIDE
1.
No Signal Detected
a.
Confirm the source of the IRIG-B signal is configured to output IRIG-B and that it is in
operation.
b.
For copper IRIG-B, check the probes are making secure contact with the line. Some
pressure may be required to get good signal detection. The IRIG-B Analyzer is able to
measure IRIG-B signals down to 2V peak to peak.
c.
For fiber IRIG-B, check the fiber connectors are properly inserted into the fiber socket
and ensure the fiber signal being measured is using the correct standard (i.e. 820nm
λ
multi-mode fiber). Check the fiber patch cable being used supports 830nm
λ
multi-
mode signals.
2.
Blank Screen when powered up
a.
Check battery condition, replace with fresh batteries if needed. Check they are
installed in the IRIG-B Analyzer with the correct polarity.
b.
If the problem persists, contact Tekron at: [email protected]
3.
Measured IRIG-B Signal Reported as Inverted
The IRIG-B Analyzer is optimized to measure electrical IRIG-B signals where the IRIG-B logic 1
level is more positive than the logic low level, (for example in TTL levels Logic 1 is nominally
+5v and Logic 0 is 0v).
The RS-232 standard however has the logic levels reversed so that logic 1 is a negative voltage and a
logic 0 is a positive voltage. As a consequence, when measuring RS-232 signals with the IRIG-B
analyzer, it is normal that the polarity is reported as inverted.
RS-422 and RS-485 IRIG-B signals are balanced signals so when measuring these with the IRIG-B
analyzer care should be taken to measure the signal between the two signal wires and not from one
