TIA Category 6A test limits - please read carefully
The correct limits/formulae for Category 6A patch cords are contained within in ANSI/TIA-568-C.2-2 (2014), not ANSI/TIA-568-C.2 (2009). The limits found in ANSI/TIA-568-C.2 were based on the use of a compliant TIA patch cord jack. Such a jack does not exist for patch cord certification. However, Optical Cable Corporation (OCC) did develop a jack for the certification of Category 6A patch cords in accordance with ISO/IEC 11801 and IEC 61935-2. A proposal was made in TIA to allow the use of the ISO/IEC Category 6A patch cord jack for the certification of TIA Category 6A cords. The proposal was accepted and implemented in addendum ANSI/TIA-568-C.2-2, resulting in a new set of test limits. The addendum took the existing formulae found in ANSI/TIA-568-C.2 and replaced the TIA patch cord jack with the ISO/IEC jack performance requirement.
Failing to follow addendum ANSI/TIA-568-C.2-2 will result in a relaxed test limit. Let's compare the Near End Crosstalk (NEXT) test limits for a 2 m Category 6A patch cord @ 500 MHz:
ANSI/TIA-568-C.2, August 11th, 2009 = 28.4 dB
ANSI/TIA-568-C.2-2, November 7th, 2014 = 31.0 dB
We have been made aware that some non-Fluke Networks test stations/testers are using the incorrect ANSI/TIA-568-C.2 test limits for the certification of TIA Category 6A patch cords. You are encouraged to check your test station/tester limits against ANSI/TIA-568-C.2-2.
Looking to ANSI/TIA-568-C.2-2, which can be purchased from www.tiaonline.org, we find:
This Addendum specifies requirements for an alternative category 6A patch cord test head and provides guidelines for how to calculate requirements for category 6A cords when this patch cord test head is used. This Addendum is only applicable to category 6A patch cords according to ANSI/TIA-568-C.2.
The modular plug cord test limits shall be calculated using the connector contribution corresponding to the NEXT limits used for test head qualification. When the alternative test head is used, the NEXT loss requirement for category 6A cords shall be calculated according to ANSI/TIA-568-C.2 clause 6.9.2 equation 28, and the values provided by table 1 shall be used for term NEXTconn_spec in ANSI/TIA-568-C.2 clause 6.9.2 equation 29.
Table 1 - Alternative test head NEXT loss requirements
To ensure the correct use of the formulae, ANSI/TIA-568-C.2-2 provides an informational table of NEXT values in section 4.2, shown below:
Table 3 - Minimum category 6A work area, equipment, and patch cord NEXT Loss when using alternative test head
Author: Adrian Young/FlukeNetworks
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