Performance specification for the Fluke DSP Fluke Corporation

Transcription

1 Performance specification for the Fluke Fluke Corporation 1. Summary This document contains the performance specifications in terms of requirements per draft TIA and IEC specifications. Since requirements are subject to change, the performance is as explicitly stated in this document. The exceeds the currently specified performance parameters for per the consensus proposal by all field tester manufacturers as represented in this document. Refer to ACC_MOD.PDF document, which can be found in the Expert Information about copper cabling portion of the Cable and Fiber section of the Fluke WEB site for detailed information on the TIA and IEC guidelines to determine measurement accuracy. TIA and IEC guidelines also require that all results are marked with an asterisk ( * ) when the result is closer to the pass/fail limit than the accuracy of the measurement. Section 2 describes in detail how the uncertainty bands around the pass/fail limit are determined. Section 3 describes the formal performance requirements per TIA and IEC guidelines for reference purposes and section 4 describes the resulting measurement accuracy per these guidelines. 2. Uncertainty bands of the The substantially exceeds the measurement accuracy requirements per draft proposals. Table 1 shows the uncertainty bands for the. Accuracy at intermediate frequencies is determined by linear interpolation. These accuracy figures are applicable to the basic link test configuration. Insertion Loss (attenuation) Near-End Crosstalk (PP & PS) Attenuation-to-Crosstalk Ratio (PP & PS) Equal Far End Crosstalk (PP & PS) Return Loss (3 rule is applicable) Category 5E (± ) 1 MHz 100 MHz 1 MHz 100 MHz 1 MHz 100 MHz 1 MHz 50 MHz 100 MHz 1 MHz 100 MHz Category 6 (± ) 1 MHz 250 MHz 1 MHz 250 MHz 1 MHz 250 MHz 1 MHz 50 MHz 250 MHz 1 MHz 100 MHz Table 1: Baseline uncertainty bands for the Supporting the uncertainty bands in table 1, figure 1 depicts a conservative estimate of practical measurement accuracy. Performance specification for the Fluke 1 acc_dsp-.doc 03/08/00 3:31 PM

2 Baseline measurement accuracy at TIA / ISO/IEC Class E channel limits. Computed using the worst case of each performance parameter specified for field testers 5.0 Accuracy in Insertion loss NEXT ELFEXT Return Loss Frequency in MHz Figure 1: Typical measurement accuracy of the. This result is obtained under the following conditions: For each performance parameter (for example source/load return loss, residual NEXT, etc.), at every frequency the worst result for any wire pair or wire-pair combination is obtained. The values of the worst case wire pair or wire pair combinations are substituted in the accuracy equation per TIA and IEC guidelines. Worst case assumptions for link performance that affect measurement accuracy are used. These include the assumptions for link return loss, common-mode-to-differential-mode gain, differential-to-common-mode gain. As a reference, the measurement accuracy resulting from minimum performance requirements for field testers is as shown in figure Baseline measurement accuracy at TIA / ISO/IEC Class E limits. Computed from minimum requirements. Measurement Accuracy in Insertion loss NEXT ELFEXT Return loss Frequency in MHz FIgure 2: Measurement accuracy based on worst case performance requirements. Figure 2 illustrates that the substantially exceeds minimum requirements, even with numerous worst case assumptions. Performance specification for the Fluke 2 acc_dsp-.doc 03/08/00 3:31 PM

3 3. accuracy performance specifications based on TIA and IEC guidelines The meets and exceeds each performance parameter specification individually. The computed accuracy from worst case observed performance parameters and worst case assumptions for the link under test is as shown in section 2. This section describes the current TIA and IEC requirements for a compliant tester. Table 2 contains the performance requirements for length, propagation delay and delay skew. They are applicable to any test configuration as well as IIE and compliant field testers. Performance Parameter Length Propagation Delay Delay Skew Accuracy ± 1 m ± 4 % ± 5 ns ± 4 % ± 10 ns Table 2 - Length, propagation delay, and delay skew accuracy specifications Table 3 contains the performance requirements related to attenuation, NEXT, PS NEXT, ELFEXT, PS ELFEXT and return loss for field testers. These match exactly what is currently contained in a consensus proposal for compliant testers as of this date, except for the following: The residual NEXT performance of the "with adapter" test configuration is identical to the residual NEXT of the baseline configuration (results in much better NEXT and PS NEXT accuracy). The directivity, source match and return loss of termination are specified tighter at low frequencies. This reflects the impact of the "3 rule" for return loss (pass/fail for return loss does not apply when the attenuation of the link under test is below 3 ). This means that a return loss pass/fail can never occur below approx. 2.2 MHz (with a maximum length link), and in the far majority of cases is at higher frequencies. Practically, the measurement accuracy is approximately constant over the entire frequency range. The requirements in accolades { } indicates the requirements in the current consensus proposal for performance. Explanation of notes are in table 3. The resulting estimated measurement accuracy at the channel test limits for TIA Category 6 or ISO/IEC are shown in table 4 (baseline accuracy) and table 5 ("with adapter" accuracy). The typical performance of the is well within the guaranteed specifications. Performance specification for the Fluke 3 acc_dsp-.doc 03/08/00 3:31 PM

4 Parameter Baseline "With adapter" Dynamic Accuracy NEXT ± 0.75 Note 1 ± 0.75 Note 1 Dynamic Accuracy ELFEXT ± 1.0 Note 1,2 ± 1.0 Note 1,2 Source/load return loss log f / log( f /100) 20 max 20 max Random Noise Floor log( f /100) log( f /100) 85 max 85 max Residual NEXT log( f /100) log( f /100) { log( f /100)} Residual FEXT log( f /100) log( f /100) Output Signal Balance log( f /100) log( f /100) Common Mode Rejection log( f /100) log( f /100) Tracking ± 0.5 Note 1,2 Note 5,6 Note 5 Directivity 27 7 log( f /100) log( f /100) 35 max typical 25 max 30 guaranteed Source Match Note 5, log( f /100) Note log( f /100) 25 max typical 20 guaranteed 20 max Return loss of Termination Note 5, log( f /100) Note log( f /100) 30 max typical 25 guaranteed 25 max Notes are explained in table 4. Table 3: Accuracy parameter specifications of the Note Description 1 Verification of dynamic accuracy is required up to the maximum values for NEXT and FEXT of a compliant link The dynamic accuracy is based on dynamic accuracy performance for attenuation and NEXT, and is assumed to combine the dynamic accuracy for ELFEXT as specified. 3 Performance verification of residual NEXT and residual FEXT is up to 85 maximum. It is assumed that the frequency response changes at a rate of 20 /decade. 4 Performance verification of Output Signal Balance and Common Mode Rejection is up to 60 maximum. It is assumed that the frequency response changes at a rate of 20 /decade. 5 Performance of directivity, source match and return loss of termination assume that requirements do not extend to lower frequencies where the measured attenuation of the link is below 3. Practically, the lower limit of return loss pass/fail is approx. 2.1 MHz 6 Shown is a maximum limit representing typical performance at room temperature. The guaranteed limit is valid for the whole operating temperature range. Table 4: Explanation of notes Performance specification for the Fluke 4 acc_dsp-.doc 03/08/00 3:31 PM

5 4. Overview of computed measurement accuracies per TIA and IEC Guidelines. Attenuation NA 2.1 NEXT NA 2.6 PS NEXT NA 2.7 ELFEXT NA 3.8 PS ELFEXT NA 4.0 Return Loss NA NA NA 2.2 Table 5: Baseline accuracy of the at draft TIA Category 5E/6 or ISO/IEC Class D/E channel limits and using the3 rule for return loss. Attenuation NA 2.5 NEXT NA 3.5 PS NEXT NA 3.5 ELFEXT NA 5.0 PS ELFEXT NA 5.3 Return Loss NA NA NA 3.9 Table 6: Accuracy "with adapter" of the at draft TIA Category 5E/6 or ISO/IEC Class D/E channel limits and using the3 rule for return loss Note: It is expected that further research on cabling components which are part of permanent link and channel adapters will result in improved accuracy "with adapter". Performance specification for the Fluke 5 acc_dsp-.doc 03/08/00 3:31 PM

6 5. Overview of computed measurement where the exceeds the minimum IIE and requirements based on TIA and EIA guidelines Return loss note: At low frequencies, the actual measurement accuracy is better as a result of the 3 rule. This is not included in the calculation of measurement accuracy. Practically, the return loss measurement accuracy is constant as a function of frequency. 1 MHz 10 MHz 100 MHz Parameter IIE IIE IIE Attenuation NEXT PS NEXT ELFEXT PS ELFEXT Return Loss * Table 5: IIE baseline minimum accuracy requirements vs accuracy. 1 MHz 10 MHz 100 MHz Parameter IIE IIE IIE Attenuation NEXT PS NEXT ELFEXT PS ELFEXT Return Loss * Table 6: IIE with adapter minimum accuracy requirements vs accuracy. Parameter Attenuation NEXT PS NEXT ELFEXT PS ELFEXT Return Loss * Table 7: baseline minimum accuracy requirements vs accuracy. Parameter Attenuation NEXT PS NEXT ELFEXT PS ELFEXT Return Loss * Table 8: with adapter minimum accuracy requirements vs accuracy. Performance specification for the Fluke 6 acc_dsp-.doc 03/08/00 3:31 PM