Siemens DataNET Hub (DNH) user manual Step Action

Models: DataNET Hub (DNH)

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Signal Equalizer Settings for Non Recommended Cable or Unknown Cable Lengths, Continued

Step

Action

3.Examine the recorded signal levels and determine the dB loss for each port; refer to Table 2-2.

Example:

With these signal levels, port 4 is the lowest level, so no at- tenuation is required. Its signal level becomes the reference for comparing the remaining ports’ signal levels.

The next strongest signal is on port 1. 1.6/1.25 = 1.28

20 log 1.28 = 2.1 dB or

ratio of 1.28

This is within the 3-dB variance allowed, Use Selection 1 or 0 dB (ratio 1) setting.

The next strongest signal is on port 2. 1.75/1.25 = 1.4

20 log 1.4 = 2.9 dB or

ratio of 1.4

Since 2.9 dB meets the 3 dB variance allowed, selection 2 can be used (3.5 dB loss), which will put the level at about 0.6 dB below the signal on port 4.

Next is the signal on port 8. 4.5/1.25 = 3.6

20 log of 3.6 = 11.1 dB or

ratio of 3.6

Since this signal is 11.1 dB stronger than the signal on port 4, the attenuator board on port 8 needs to be set to selection 5 (11 dB loss). This should put its signal at about 0.1 dB above the signal of port 4.

40 Installation

2000585-001

Page 48
Image 48
Siemens DataNET Hub (DNH) user manual Step Action