GarrettCom 1016, 1024, 1008 Magnum 1000 Workgroup Hubs, Installation and User Guide 04/02, Media

Magnum 1000 Workgroup Hubs Installation and User Guide (04/02)

3.3.8Power Budget Calculations for Magnum 1000 Series RPM’s with Fiber

Media

Receiver Sensitivity and Transmitter Power are the parameters necessary to compute the power budget. To calculate the power budget of different fiber media installations using Magnum products, the following equations should be used:

OPB (Optical Power Budget) = PT(min) - PR(min)

where PT = Transmitter Output Power, and PR = Receiver Sensitivity

Worst case OPB = OPB - 1dB(for LED aging) - 1dB(for insertion loss) Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/Km]

where the “Cable Loss” for 62.5/125 and 50/125∝m (M.m) is 2.8 dB/km, and the “Cable Loss” for 100/140 (Multi-mode) is 3.3 dB/km,

and the “Cable Loss” for 9/125 (Single-mode) is 0.5 dB/km

The following data has been collected from component manufacturer’s (HP’s and Siemens’) web sites and catalogs to provide guidance to network designers and installers.

Fiber	Speed,		Std.		Cable	X’mitr	R’cvr	Worst	Worst*	typical	typical*
Port	Std.	Mode	km	Wave	Size	Output	Sens.		distance	OPB,	distance
Module			fdx	-	∝m		PR ,dB	OPB,	Km, fdx	dB	Km, fdx
			(hdx)	length		PT , dB		dB
				nm
RPM-MST,	10 Mb	Multi-	2		62.5/125	-15.0	-31	14	5	17	6
				850	100/140	-9.5	-31	19.5	5.9	23.5	7
MSC	FL	mode	(2)
					50/125	-19.5	-31	9.5	3.4	13.5	4.8
RPM-	10 Mb	Single-	10	1300	9/125	-30	-39	7	14	13	26
SMF (ST)	FL	mode	(5)

*Note: The use of either multi-mode or single-mode fiber to operate at 100Mbps speed over long distances (i.e., in excess of approx. 400 meters) can be achieved only if the following factors are both applied:

•The 100Mb fiber segment must operate in full-duplex (FDX) mode, i.e. the full-duplex (factory default) setting for 100Mbps fiber ports must be used, and

•The worst-case OPB of the fiber link must be greater than the fiber cable’s

passive Attenuation.

(Attenuation = Cable loss + LED aging loss + Insertion loss + safety factor)

3.3.9Rack-mounting

Installation of a Magnum 1000 Series Hub in a 19” rack is a simple procedure. The units are 1U

Magnum 3000

Stackable Hub

GARRETT

(1.75”) high. When properly installed, the front-mounted LED status indicators should

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