What is the transmit power for a 10GB SR?

lbee · ‎03-23-2009

Hi

Based on the data sheet of a 10GB SR port, there is a sentence that read: The launch power shall be the lesser of the class 1 safety limit or the maximum receive power. Class 1 laser requirements are defined by IEC 60825-1: 2001.

So the question is what is the requirement for the safety limit based on IEC 60825-1:2001? anoyone knows?

http://www.cisco.com/en/US/prod/collateral/modules/ps2797/ps5138/product_data_sheet09186a008007cd00_ps5455_Products_Data_Sheet.html

viyuan700 · ‎03-24-2009

As per the cisco link in ur message,

10GB SR port receive level are

Max-1dBm and Min -9.9dBm So the power should be between -1 to -9.9 dBm.

10GB transmit level are Max.-1.2 to Min.-7.3

so max -1.2 is less than -1.0 within range.

For more about class 1 power see the link below, i suppose the warning is because that Class 1 power level are not harmful to eyes. Sometimes power can be more and they are giving warning that even though it is Class 1 but be careful. OTher then class1 you will see a warning.

http://en.wikipedia.org/wiki/Laser_safety

lbee · ‎03-25-2009

hi

the specs of 10GB SR says:The launch power shall be the lesser of the class 1 safety limit or the maximum receive power. Class 1 laser requirements are defined by IEC 60825-1: 2001.

Yes the 10GB trasmit level is -1.2, but what is the class 1 safety limit? is it lower than -1.2? if it is lower than -1.2, then the 10GB trasnmit level will not be -1.2.

thanks

viyuan700 · ‎03-25-2009

I have no idea what that sentence exactly means.

I only found this link from ieee see page 6 for class 1 power levels at different wavelength. For 850nm i think it is near to -1 dBm.

http://www.ieee802.org/3/av/public/2006_11/3av_0611_kolesar_1.pdf

trasmit level is -1.2, but what is the class 1 safety limit? is it lower than -1.2? if it is lower than -1.2, then the 10GB trasnmit level will not be -1.2

I just see the trasmit power and what is the maximum receive level. I dont think you should worry about that sentence if tramit power is less than max receive level.

You can check if you have same type of card it is possible that you will get different tranmit power from each card though they are same .in this case it is going to be between -1.2 to -7.3