We should expect Rx light no lower than –13.50 [Expected range between –9.0 to –13.50] 

 

show controllers [interface] phy | i "Rx|Tx" – to display light levels on IOS XR 

 

show interface [port number] trans det | i Power 

 

show int [port#] tra det | i Tx|Rx 

 

show hw-module subslot 0/2 transceiver 1 status 

 

To check SFP Tx 

show int [interface] transceiver 

show int [interface] transceiver detail