Show installed transceivers or cables

admin@sonic:~$ show interfaces transceiver presence
Port         Presence
-----------  -----------
Ethernet0    Present
Ethernet4    Not present
...
Ethernet80   Present
...

Show low-power mode

High-power is the default mode.

admin@sonic:~$ show interface transceiver lpmode
Port         Low-power Mode
-----------  ----------------
Ethernet0    Off
Ethernet4    Off
Ethernet8    Off
Ethernet12   Off
...

Enabling low-power mode:

admin@sonic:~$ sudo config interface transceiver lpmode Ethernet0 enable
 Enabling low-power mode for port Ethernet0... OK
 admin@sonic:~$ show interface transceiver lpmode
 Port         Low-power Mode
 -----------  ----------------
 Ethernet0    On
 Ethernet4    Off

Checking transceiver EEPROM data

admin@sonic:~$ show interfaces transceiver eeprom
Ethernet0: SFP EEPROM detected
        Application Advertisement: N/A
        Connector: No separable connector
        Encoding: Unspecified
        Extended Identifier: Power Class 1(1.5W max)
        Extended RateSelect Compliance: QSFP+ Rate Select Version 1
        Identifier: QSFP28 or later
        Length Cable Assembly(m): 1
        Nominal Bit Rate(100Mbs): 255
        Specification compliance:
                10/40G Ethernet Compliance Code: 40GBASE-CR4
                Fibre Channel Speed: 1200 Mbytes/Sec
                Fibre Channel link length/Transmitter Technology: Electrical inter-enclosure (EL)
                Fibre Channel transmission media: Twin Axial Pair (TW)
                Gigabit Ethernet Compliant codes: 1000BASE-CX
                SAS/SATA compliance codes: SAS 3.0G
        Vendor Date Code(YYYY-MM-DD Lot): 2016-06-20
        Vendor Name: Optech
        Vendor OUI: 00-00-00
        Vendor PN: OPQS28-T-01-PEU
        Vendor Rev: 00
        Vendor SN: OP1660BU0003

Ethernet4: SFP EEPROM Not detected

By specifying the -d or –dom flag, the user can get DDMI (Digital Diagnostics Monitoring) data.

admin@sonic:~$ show in transceiver eeprom Ethernet0 -d
 Ethernet0: SFP EEPROM detected
 Application Advertisement: N/A
 Connector: No separable connector
 Encoding: Unspecified
 Extended Identifier: Power Class 1(1.5W max)
 Extended RateSelect Compliance: QSFP+ Rate Select Version 1
 Identifier: QSFP28 or later
 Length Cable Assembly(m): 1
 Nominal Bit Rate(100Mbs): 255
 Specification compliance:
 10/40G Ethernet Compliance Code: 40GBASE-CR4
 Fibre Channel Speed: 1200 Mbytes/Sec
 Fibre Channel link length/Transmitter Technology: Electrical inter-enclosure (EL)
 Fibre Channel transmission media: Twin Axial Pair (TW)
 Gigabit Ethernet Compliant codes: 1000BASE-CX
 SAS/SATA compliance codes: SAS 3.0G
 Vendor Date Code(YYYY-MM-DD Lot): 2016-06-20
 Vendor Name: Optech
 Vendor OUI: 00-00-00
 Vendor PN: OPQS28-T-01-PEU
 Vendor Rev: 00
 Vendor SN: OP1660BU0003
 ChannelMonitorValues:
 RX1Power: -infdBm
 RX2Power: -infdBm
 RX3Power: -infdBm
 RX4Power: -infdBm
 TX1Bias: 0.0mA
 TX1Power: -infdBm
 TX2Bias: 0.0mA
 TX2Power: -infdBm
 TX3Bias: 0.0mA
 TX3Power: -infdBm
 TX4Bias: 0.0mA
 TX4Power: -infdBm
 ChannelThresholdValues:
 RxPowerHighAlarm  : -infdBm
 RxPowerHighWarning: -infdBm
 RxPowerLowAlarm   : -infdBm
 RxPowerLowWarning : -infdBm
 TxBiasHighAlarm   : 0.0000mA
 TxBiasHighWarning : 0.0000mA
 TxBiasLowAlarm    : 0.0000mA
 TxBiasLowWarning  : 0.0000mA
 ModuleMonitorValues:
 Temperature: 0.0C
 Vcc: 0.0Volts
 ModuleThresholdValues:
 TempHighAlarm  : 0.0000C
 TempHighWarning: 0.0000C
 TempLowAlarm   : 0.0000C
 TempLowWarning : 0.0000C
 VccHighAlarm   : 0.0000Volts
 VccHighWarning : 0.0000Volts
 VccLowAlarm    : 0.0000Volts
 VccLowWarning  : 0.0000Volts