SFP Plan
Main goals:
- Monitor health of transceiver
- Enable SFP exchange without the need for re-calibration
- Enhanced calibration for improved time accuracy
Means:
- Read out of additional Digital Diagnostic ADC values
- Storing of additional delays in the EEPROM of the SFP transceiver
Monitoring of health of transceiver
- Reading of voltage / current of transceiver
- Reading of temperature
- Reading of the RX power
- Reading of the TX power
Enhanced calibration for improved time accuracy
Additional EEPROM calibration parameter storage:
- Transceiver nominal RX and TX delays
- Optical power dependent RX delay curve
- Temperature dependent delay
- Also: Version, Date and UID
By storing part of the delay in the SFP EEPROM, these transceivers can
be delay-calibrated.
Since all information is 'self contained'. When inserting a calibrated
SFP transceiver, no
additional calibration will be required. Read more on the WR
Calibration wiki.
The transceiver nominal delays can be set to 0 in systems with a
traditional, relative,
calibration scheme, or the difference in delay with regard to the
standard transceiver can
be set.
RX power can be measured, and the optical power dependent delay can be
found using the power
dependent delay curve, and included in the round-trip delay calculation.
The globally Organizationally Unique Identifier (OUI) can be linked to
calibration entity and
additional information about the calibration, such as an official
certificate, measurement
procedures, metrological standards used and traceability information can
be received from this
entity and linked to the transceiver installed in the system.
Work in progress...
Calibration EEPROM format
Last updated: 15 Nov 2016