F i n i s a r |
1External Calibration
2Measurements are raw A/D values and must be converted to real units using calibration
3constants stored in EEPROM locations 56 – 95 at 2 wire serial bus address A2h (see
4 Table 3.15). Calibration is valid over specified device operating temperature and
5voltage. Alarm and warning threshold values should be interpreted in the same manner
6as real time 16 bit data.
71) Internally measured transceiver temperature. Module temperature, T, is given by the
8following equation: T(C) = Tslope * TAD (16 bit signed twos complement value) + Toffset.
9The result is in units of 1/256C, yielding a total range of
103.15 for locations of TSLOPE and TOFFSET. Temperature measurement is valid from –
1140°C to +125°C with an accuracy of ± 3°C. The temperature sensor is located in the
12center of the module and is typically 5 to 10 degrees hotter than the module case. See
13Tables 3.12 and 3.13 above for examples of temperature format.
142) Internally measured transceiver supply voltage. Module internal supply voltage, V, is
15given in microvolts by the following equation: V(µV) = VSLOPE * VAD (16 bit unsigned
16integer) + VOFFSET . The result is in units of 100µV, yielding a total range of 0 – 6.55V.
17See Table 3.15 for locations of VSLOPE and VOFFSET . Accuracy is ±100mV.
183) Measured transmitter laser bias current. Module laser bias current, I, is given by the
19following equation: I(µA) = ISLOPE * IAD (16 bit unsigned integer) + IOFFSET . This result is
20in units of 2 µA, yielding a total range of 0 to 131 mA. See Table 3.15 for locations of
21ISLOPE and IOFFSET. Accuracy is ± 10%. Early versions of the digital diagnostic standard
22
23readings.
24Count. All Finisar modules using a scale factor of 2µA/AD Count have an ASCII “A”
25written in byte 56 of the ‘vendor rev’ field (see table 3.1). Legacy Finisar modules using
26a scale factor of 1µA/AD Count contain either zero or ASCII space (20h) or one of two
27place holders:
284) Measured coupled TX output power. Module transmitter coupled output power,
29TX_PWR, is given in µW by the following equation: TX_PWR (µW) = TX_PWRSLOPE *
30TX_PWRAD (16 bit unsigned integer) + TX_PWROFFSET. This result is in units of 0.1µW
31yielding a total range of 0 – 6.5mW. See Table 3.15 for locations of TX_PWRSLOPE and
32 TX_PWROFFSET. Data is factory calibrated to absolute units using the most
33representative fiber output type. Accuracy is ±3dB. Data is not valid when the
34transmitter is disabled.
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