Campbell Scientific CSAT3 CSAT3 3-D Sonic Anemometer - Page 30
Diagnostic Word
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CSAT3 Three Dimensional Sonic Anemometer Ux Input Location: The Input Location to store the first of five data values to an EDLOG datalogger. The CSAT3 returns the following data after receiving the "Trigger and Get Data" or "Get Data after a Group Trigger" command in the option parameter: ux, uy, uz, c or Ts, and a diagnostic word, where ux, uy, and uz are the wind speeds along the x, y, and z axes defined by the anemometer head (see FIGURE 4-1), c is the speed of sound, and Ts is the sonic virtual temperature. The wind speed and the speed of sound are in units of m s-1, and Ts is in degrees Celsius. If the Reps option in parameter 1 is greater than 1, the number of sequential Input Locations used is Reps ∗ 5. 10.4 Diagnostic Word The fifth output from the CSAT3 is the diagnostic word. The diagnostic word describes the status of the anemometer and is useful in filtering data. For example, when the anemometer is locking in on the ultrasonic signals after receiving the acquire signals command, the NaN or -99999's it sends to the datalogger for the science data can be filtered out of the statistics based on the diagnostic word, see the example program in Section 10.6 and 10.7. The CSAT3 ()/SDM-CSAT3 instruction (P107), decodes the diagnostic word and represents it in base 10. The bits in the diagnostic word are grouped together into three categories. Bits 15 through 12 are four diagnostic flags (see TABLE 10-5 and TABLE 10-6), bits 11 through 6 represent the range the measurements are reported in (used by the datalogger), and bits 5 through 0 are a counter. A detailed description of decoding the diagnostic word is given in Appendix B. TABLE 10-5. Diagnostic Word b15 - b12 diagnostic flags Diagnostic Word b11 b10 b09 b08 ux range uy range b07 b06 uz range b05 - b00 counter The following are four specific Diagnostic Words (Base 10) and the situation that produces them: NaN or -99999, Anemometer does not Respond. This is the special case when the datalogger attempts to address an anemometer and the anemometer does not answer. This occurs if the anemometer is not connected to the SDM bus, the anemometer is not connected to a 12 Vdc power supply, or none of the anemometers on the SDM bus are set to the SDM address in the CSAT3 ()/SDM-CSAT3 (P107) instruction. 61440, Lost Trigger. The anemometer has lost the trigger source, in this case all the diagnostic bits are set high, the range bits are set low, and the counter bits are low. This occurs if the anemometer is disconnected from the SDM bus; e.g. a loose SDM clock line. To bring the anemometer back on-line, connect the CSAT3 to the SDM bus and execute the CSAT3 ()/SDM-CSAT3 (P107) instruction with the "Set Execution Parameter" Command/Option. 61503, No Data Available. The anemometer has no new data. In this case all the diagnostic bits are set high, the range bits are low, and all the counter bits are high. This occurs immediately after the anemometer receives the acquire signal command from the datalogger, e.g. a CSAT3 ()/SDM-CSAT3 (P107) instruction with the "Set Execution Parameter" Command/Option. The no new 22