PDS_VERSION_ID         = PDS3                                                 
RECORD_TYPE            = STREAM                                               
OBJECT                 = TEXT                                                 
  PUBLICATION_DATE     = 2007-09-23                                           
  NOTE                 = "                                                    
      TRIG_B4.TXT describes the RPWS instrument configuration for the         
      High Frequency Receiver (HFR), the Medium Frequency Receiver            
      (MFR), the Low Frequency Receiver (LFR), the Waveform Receiver          
      (WFR), the Wideband Reciever (WBR), the Langmiur Probe (LP), the        
      Sounder, and the Dust detector algorithm when using Trigger B4."        
END_OBJECT           = TEXT                                                   
END                                                                           

Trigger B4 Description                                                        
                                                                              
Sequence:  S05, ...                                                           
Trigger B4 ( Titan deltaN/N mode)                                             
                                                                              
This mode assumes a background survey mode, such as 8A or A0, is running.     
The duty cycle of the Langmuir Probe and the WFR are increased.  The WFR is   
connected in 3-channel mode to the two voltage-biased cycliners, EU and EV,   
and their voltage is set to +5V.  The third WFR channel is connected to the   
LP sphere, which is biased at +4V.  Every 10 seconds a 1024-sample (per       
channel) data set is acquired by the WFR in 2.5KHz mode.  The Langmuir Probe  
performs a sweep every 20 seconds and between sweeps, does a 256-sample       
density mode measurement at 20 Hz.  The MFR is connected to the EW antenna,   
since the EX antenna is being used in deltaN/N mode.                          
                                                                              
Also the LFDR and MFDR use the EW antenna for their electric field            
measurements (in addition to the BX antenna).  They each acquire data once a  
minute.  The WBR acquires data in 80-KHz mode.  Sounder is disabled, and      
dust detection is disabled in this mode.                                      
                                                                              
The target bit rate is 100 kbps.  Measured bitrate was about 55 kbps when in  
S&ER-3 mode, measured during C39.  In C40, at a higher rate telemetry mode,   
the measured bitrate was 99 kbps.                                             
                                                                              
Receiver  Frequency Range   Sensors                  Snapshot Spacing         
--------  ----------------  -----------------------  ----------------         
LFR       1 - 25Hz          EW, BX                   60 seconds               
MFDR      70Hz - 1.7KHz     EW, BX                   60 seconds               
MFR       25 - 12 KHz       EW, BZ                   32 seconds               
WFR       .1 - 2.5 KHz      EU(+5V),EV(+5V),LP(+4V)  24 seconds               
HFR       3.6 KHz - 16 MHz  EX, EW                   10 seconds               
LP        N/A               Langmuir Probe           20 seconds               
WBR       0 - 80 KHz        EX                       0.125 second             
                                                                              
                                                                              
                                                                              
The HFR is in a modified "Composite Survey" mode, which includes both auto-   
and cross-correlations for H1, and should be set up to use the faster         
integration constants of the "Night-time" survey mode, running either         
trigger 8E or A0 or A8 prior to this trigger.  This mode is defined by:       
                                                                              
                                                                              
          Correlations Channels    Integ.           Size Frequency            
Band Ant. Auto- Cross- per Band df Period Rep Steps kHz  Start - Stop         
---- ---- ----- ------ -------- -- ------ --- ----- ---- ------------         
ABC   2E    y     y       16    n    500  1              3.6-319KHz           
HF1   2E    y     y        2    n     20  1     60    25 0.325-1.825MHz       
HF2   1E    n     n        1    n     10  1     72   200 1.825-16.225MHz      
                                                                              
Bands ABC require 1.580 sec to complete, H1 requires 1.573 sec, and           
H2 requires 0.886 sec for a total of 4.039 sec per sweep.  The hfr            
cycle time is 10.000 seconds.                                                 
                                                                              
                                                                              
However, the time between analyses is set to 10 seconds to avoid              
interference from the LP sweep.                                               
                                                                              
No Sounder measurements are made in this mode.  No onboard dust detection is  
done either.