PDS_VERSION_ID         = PDS3                                                 
RECORD_TYPE            = STREAM                                               
OBJECT                 = TEXT                                                 
  PUBLICATION_DATE     = 2005-06-01                                           
  NOTE                 = "                                                    
      C40_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 Receiver (WBR), the Langmuir Probe (LP), the Sounder,      
      and the onboard Dust detection algorithm when using Trigger B4."        
END_OBJECT           = TEXT                                                   
END                                                                           
                                                                              
                                                                              
Trigger B4 Description                                                        
                                                                              
Sequence: C38, ...                                                            
                                                                              
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                  Time between Snapshots   
--------  ----------------  -----------------------  ----------------------   
MFR       25 - 12 KHz       EW, BZ                   32 seconds               
WFR       .1 - 2.5 KHz      EU(+5V),EV(+5V),LP(+4V)  10 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  1000   1              3.6-319 kHz          
H1   2E   y        y      2     n  20     1   60    25   325k-1.8MHz          
H2   1E   n        n      1     n  10     1   72    200  1.8M-16MHz           
                                                                              
Bands ABC require 3.16 sec to complete, H1 requires 1.57 sec, and H2 requires 
0.65 sec for a total of 5.62 sec per sweep. 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.