MAG/NAV/M1 - Data loss due to removal of contingent TSI instrument

TSI instrument was removed without mentor knowledge.  Associated TSI serial port was 
required for NAV data collection.  NAV data collection finally resumed after substituting null 
device for missing TSI serial port.

• heave_acceleration
• seanav_mode
• roll_angular_rate
• Sway directional velocity, toward port positive(sway_velocity)
• Heave: up positive(heave)
• yaw_angular_rate
• Surge: bow forward positive(surge)
• Heading: fron north(yaw)
• Sway: toward port positive(sway)
• pitch_angular_rate
• alt
• Pitch angle reported by tilt table(pitch)
• lon
• cycle_count
• seanav_monitor
• sway_acceleration
• surge_acceleration
• lat
• time
• Heave directional velocity, up positive(heave_velocity)
• Roll angle reported by tilt table(roll)
• base_time
• time_offset
• Surge directional velocity, bow forward positive(surge_velocity)