OCEANO RT2500S/RT5000S Series – User Guide
II.8
Optional Pressure Telemetry Mode
The pressure sensor and the associated telemetry are optional. The pressure sensor
belongs to the Keller PA23 700 Bar series with the following characteristics:
•
Output signal: 4 - 20 mA
•
Data range : 0 - 700 Bar
•
Range of linearity validity: -10 - 80 °C
This function is activated upon Transponder or Responder positioning interrogation. The
pressure telemetry cycle is added or not after the positioning transmission depending on
the status of the Telemetry mode (this mode is activated by the Telemetry ON and
terminated by the Telemetry OFF commands from the acoustic remote control). Pressure
data can also be forwarded through RS232 serial link if the responder option is available.
Figure 8 – Pressure telemetry
Pressure Calculation:
Case of a LBL configuration (if CRF is Tonal)
The 12 bits of the measurement are totally transmitted by pulse to pulse time modulation.
T1: time coding of the value of the 12 bits of the measurement
T0: minimum separation between pulses so 2 s
K0: time resolution of the coding so 2.442 ms
The value of the measurement M is given by: M = (T – T0) / K0
The coding unit of pressure measurement is 2 dbar:
Pressure = 2 x M (in dbar)
Case of a USBL configuration (if CRF is MFSK-POSI)
The 12 bits of the measurement are partially transmitted by pulse to pulse time modulation
state and partially by MFSK Costas code state.
T1: time coding of the value of the 8 most significant bits of the measurement
T0: minimum separation between acoustic pulses so 350 ms
K0: time resolution of the coding so 2.5 ms
M1 = (T-T0) / K0
CAF2 / CRF2: MFSK pulse for the 4 least significant bits of the measurement
M2: number of permutation CAF2 and CRF2 (0 à 15)
MU–RT8x1–AN–001 Ed. M – September 2013
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Summary of Contents for OCEANO RT2500S Series
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