User manual: Installation and Operation of Direction Finder System RHOTHETA RT-600 / SAR-DF 517
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Detailed Description of important values for practical use:
•
Status: byte [2]
Receiving Bit 0 of this value (LSB) indicates signal receiving.
Bit 0 = 0, then no signal is received and so on no bearing is available.
Bit 0 = 1, then beraing is possible.
Bit 1: if(1) then Squelch is controlled by AU (active at modes: CospasSarsat Decode, CospasSarsat
Scanning, LoJack with Filter=ID only)
•
Error: bytes[4..5]
16 bit value
each set bit corresponds to the error no. (Refer to the chapter Error messages)
Example:
- 0x0000
No error
- 0x0800
Bit No. 11 Set ( = No AU Error)
•
Actual DCU Page: byte[6]
indicates actual operating mode of DCU
0 = Standard bearing page
1 = Frequency memory page
2 = CospasSarsat decoding page
3 = LoJack decoding page (ID edit)
•
Frequency: bytes [8..11]
32 bit value
actual adjusted frequency [Hz]
Example:
- 0x073DF160
1215000000
121.5 MHz
•
Active Band:
Standard Version [A]:
0=VHF Airband; 1=VHF marineband sea; 2=VHF marineband coast; 3=UHV airband; 4=CospasSarsat;
LE Version [L]:
0=VHF Airband; 1=LoJack; 2=Lifesaver; 3=ETS; 4=CospasSarsat;
•
Actual Squelchlevel: byte [13] Range: [0..60]%
without signal, the actual squelchlevel should always be adjusted a little bit over the noise level
(Refer to the chapter Squelch operation)
•
Level: byte [27] Range: [0..99]%
actual receiving level (without signal this value is equal to the noise level).
If a signal is received, then this value corresponds to the signal strength of this signal.
•
Relative Bearing averaged: byte [28..29]
16 bit value Range [0…359, 0xFFFF]
if the value = 0xFFFF, then no valid bearing is available, otherwise this value contains the actual
averaged bearing information in Deg. [0°..359°].
Example:
- 0X0114
276° bearing (= left side oriented to heading)
•
Bearing Live Min/Max: byte[30..31] & [32..33] -
16 bit values Range [0…359, 0xFFFF]
Only for signal quality or additional information – NOT recommended for bearing indication
The relative live bearing field contains the max/min bearing in degrees without averaging. The relative
live bearing reacts faster than the normal relative bearing, but it has not the precision of the averaged
bearing.
The Min/Max Bearing Values are calculated within a time period of approx. 250ms. If they are very close
together (for example “124” and “128” degrees), then the signal quality is quite good. A wide span of the
min/max values (for example “97” and “162”) shows very noisy, but nevertheless bearable signal quality.
