If your NFC device cannot contact the transponder it may be due to one of the following reasons:
The NFC device is not close enough to the transponder or is being held at an incorrect angle – reposition the NFC device next to the transponder. On the RT6 App tap: Advanced > NFC Optimise Tool to determine the best position for the NFC device.
The NFC device is not working correctly or has locked – Check/restart the NFC device.
The RT6 App has locked – redstart the RT6 App.
NFC interface has locked – power cycle the RT 6-1000 by removing the battery and waiting 60 seconds before replacing it.
Yes.
After commissioning and start-up of the system, the L/USBL transceiver, deployment machine, and gate valve will need a minimum of preventative and corrective maintenance to ensure the correct operation of the machine and consistent acoustic performance from the transceiver.
The procedures can be carried out without affecting the calibration offsets (CASIUS) of the L/USBL transceiver. We recommend that the maintenance which comprises visual inspections of bracing points and fixings, greasing routines, and also exercising of the moving parts (particularly the gate valve), is carried out on a monthly basis. Full details of these procedures can be obtained from our Customer Support team. From a purely operational point of view, failure to carry out the maintenance can lead to mechanical issues such as vibration of the pole which can have a significant impact on the performance of your system.
Carrying out the correct preventative maintenance routines not only prolongs the life of your deployment machine, but also greatly improves the performance of the acoustic system and reduce the risk of operational down time.
The deployment machine sealing section should be filled with Staburags NBU12K. On New machines the sealing section comes pre-filled.
To top up the grease remove one of the grease nipples and apply grease using a grease gun through the second grease nipple, until grease is seen coming out of the first grease nipple (this prevents over pressurisation). Once filled, fit the first grease nipple. Do not cross contaminate the sealing section with non-compatible grease.
Check grease compatibility before using an alternative.
A new feature in the latest release of Ranger 2/ Mini-Ranger 2 software allows an AUV fitted with an AvTrak 6 or AvTrak 6 Nano transceiver to receive USBL position updates on every navigation cycle.
This can be used to provide high update rate USBL aiding to a navigation system – something that’s particularly important during descent when the vehicle’s navigation system has no Doppler velocity bottom lock aiding, i.e. operating on free-inertial.
In addition to receiving high update USBL position observation, the feature allows the AUV to pass status information into the AvTrak 6’s data buffer, which is then retrieved automatically on the next navigation cycle and forwarded to the user’s topside mission control software.
It is also possible for the mission control software to substitute bespoke commands such as requesting the AUV status, emergency abort, navigation status and snippets of observed data for QC.
For details on how to update your software, email: [email protected]
The Hydraulic system uses light hydraulic oil ISO32 grade e.g. Mobil DTE24. The Hydraulic Power Unit tank holds 50 L of oil with 20 L being used in the hydraulic system.
Modem 6 uses advanced CRC (Cyclic Redundancy Checks) to ensure the integrity of any data received by the user. CRC is an error detecting code which is commonplace in digital networks; raw data files are assigned check values when transmitted which can be used at the receiving end to check for corrupt or missing data. CRC also attempts to correct corrupt data, without needing to re-request it.
Modem 6 supports two modes:
Acknowledged Mode
The Acknowledged mode uses full two-way communications to ensure that all data sent through the acoustic link is received by the user. Any data lost due to environmental challenges will be re-requested automatically. This mode is excellent for ensuring all data is received, however it can compromise the speed of the link in challenging conditions.
Fire and forget mode
The Fire and Forget mode continuously streams any new data to minimise latency, for applications where losing the occasional piece of data is not critical. Any data that is missing will not be re-requested. This is ideal for relaying near real time sensor data.
One of the many new features of Ranger 2 is Quick Track. This tool allows you to instantly start tracking a beacon with no other information required other than the unit’s address. You’ll no longer have to manually add the beacon to your job and go through the process of acoustically acquiring the beacon’s configuration. Ranger 2 takes care of everything, leaving you to get on with your subsea operations. Quick Track is particularly useful for checking system performance.
Modem 6 sends and receives data using MDFT (modem data frame transfer). MDFT is Sonardyne’s overall acoustic protocol for transferring data, used in Modem 6 products. Data is split into frames prior to transmission across the acoustic link, it is then reassembled at the other end before being outputted to the user.
What is the maximum MDFT frame size?
The maximum frame size (denoted here in terms of user payload) depends on the selected telemetry scheme.
• TS1 has a maximum frame size of 1,376 bytes
• TS2 has a maximum frame size of 2,656 bytes
• TS3 has a maximum frame size of 5,728 bytes
• TS4 has a maximum frame size of 27,488 bytes
• TS5 has a maximum frame size of 55,136 bytes
• TS6 has a maximum frame size of 30,048 bytes
• TS7 has a maximum frame size of 83,808 bytes
What if my payload is more than the maximum MDFT frame size?
In Fire and Forget mode the Modem 6 will continue to transfer the remaining data as long as the previous frame was successfully transferred. In Acknowledged mode the MDFT command reply will indicate that more data is available and another MDFT transfer can be scheduled to collect the remaining data.
The Modem 6 doesn’t use any initial handshaking or establishing sequence as the power levels, gain and telemetry scheme are configured ahead of time. There is a small header (10 bytes) appended to each packet that is used internally by the Modem to transfer acknowledgement and status information.