The Instrumentation Unit (IU) of the Calibration Unit (CU) Status 6/12/2016 Pascale Keller for the CPPM group APC meeting, 7/12/2016

The Instrumentation Unit (IU) for the CU Reminders : Inductive Instrumentation Unit directly inspired of the Albatross line (but Albatross is not linked with a cable to an infrastructure, data transfert via acoustic modem) The IU is composed by one inductive Instrumentation Line (IL) and one titanium Instrumentation Base container (IB) + one dead weight The instruments are autonomous in terms of energy using internal batteries The IU is recoverable in order to change the batteries and to calibrate some of the instruments that need recalibration periodically (about once every 2 years) The IU will be connected to the electric interlink cable with a ROV via the IB wet matable connector

The Instrumentation Unit (IU) for the CU Schematic diagram :

IU : status on inductive modem system (Seabird) Test bench operationnal in CPPM : IMM (inductive modem) linked to a PC via RS232 (simulates the CB of CU) IMM connected on a 50 cm wire (simulates the interlink cable to CB) via an inductive core (simulates the Inductive Cable Coupler) Simul. Inductive cable Simul. Inductive cable coupler Simul. IU Manager (CB) IMM : inductive modem UIMM serial/inductive adapter : to interface Aquadopp currentmeter

status on instruments & inductive devices Inductive devices status : IMM (Inductive Modem) : in CPPM ICC (Inductive Cable Coupler) : to be ordered UIMM (serial/inductive adapter) to interface Aquadopp : one in CPPM SBE44 (serial/inductive adapter+battery) to interface miniSVS : to be ordered 300m MSI inductive cable : in CPPM Instruments status : CTD Seabird : one inductive native in CPPM, 2 non inductive native in CPPM Currentmeter Aquadopp : 3 non inductive native in CPPM (need to be interfaced via UIMM) Velocimeter Valeport : 1 ordered by CPPM, to be received (need to be interfaced via SBE44)

status on IU/CB communication The IMM communicates via RS232 and it is preferred to be adapted into another communication standard in order to trnasmit data over electric cable from 50 to 100 m (or more) length The possible choices were : ethernet, RS485 and RS422 We performed tests with RS485 and RS422 : RS485 is quite touchy to adjust with ending resistors and needs to manage the RTS/CTS logic signals RS422 tests were successful and it is more simple to be operated but need 4 wires because it is a full duplex communication RS422 Test setup : status on IU/CB communication

status on IU/CB communication RS422 Test setup : Conversion RS232/422 board : 50m electric test cable status on IU/CB communication We performed tests using a 50m submarine electric cable (lent by INSU) similar to the on that is foreseen for the french site The tests have been performed from 9600 bauds to 115200 bauds with success Data transfert directly between 2 PC via 50m cable Communication between IMM and PC via 50m cable

status on IU/CB communication Conversion RS232/422 Electronics schematics proposal : Estimated power need : 4w @12V  The IU will be linked to the Calibration Base of the CU via one 50 m electric serial cable using RS422 serial communication for the data transfert : 4 electrical points for the RS422 link 2 electrical points for the 12V power (supplied by CB) Consultation of the submarine cable have been launched (Macartney/ODI)  Waiting for proposals

status on mechanics Global mechanics specifications : Essential elements of subsystem line : buoy , instruments (devices), anchor (design in progress). Deployment and recovery each 2 years with optimal safety Anchor functions : Deadweight (in steel materials) for anchorage (it is possible to add additionnal mass) The titanium frame integrate : the release system the connexion/deconnexion tools for the junction to the CB at the IU a survey and cleaning port a titanium container ‘IB’ A sling with four legs to connect to the instrumented cable Compacity of anchor (link between the deadweight and titanium frame) during recovery and deployment phasis.

status on mechanics

status on mechanics  Mechanics design currently under going

status on mechanics / operations => Procedures and tools under study : Tools :   The DU deployment mechanical tools could not be used, need specific tools for the deployment and recovery of the IU The basic idea is that the IU will be deposed to the seabed from the surface boat using the winch with absolute positioning Because of their fragility, the instruments will be attached on the mooring line one by one on the boat while the line will descend (idem for the IU recovery)  Procedures : Boat procedures to be defined (should use the Albatross experience). After deployment, the IL will be connected to the electric interlink cable with a ROV via the wet matable connector. For the recovery, a ROV will deconnect the interlink cable and the acoustic released that will be activated in order the IU to go up thanks to adapted syntactic foams buoys.