Instrumentation interfacing and parameters monitoring for underwater neutrino telescopes.

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Instrumentation interfacing and parameters
monitoring for underwater neutrino telescopes.
SCI (Slow Control Interface)
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Requirement for an underwater neutrino telescope

• Monitoring of ambient parameters
• Water temperature
• Salinity
• Marine currents
• Optical properties of water (transparency)
• Periodical monitoring of system parameters
• Apparatus temperature
• Apparatus humidity
• Power dissipation of ambient instruments
• Pitch and orientation of optical modules
  mechanical framework
• Acoustic positioning system
• Instruments Control
• Power switch
• Galvanic isolation of external connections

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SCI features

• Modular system the SCI is composed by four
  physically distinguished modules
• Each module consists in a microcontroller and
  some signal conditioning electronics
• Each module manages a defined number of
  peripherals
• The same firmware can run on each microcontroller

• Peripherals highlights
• 2 Asynchronous serial ports RS232
• 1 Synchronous serial port SPI
• GPIO lines
• 5 ADC lines
• 8 Photomos switches
• 2 Current sensors

Intrumentationcurrent monitoring
Photomos switches
RS232
SPI
PIC 18LF6520
RS232

• SCI Electrical Characteristics
• 190 mA at 5.5 V unregulated

GPIO
ADC
4
SCI Board Top Layout Connection
RS232 Serial Com (galvanic isolation control)
Switched power
Instrumentation Power Supply 12V Unreg
Hardware ID selection
Microcontrollers PIC 18LF6520
Auxiliary Sensor 1 (Analog GPIO lines)
Acoustic Positioning System (RS232)
RS232 Serial Com (galvanic isolation control)
Switched power
Auxiliary Sensor 2
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Data transmission architecture
Floor Control Module Board
Optical modules
FCM Interface
FCM
Optical fiber
Hydrophones
Software
Slow Control Interface
Acoustic positioning system ACSA
Proprietary protocol on RS-232 Proprietary
protocol on RS-485 Proprietary protocol on
SPI Proprietary protocol on PCI bus STM-1 protocol
External Instruments
Internal Sensors
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Minitower arrangement in NEMO phase 1


Acoustic Doppler Current Profiler (ADCP)

Floor 4
Compass, tilt meter,temperature sensor, humidity
sensor in each floor (Inside the Floor Control
Module)
Floor 3

Transmissometer (C-Star),
Floor 2



Conducibility Temperature Deep (CTD)
Floor 1


2 hydrophones per floor 1 hydrophone (base
tower) 1Beacon (base tower)
Base Tower
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FCM board SCI communication protocol

• Hardware interface
• SPI 5Mbit/s
• SCI is slave, FCM is master. Each
  microcontroller is selected by FCM through its
  slave select line.
• Packet length 9 bytes per mController
• Each mController receives/sends a packet every
  STM-1 frame (125 us)

• Packet overview
• Different packets (asymmetric protocol)
• Optimized for offshore-gtonshore direction
• Its possible to know the SCI status every
  STM-1 frame (125 ms)
• Data are automatically transmitted from SCI. No
  demand is needed

• Header
• Its value is increased every transmitted
  packet.
• It allows to know the number of the currently
  converted analog channel whose value is in
  byte 6 and 7 (10 bit)
• It allows to identify and to comunicate a
  corrupted recived packet with byte 8 in the
  error detecting procedure.

• Serial Com
• Every serial data has its own place in the
  packet
• It is possible to transmit/receive at the same
  time through two serial ports
• SCI doesnt know instruments communication
  protocol
• Serial communication from onshore to offshore
  is point to point like

• Command data
• It allows to control external instruments
• (power switch, galvanic isolation) and
• to program SCI behavior (automatic or manual
  isolation, data rate of internal sensors)
• It allows to upload new firmware

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