Data Acquisition
Continuous: Regular output from all sensors at 1, 2, 4 or 8Hz.
Burst: Regular sampling pattern, where instrument takes a
number of readings, then sleeps for a defined time.
Trip/Profile: Data is output as a chosen parameter changes by a set
value, usually Pressure for profiling.
Conditional: Instrument sleeps until a selected parameter reaches a
set value.
Delay: Instrument sleeps until predefined start time
Communications
The instrument will operate autonomously, with setup and data extraction
performed by direct communications with PC before and after deployment.
It also operates in real time, with a choice of communication protocols for a
variety of cable lengths, all fitted as standard and selected by pin choice on
the output connector:
Standard
RS232 Up to 200m cable, direct to serial port via USB adaptor
RS485 Up to 1000m cable, addressable half duplex comms
Options
FSK 2 wire power & comms up to 6000m cable (cable
dependant)
Baud Rate: 2400 - 115200 (FSK fixed at 19200, USB 460800)
Protocol: 8 data bits, 1 stop bit, No parity, No flow control
Memory
The MIDAS ECM is fitted with 16Mb solid state non-volatile FLASH memory.
Total capacity depends on sampling mode; continuous & burst modes have
a single time stamp at the start of the file, trip mode (profiling) stores a time
stamp with each reading. A single line of current data uses 10bytes, with
each additional parameter taking 2bytes and a time stamp uses 7 bytes.
The examples are for an instrument measuring speed, direction and CTD.
Continuous: >520,000 data points
Profile: >360,000 data points (>15 profiles to 5000m).
Electrical
Internal: 8 x D cells, 1.5v alkaline or 3.6v lithium
External: 9 - 30vDC
Power: 1.7W (sampling), <1mW (sleeping)
Battery Life: >100 hours operation (alkaline)
>250 hours operation (lithium)
Connector: Subconn MCBH10F
Physical
Materials: Titanium housing, polyurethane sensor
components, stainless steel (316) cage
Depth Rating: 5000m (titanium), 500m (acetal)
Instrument Size: 88mmØ x 665mm long
Cage Size: 750 x 140 x 120mm
Weight (in cage): 20kg (titanium), 12kg (acetal)
Phipping: 130 x 37 x 32cm, 38kg (titanium), 34Kg (acetal)
Software
System is supplied with DataLog Express Windows based PC software,
for instrument setup, data extraction and display. DataLog Express is
licence free.
