Earth Data EDR-217 Digitizer Description

The EDR-217 is the latest in the range of ruggedized digitizers and is nearly half the size of the EDR-209. Its robust, compact footprint, versatile connectivity options and ultra-low power consumption make ir ideal for use on remote projects where access is difficult. It provides up to eight independent channels of extremly high esolution with sample rates from 1 to 3,000 samples/sec. Channels can be switched off to reduce power so that any number from one to eight can be active. A selectable output word size of up to 32-bits is available.

SIGNAL TO NOISE

A signal to noise ratio of typically 145 dB is achieved at a sample rate of 100 Hz falling to 125 dB at 1,000 Hz using a 24-bit word. 150 dB is obtained below 10 Hz when a 32-bit word size is selected.

The signal bandwidth is always d.c. to 0.4 of the selected sample rate (± 0.1 dB) with over 140 dB of rejection above the half sampling frequency, negating any requirement for anti-alias filtering.

SIGNAL INPUTS

Up to eight channels of fully differential high resolutioninputs are available. Common mode rejection iw better than 100dB. One of four sensitivity settings can be selected. Up to ± 20 volts can be accommodated on the least sensitive setting. In additon to the standard for auxillary input low resolution channels that can be recorded at low sample rate for monitoring external parameters.

CONVERTERS

The converters use a 7th order Delta Sigma technique developed by Earth Data. In addition to their high dynamic range they are also free from spurious tones and artefacts present in alternative designs.

TIMING

The unit includes an internal GNSS reciever, capable of being configured to receive and track multiple GNSS constellations: GPS, GLONASS, Galileo, and BeiDou. In addition, the receiver can be configured to support various augmentation systems: SBAS (WAAS, EGNOS, MSAS and GAGAN), QZSS and IMES. Where condtions dictate, the unit away and power cycling modes can be used in both modes in order to conserve power. Alternative time sources such as NTP servers can be used.

STATUS

Power supply voltage, current, internal temperature, and GNSS status are continuously monitored and reported.

CONNECTION & INTERFACES

The EDR-217 can be configured and monitored via any standard HTTP web browser, in addition, it can also be configured as a SeedLink server enabling communication with external seismic systems. The internal mass storage media can be employed to store data in Mini-SEED format, or alternatively external mass storage units can be directly connected via USB. The unit supports the FTP and RSYNC protocols should remote users wish to download / synchronize any stored data files.

ENVIRONMENTAL

The EDR-217 is available in a fully sealed extruded aluminium case or as a board only OEM product. Standard operating temperature range is -20 °C to +60 °C, or an extended range of -40 °C to +60 °C.