TDT RZ2, Manual

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System 3 4-11
RA16BA Medusa Base Station
Sampling Rate Considerations
There are no onboard analog-to-digital converters (As) on the Medusa base
station. When acquiring data, a preamplifier does this conversion. Since the fiber
optic connection from a preamplifier to the base station has a transfer rate limitation
of ~25 kHz, circuits utilizing this data acquisition must use a sample rate of ~25
kHz or less. Otherwise (i.e. circuits with digital-to-analog conversion only), the
maximum sample rate is ~50 kHz.
Force
Pushing a paper clip in to the pinhole next to the clip light deletes the microcode on
the base station. Once the microcode is deleted the RA16 base station will need to
be reprogrammed.
USB Transfer Rates
USB transfers are limited to 100,000 samples per second of 32-bit data. 16-
channels of ~25 KHz data produce 400,000 samples of data per second. Data
reduction techniques such as Compress to 16 and Shuffle to 16 will reduce the data
size without significant loss of information. Selective channel analysis and filtering can
further reduce the amount of data transferred.
Memory
The RA16BA Medusa comes standard with 32MB of RAM. At 16-channels in 16-bit
mode, 32MB would give around 40 seconds of continuous data acquisition. Each
additional base station could add an additional 2.5 minutes of continuous data
acquisition.
RA16 Technical Specifications
Note: The RA16BA has no onboard AD converters. Technical specifications for the AD
converters are found under the preamplifier's technical specifications.
DSP
50 MHz Sharc 21065, 150 MFLOPS
Memory
16 MB SDRAM or 32 MB SDRAM
D/A
8 channels, 18-bit sigma-delta
Sample Rate
48.828 kHz maximum
Frequency Response
3 dB at 3 Hz - Nyquist (~1/2 sample rate)
Voltage Out
+/- 10.0 V (AC coupled)
S/N (typical)
90 dB (20 Hz to 25 KHz)
Distortion (typical)
-70 dB for 1 KHz output at 0.7 Vrms
Sample Delay
18 samples