TDT RZ2, Manual, Page: 62 / 736

1-56 System 3
RZ5 BioAmp Processor
Fiber Oversampling (acquisition only)
The fiber optic cable that carries the signals to the fiber optic input ports on the
RZ5 has a transfer rate limitation of 6.25 Mbits/s. With 16 channels of data and 16
bits per sample, this limitation translates to a maximum sampling rate of ~25 kHz.
However, the need may arise to run a circuit at a higher sampling rate while still
acquiring data via a fiber optic port. The two fiber optic ports on the RZ5 can
oversample the digitized signals that have already been sampled up to 2X or ~50
kHz. This will allow the RZ5 to run a DSP chain at ~50 kHz and still sample data
acquired through an optically connected preamplifier that digitized the incoming data
stream at its maximum rate of ~25 kHz.
Oversampling is performed on the base station. The signals being acquired will still
be sampled at ~25 kHz on the preamplifier. This means that, even with
oversampling, signals acquired by an optically connected preamplifier are still governed
by the bandwidth and frequency response of the preamplifier.
Fiber Optic Output (Stimulator) Port
The output port, labeled Stimulator, can be used to transfer microstimulation
waveforms to the Stimulus Isolator and/or to control its digital output.
Important! This fiber optic port is disabled if the sampling rate of the system is set to a value
greater than ~25 kHz.
Monitor Speaker
The RZ5 is equipped with an onboard speaker. To use the speaker feed the desired
signal to output channel 9 using a DacOut component. The speaker is provided
primarily for audio monitoring of a single channel of electrophysiological potentials
during recording.
Digital I/O
24 bits of programmable digital I/O is divided into three bytes (A, B, and C) as
described in the chart below. All digital I/O lines are accessed via the 25-pin
connector on the front of the RZ5 and bits 0 - 3 of byte C are available through
BNC connectors on the front panel labeled Digital. See “RZ5 Technical
Specifications” on page 1-59, for the DB25 pinout and BNC channel mapping.
See the “Digital I/O Circuit Design” section of the
RPvdsEx Manual
for more
information on programming the digital I/O.
Digital I/O Description DB25 BNCs Notes
Byte A bits 0 - 7 Yes No byte addressable
Byte B bits 0 - 7 Yes No byte addressable
Byte C bits 0 - 7 Yes Yes* bit addressable
*Note: Byte C Bits 0 - 3 are available via front panel BNCs
The data direction for the Digital I/O is configured using the RZ5_Control macro in
RPvdsEx.