Chapter 3
Hardware Overview
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National Instruments Corporation
3-3
Getting Started with Your PCI/PXI-6810 SDA
Serial Data Processor
The serial data processor is a reconfigurable FPGA that contains most
of the 6810 hardware features. The processor is initially empty after
system power-on. When you run the SDA soft front panel or use another
SDA-based application, the 6810 instrument driver downloads the
appropriate firmware into the serial processor. The processor supports
two channels where a channel can be either input or output. A channel
converts data between serial and parallel formats and incorporates
trigger logic to control the serial channel.
RS-232 Transceivers
Each channel has dedicated RS-232 transceivers. The Read Data (RD)
signal is sensed when the associated channel is configured for input.
The Transmit Data (TD) signal is driven when you configure the
associated channel for output.
RS-485 Transceivers
Each channel has a dedicated RS-485 transceiver. Each transceiver
either transmits or receives data depending on the configuration of the
associated serial channel.
Adjustable Voltage Transceivers
These are also called general-purpose transceivers. These tranceivers
can either transmit or receive data, modulated at any voltage
within ±10 V to a resolution of 40 mV. Two transceivers are dedicated
to the serial channels. A third transceiver is dedicated to an external
clock. Depending on how you set up the clock source in the soft front
panel, the clock transceiver either transmits the internal clock for use in
external hardware, or receives a clock input from an external source.
Static Digital I/O
The 6810 device has eight digital I/O signals for static input and output.
You can use the signals to control external hardware or set up a device
under test. The tranceivers operate at either 5 V or low-voltage signal
levels.
