Measurement Computing 2000 Series Daqboar - Manual (Page 32)

1-6 Daq Systems and Device Overviews 10-18-02 DaqBoard/2000 Series & /2000c Series User’s Manual
Synchronous Output Operations
The DaqBoard/2000 Series and /2000c Series boards allow synchronous output of any D/A or P3 16-bit
Digital channels available at up to 100kHz for each channel. All D/A channels available and the 16-bit P3
Digital channel may have output streamed to them and clocked out synchronously. The D/A channels may
be configured for waveform output and the P3 digital channel may be configured for streamed digital
pattern output using the same clock sources.
Output Channel Configuration
Analog Output Channels
Each D/A channel can be configured for waveform output individually. If the D/A channel is not
configured for waveform output it then is available for asynchronous output operations.
Digital Pattern Output Channel
The 16-bit P3 Digital Port can be configured for streamed digital pattern output. If not configured for
streamed digital pattern output operations it then may be used for asynchronous digital I/O operations.
Synchronous Output Clocking
The DaqBoard/2000 Series and the /2000c Series boards allow clocking of the synchronized output by the
acquisition clock source, an internal, programmable pacer clock or by an external clock source. When the
clock source generates a new clock signal all outputs are updated concurrently. Regardless of the clock
source, the clock may not exceed the maximum update rate of 100kHz.
Synchronous Output Data Source
The DaqBoard/2000 Series and /2000c Series boards allow the data source for synchronized output
operations to be that of a memory based buffer or a file located on a mass storage medium. With either type
of output data source, the output data for all the channels are contained in the buffer and/or file. The file
path may be any file located on the on the machine or network accessible file.
Asynchronous I/O Operations
The DaqBoard/2000 Series and /2000c Series boards allow asynchronous input of any counter or digital
channel that is not currently configured for synchronous acquisition. The boards also allow for
asynchronous output to any D/A channels not currently configured for waveform output. Likewise, the
16-bit P3 digital port can be used for both asynchronous input and output operations if it is not currently
configured for streamed pattern output operations. In addition, the timer outputs can be programmed at any
time regardless of the current state of synchronous or asynchronous operations on other channels.
Digital I/O Channels
Local 8255 Channels
The DaqBoard/2000 Series and /2000c Series boards [which have digital I/O capabilities] have an
implemented Intel 8255 core in the digital I/O logic on the P2 port of the product. With the Intel 8255 there
are three 8-bit wide ports available for I/O and one 8-bit wide port for configuration purposes. The
configuration port is used to configure the other three 8-bit ports for either input or output operations.
Local 16-bit P3 Port
The 16-bit P3 Digital Port can be used as either an input, or an output port. With this port, no configuration
is required, the port simply outputs when written to and inputs when read.
Expansion Digital I/O
The DaqBoard/2000 Series and /2000c Series boards that have digital I/O capabilities have the ability to
expand these through the P2 port and the connection of applicable digital I/O expansion modules. These
modules are discussed in the DBK
Option Cards & Modules User’s Manual. When using the digital I/O
expansion modules the local P2 Intel 8255 digital I/O becomes inaccessible in lieu of the expansion
modules. These expansion modules provide additionally Intel 8255 ports as well as input isolation for
applications that require the expanded capabilities.