Measurement Computing DaqBook 2000 Series - Manual (Page 68)

8-6 Taking Measurements 898695 DaqBook/2000 and DaqOEM/2000 Series
Digital I/O Channels
There are 24 Digital I/O channels available to DaqBook/2020; and 40 available to DaqBook/2001, /2005,
and DaqOEM/2001 and /2005. The channels are grouped as follows:
8 Channels, A0 through A7 from P2 [or JP2] Port A
8 Channels, B0 through B7 from P2 [or JP2] Port B
8 Channels, C0 through C7 from P2 [or JP2] Port C
16 Channels, Digital 0 through Digital 15 from P3 [or JP3]
These 16 channels do not apply to DaqBook/2020.
The DaqBooks allow for either synchronous scanning of digital input channels or asynchronous I/O
operations for all configured digital channels.
Counter Input Channels
Counter 0, 1, 2, 3 (CTR0, CTR1, CTR2, CTR3)
The DaqBooks allow synchronous scanning of four16-bit counter input channels. The 4 channels can be
cascaded into two 32-bit counter channels. For either cascaded or non-cascaded counter channels each
channel can be configured for:
• Pulse Counting Mode – specifies that each counter should be cleared upon being
read and placed into the input scan.
• Totalize Counting Mode – specifies that each counter is to free-run and not be
cleared during the input acquisition.
Synchronous Input Acquisition Clocking
A /I Clock
The DaqBooks allow clocking of the synchronized inputs either by an internal, programmable pacer clock
or by external clocking. These products use a sequencer to implement a multiplexing approach to
gathering the input data. This means that with either internal or external clocking the entire channel scan
(including the sampling time for each channel) may not exceed the maximum aggregate rate of 200 kHz.
Synchronous Output Operations for DaqBook/2020, DaqBook/2001, and DaqOEM/2001
DaqBook/2020, DaqBook/2001, and DaqOEM/2001 allow synchronous output of any D/A channels
available at up to 100 kHz for each channel. All D/A channels may have output clocked out
synchronously.
Output Channel Configuration
Analog Output Channels
DAC0, DAC1, DAC2, DAC3
(AO0, AO1, AO2, AO3)
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.
Synchronous Output Clocking
A / O Clock
DaqBook/2020, DaqBook/2001, and DaqOEM/2001 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 100 kHz.
Synchronous Output Data Source
DaqBook/2020, DaqBook/2001, and DaqOEM/2001 allow the data source for synchronized DAC output
operations to be that of an internal memory-based buffer. The output data, for all channels, is contained in
the buffer.