Measurement Computing PCIM-DAS1602/16, Руководство пользователя

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CB.CFG. This file is accessed by the Universal Library for programmers. Note also that the Universal
Library is the I/O board interface for packaged applications such as SoftWIRE, and Agilent-VEE,
therefore the InstaCal settings must be made in order for these and other applications to run.
The base address and interrupt level are also stored in the system software. Once InstaCal installation
software is run, other programming methods such as direct IN and OUT statements can write and read
the PCIM-DAS1602/16 registers by reference to the base address and the offset from base address
corresponding to the chart of registers located elsewhere in this manual.
But a word of warning is in order here. Direct writes to the addresses simply by reference to the base
address of the PCIM-DAS1602/16 I/O registers is not advised. Since the addresses assigned by the PCI
plug & play software are not under your control, there is no way to guarantee that your program will run
in any other computer.
Not only that, but if you install another PCI board in a computer after the PCIM-DAS1602/16 addresses
have been assigned, those addresses may be moved by the plug & play software when the second board is
installed. It is best to use a library such as Universal Library or a program such as SoftWIRE,
DasWizard, or Agilent-VEE to make measurements with your PCIM-DAS1602/16.
2.2 1/10 MHz XTAL JUMPER
The 1/10 MHz XTAL jumper selects the frequency of the square
wave used as a clock by the A/D pacer circuitry (Figure 2-1). This
pacer circuitry controls the sample timing of the A/D. The
internal pacer output driving the A/D converter is also available at
the CTR 3 Output (pin 20) on the main connector. Select 10 MHz
unless you have reason to do otherwise.
Figure 2-1. 1 or 10 MHz Select Jumper
2.3 8/16 CHANNEL SELECT
The analog inputs of the PCIM-DAS1602/16 can be configured as
eight differential or 16 single-ended channels. Use the single-ended
input mode if you have more than eight analog inputs to sample.
Using the differential input mode allows up to 10 volts of common
mode (ground loop) rejection and will provide better noise
immunity.
The PCIM-DAS1602/16 comes from the factory configured for 16
single-ended inputs. The 8/16 switch is shown in the 8-channel
position in Figure 2-2. Set it for the type and number of inputs you
desire.
Figure 2-2. 8/16 Channel Select Switch
2
1
10
D efault 1M H z S how n
C L K S E L
8 /1 6 C H A N N E L S E L E C T S W IT C H
1 6 8
C H A N
(8 C h a n n e ls , D if fe re n tia l In p u t M o d e S h o w n )