Programming
Chapter 5
SCXI-1100 User Manual
5-8
© National Instruments Corporation
3. Write FF09 to the Am9513 Command Register to select Counter 1 Load Register.
4. Write the number of samples to be taken per scan list entry (2 to 65,535) to the Am9513
Data Register to load Counter 1.
5. Write FF41 to the Am9513 Command Register to load Counter 1.
6. Write FFF1 to the Am9513 Command Register to step Counter 1.
7. Write FF21 to the Am9513 Command Register to arm Counter 1.
8. Set the SCANDIV bit in Command Register 1.
2. Module Programming
This section describes the programming steps for various scanning possibilities.
Single-Module Multiplexed Scanning (Direct)
To perform simple channel scanning, cable the SCXI-1100 to a data acquisition board. See
Chapter 2, Configuration and Installation, for more information.
To program the module for scanned-channel measurements, write the binary pattern
XXXGGGGG
10XCCCCC 00000101
to the SCXI-1100 Configuration Register.
CCCCC
represents the
starting channel number.
Single-Module Multiplexed Scanning (Indirect)
Channel Scanning from Other Modules. To scan measurements from other modules, cable the
SCXI-1100 to a data acquisition board. See Chapter 2, Configuration and Installation, for more
information. The module programming steps are as follows:
1. Perform any necessary programming to ensure that no modules are driving Analog Bus 0.
For an SCXI-1100, clearing AB0EN in the Configuration Register ensures that the
SCXI-1100 output is not driving AB0.
2. Write the binary pattern
XXX00000 10XXXXXX 00101011
to the SCXI-1100
Configuration Register. This step disables the SCXI-1100 from driving Analog Bus 0 and
allows Analog Bus 0 to drive MCH0 through the output buffer.
3. Program the other module to be scanned.
Channel Scanning from the SCXI-1100 via Another Module. To scan the SCXI-1100 via other
modules, cable the other module to a data acquisition board; the other module must be able to
transfer Analog Bus 0 to the data acquisition board. The other module must also be able to
