Chapter 2
Analog Input Timing/Control
DAQ-STC Technical Reference Manual
2-48
©
National Instruments Corporation
To clear:
You must change the FIFO state by dealing with the
FIFO
All interrupts related to analog input are in interrupt group A.
To select the interrupt line to be used,
Interrupt_A_Output_Select = 0 through 7;
Interrupt_A_Enable = 1;
To determine quickly if any of the group A interrupts have occurred, use Interrupt_A_St.
Notes
To select interrupt output polarity, use Interrupt_Output_Polarity. This selection
depends on the board hardware design.
Pass_Through_0_Interrupt is also in interrupt group A.
For more detailed information about the conditions that generate an interrupt, refer to
section
.
2.6.9 Bitfield Descriptions
Bits in the register bit maps are organized into bitfields. A bitfield can contain one or more
bits. Only bits with contiguous locations within a register can belong to a bitfield. The high
and low pairs of load and save registers for 24-bit counters are also treated as bitfields. The
AITM-related bitfields are described below. Not all bitfields referred to in section
, are listed here. To locate a particular bitfield description within
this manual, refer to Appendix B,
.
AI_AIFREQ_Polarity
bit: 4
type: Write
in: AI_Personal_Register
address: 77
This bit selects the polarity of the AIFREQ output signal:
0: Active high.
1: Active low.
AI_Analog_Trigger_Reset
bit: 14
type: Strobe
in: AI_Command_1_Register
address: 8
This bit clears the hysteresis registers in the analog trigger circuit. Set this bit to 1 at the time
you arm the analog input counters if you want to use analog triggering in hysteresis mode for
any analog input signal. Before setting this bit to 1, make sure that the analog trigger is not
being used by any other part of the DAQ-STC. You should not set this bit to 1 in any other
case. This bit is cleared automatically.