Chapter 2
Analog Input Timing/Control
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National Instruments Corporation
2-77
DAQ-STC Technical Reference Manual
AI_START1_Edge
bit: 5
type: Write
in: AI_Trigger_Select_Register
address: 63
This bit enables edge detection of the START1 trigger:
0: Disabled (level-sensitive trigger).
1: Enabled (edge-sensitive trigger).
You should normally set this bit to 1. You must set this bit to 1 if AI_START1_Select is set
to 0. You should set this bit to 0 if the ASIC is a START1 slave to another DAQ-STC.
AI_START1_Interrupt_Ack
bit: 9
type: Strobe
in: Interrupt_A_Ack_Register
address: 2
Setting this bit to 1 clears AI_START1_St and acknowledges the START1 interrupt request
(in either interrupt bank) if the START1 interrupt is enabled. This bit is cleared automatically.
Related bitfields: AI_START1_St.
AI_START1_Interrupt_Enable
bit: 1
type: Write
in: Interrupt_A_Enable_Register
address: 73
This bit enables the START1 interrupt:
0: Disabled.
1: Enabled.
The START1 interrupt is generated on valid START1 triggers received by the DAQ-STC. A
valid START1 trigger is one that is received while the SC counter is armed and in the WAIT1
state.
AI_START1_Polarity
bit: 15
type: Write
in: AI_Trigger_Select_Register
address: 63
This bit determines the polarity of the START1 trigger:
0: Active high or rising edge.
1: Active low or falling edge.
You should set this bit to 0 if AI_START1_Select is set to 0. Related bitfields:
AI_START1_Select.
AI_START1_Pulse
bit: 0
type: Strobe
in: AI_Command_2_Register
address: 4
Setting this bit to 1 sends a START1 trigger to the counters if the START1 software strobe is
selected (AI_START1_Select is set to 0). This bit is cleared automatically. Related bitfields:
AI_START1_Select.