Chapter 2
Analog Input Timing/Control
©
National Instruments Corporation
2-71
DAQ-STC Technical Reference Manual
AI_SI_Write_Switch
bit: 3
type: Write
in: AI_Mode_2_Register
address: 13
This bit enables the write switch feature of the SI load registers. Writes to SI load register A
are:
0: Unconditionally directed to SI load register A.
1: Directed to the inactive SI load register.
AI_SI2_Arm
bit: 12
type: Strobe
in: AI_Command_1_Register
address: 8
Setting this bit to 1 arms the SI2 counter. The counter remains armed and the bit remains set
until it is disarmed, either by hardware or by setting AI_Disarm to 1. Related bitfields:
AI_SI2_Armed_St, AI_Disarm.
AI_SI2_Armed_St
bit: 11
type: Read
in: AI_Status_2_Register
address: 5
This bit indicates whether the SI2 counter is armed:
0: Disarmed.
1: Armed.
Related bitfields: AI_SI2_Arm.
AI_SI2_Initial_Load_Source
bit: 9
type: Write
in: AI_Mode_2_Register
address: 13
This bit selects the initial SI2 load register:
0: Load register A.
1: Load register B.
Do not change this bit while the counter is counting.
AI_SI2_Load
bit: 11
type: Strobe
in: AI_Command_1_Register
address: 8
If the SI2 counter is disarmed, this bit loads the SI2 counter with the contents of the selected
SI2 load register (A or B). If the SI2 counter is armed, writing to this bit has no effect. This
bit is cleared automatically.
AI_SI2_Load_A
bits: <0..15>
type: Write
in: AI_SI2_Load_A_Register
address: 23
This bitfield is load register A for the SI2 counter. If load register A is the selected SI2 load
register, the SI2 counter loads the value contained in this bitfield on AI_SI2_Load and on
SI2_TC. Related Bitfields: AI_SI2_Next_Load_Source_St, AI_SI2_Load.