NI 9144 User Guide and Specifications
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© National Instruments
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47
NI 9217 Conversion Speed Control
The NI 9217 converts at two pre-defined rates, as controlled by the speed control field.
Note
The conversion rate assumes that 4 channels are in the scan list.
NI 9217 Scan List
The scan list channel codes consist of three bit fields in a 32-bit entry.
Bits <15..8> describe the data offset to store a conversion at time
t
, and bits <7..0> describe the
conversion control codes that take effect one conversion in the future, at time
t
+2. The
conversion code is listed in Table 44.
Note
The conversion rate for every channel must match the value of the conversion
speed control in 0x2002.
For example, the scan list entry 0x00000001FC indicates this scan stores at address 1, and the
next conversion is channel 2 at high-accuracy.
Table 42.
NI 9217 Conversion Speed Control
Speed Control
Meaning
Conversion Rate
31 (0x1F)
High-Accuracy
200 ms/channel (800 ms total)
2 (0x02)
High-Speed
2.5 ms/channel (10 ms total)
Table 43.
NI 9217 Conversion Code
Bits
Field
31..16
Reserved
15..8
Data Offset[t]
7..0
Convert Code [t=1]
Table 44.
NI 9217 Conversion Code
Bits
Field
7..3
Conversion rate:
0b11111 = 31, High-Accuracy
0b00010 = 2, High-Speed
2..1
Channel number
0
Reserved
