NI-9205/9206 Vendor Configuration Extensions

The following table lists the vendor configuration extensions for the NI-9205/9206.

Table 13. NI-9205/9206 Vendor Configuration Extensions
Index Sub Type R/W Description
0x2001 0 ARR:U32 — Scan List = 33
1 R Channels to Convert = <1..32>, default = 32
2..33 R/W Channel Code
0x2100 0 ARR:U32 — Calibration = 24
1 R Coeff3
2 R Coeff2
3 R Coeff1
4 R Coeff0
5 R 10 V Offset
6 R 10 V Gain
7 R 5 V Offset
... — —
13 R User Calibration, Coeff 3
... — —

NI-9205/9206 Scan List

The scan list channel codes consist of eight bit fields in a 32-bit entry.

Table 14. Scan List Format
Bits Field
31..24 = 0
23..16 Data Offset[t]
15..0 Conversion Code[t+2]

Bits <23..16> describe the data offset to store a conversion at time t, and bits <15..0> describe a complex conversion control code that takes effect two conversions in the future, at time t+2. The following table lists the conversion code NI-9205/9206.

Table 15. NI-9205/9206 Conversion Code
Bits Field
15..13 001 = Read AI
12..11 Bank:
  • 01 = Channels <0..15>
  • 10 = Channels <16..31>
10..8 Channel LSB = <0..7>
7..6 00 = Cal Pos Ref5V
5..4
  • 00 = NRSE
  • 11 = Cal Neg AI GND RSE or DIFF
3..2 Mode:
  • 01 = DIFF
  • 10 = Single-End A (Ch. <0..7>, <16..23>)
  • 11 = Single-End B (Ch. <8..15>, <24..31>)
1..0
  • 00 = ±10 V
  • 01 = ±5 V
  • 10 = ±1 V
  • 11 = ±200 mV
Table 16. NI-9205/9206 Scan List Format
Index Sub Type Value Sub Value
0x2001 0 ARR:U32 33 — —
1 32 — —
2 0x00002A38 18 0x00103238
3 0x00012B38 19 0x00113338
4 0x00022C38 20 0x00123438
5 0x00032D38 21 0x00133538
6 0x00042E38 22 0x00143638
7 0x00052F38 23 0x00153738
8 0x0006283C 24 0x0016303C
9 0x0007293C 25 0x0017313C
10 0x00082A3C 26 0x0018323C
11 0x00092B3C 27 0x0019333C
12 0x000A2C3C 28 0x001A343C
13 0x000B2D3C 29 0x001B353C
14 0x000C2E3C 30 0x001C363C
15 0x000D2F3C 31 0x001D373C
16 0x000E3038 32 0x001E2838
17 0x000F3138 33 0x001F2938

NI-9205/9206 Calibration Data

The NI-9205/9206 uses a quadratic formula for conversion from 16-bit raw data to calibrated data.

The NI-9205/9206 EEPROM provides overall polynomial values a3-a0 along with gain and offset values for each voltage range. Complete the following procedure to convert 16-bit raw data to calibrated data.

  1. Convert the 32-bit hex values to 64-bit floating point format for use in the calibration formula.
  2. Select the 32-bit gain value for a particular range.
  3. Select the 32-bit offset value (to be interpreted as a signed int) for a particular range.
  4. Use the above final coefficients and complete the following steps in the quadratic equation to convert raw 16-bit data into scaled volts:

    where f64(x) typecasts the value to a floating point:

    1. a0 = (f64(a0) × rangeGain) + rangeOffset
    2. a1 = f64(a1) × rangeGain
    3. a2 = f64(a2) × rangeGain
    4. a3 = f64(a3) × rangeGain
  5. Use the following formula with a3-a0 to obtain the scaled 16-bit value in volts, where x = signed un-scaled 16-bit data read from device:

    Scaled 16-bit signed data in volts = a3 × x3 + a2 × x2 + a1 × x + a0

Refer to NI-9201/9221 Vendor Configuration Extensions for information about how to decode the raw data using only the offset and gain values.