Deterministic Ethernet Expansion Chassis User's Guide

one conversion in the future, at time t+1. The conversion code is listed in

Table 29.

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 30 contains the default scan list.

NI 9217 Calibration Data

The NI 9217 has four RTD channels that can measure 100 Ω RTD in 3-wire

and 4-wire mode. There is a 1 mA excitation current source per channel and

the module range is –500 Ω to 500 Ω. The resistance range specified in the

manual is 0 to 400 Ω. This range is tested and covers the temperature range

of –200 ºC to 850 ºC for the standard platinum RTD. The channel does not

read negative resistance.

Each channel has an associated LSB weight, which is the number of

Ω per bit, and an offset, which is the number of Ω per bit measured when

the inputs are grounded.

Table 29. NI 9217 Conversion Code

Bits Field

7:3 Conversion rate: 0b11111 = 31,

High-Accuracy

0b00010 = 2, High-Speed

2:1 Channel number

0 Reserved

Table 30. NI 9217 Scan List Format

Index Sub Type Value

0x2001 0 ARR:U32 5

1 4

2 0x0000 | 0xF8 | 0x02

3 0x0100 | 0xF8 | 0x04

4 0x0200 | 0xF8 | 0x06

5 0x0300 | 0xF8 | 0x00