National Instruments cFP-RTD-124 User Manual download pdf (Page 4)

FP-RTD-124 and cFP-RTD-124 4 ni.com

Wiring the [c]FP-RTD-124

The FP-TB-x terminal bases have connections for each of the eight

input channels on the FP-RTD-124. The cFP-CB-x connector

blocks provide the same connections for the cFP-RTD-124.

Table 1 lists the terminal assignments for the signals associated

with each channel.

If you are using shielded wiring, you can reduce input signal noise

by connecting one end of the shield to the COM terminal. Do not

connect the shield to any of the wires at the signal end.

Taking RTD Measurements

with the [c]FP-RTD-124

The [c]FP-RTD-124 has eight input channels. All eight channels

share a common ground that is isolated from other modules in the

FieldPoint system. Each channel pulses a 2 mA excitation current

out of the EXCITE+ terminal. The excitation current returns

through the COM terminal. The SENSE+ and SENSE– terminals

measure resistance and compensate for lead resistance errors. Each

channel is filtered, then sampled by a 16-bit analog-to-digital

converter.

Table 1. Terminal Assignments

Channel

Terminal Numbers

SENSE+ SENSE– EXCITE+ COM

0 1 2 17 18

1 3 4 19 20

2 5 6 21 22

3 7 8 23 24

4 9 10 25 26

5 11 12 27 28

6 13 14 29 30

7 15 16 31 32

1 2 3 4 5 6 7 8 9 ... 14 15

No comments

National Instruments cFP-RTD-124 User Manual Page 4