National Instruments FP-AI-111, CFP-AI-111 User Manual

FieldPoint Operating Instructions

FP-AI-111 and cFP-AI-111

16-Channel, 16-Bit Analog Milliamp
Input Modules

These operating instructions describe how to install and use the
National Instruments FP-AI-111 and cFP-AI-111 analog input
modules (referred to inclusively as the [c]FP-AI-111). For
information about configuring and accessing the [c]FP-AI-111
over a network, refer to the user manual for the FieldPoint network
module you are using.

Features

The [c]FP-AI-111 is a FieldPoint analog input module with the
following features:

• 16 single-ended analog current input channels

• Three input ranges: ±20, 0–20, and 4–20 mA

• 16-bit resolution

• Three filter settings: 50, 60, and 500 Hz

• Hot swappable

• 2,300 V

• –40 to 70 °C operation

transient overvoltage protection

rms

Installing the FP-AI-111

The FP-AI-111 mounts on a FieldPoint terminal base (FP-TB-x),
which provides operating power to the module. Installing the
FP-AI-111 onto a powered terminal base does not disrupt the
operation of the bank.

FieldPoint™, National Instruments™, NI™, and ni.com™ are trademarks of National Instruments Corporation.
Product and compa ny names mentioned herein are trade marks or trade names of their respe ctive companies.
For patents covering National Instruments products, refer to the appropriate location: Help»Patents in your software,
the

patents.txt file on your CD, or ni.com/p atents.

373281B-01 April 2003

© 2002–2003 National Instruments Corp. All rights reserved.

To install the FP-AI-111, refer to Figure 1 and complete the
following steps:

1. Slide the terminal base key to either position X, used for any
module, or position 1, used for the FP-AI-111 module.

2. Align the FP-AI-111 alignment slots with the guide rails on the
terminal base.

3. Press firmly to seat the FP-AI-111 on the terminal base. When
the module is firmly seated, the terminal base latch locks it into
place.

4

5

3

6

1

1 I/O Module
2Terminal Base
3 Alignment Slot

4Key
5Latch
6 Guide Rails

Figure 1. Installing the FP-AI-111

2

Installing the cFP-AI-111

The cFP-AI-111 mounts on a Compact FieldPoint backplane
(cFP-BP-x), which provides operating power to the module.
Installing the cFP-AI-111 onto a powered backplane does not
disrupt the operation of the bank.

To install the cFP-AI-111, refer to Figure 2 and complete the
following steps:

1. Align the captive screws on the cFP-AI-111 with the holes on
the backplane. The alignment keys on the cFP-AI-111 prevent
backward insertion.

2. Press firmly to seat the cFP-AI-111 on the backplane.

3. Using a number 2 Phillips screwdriver with a shank of at least
64 mm (2.5 in.) length, tighten the captive screws to 1.1 N ⋅ m

FP-AI-111 and cFP-AI-111 2 ni.com

(10 lb ⋅ in.) of torque. The nylon coating on the screws prevents
them from loosening.

3 5

2

2

1

1cFP-AI-111
2 Captive Screws
3 cFP Controller Module

Figure 2. Installing the cFP-AI-111

4 Screw Holes
5 cFP Backplane

Wiring the [c]FP-AI-111

4

4

The FP-TB-x terminal bases have connections for each of the
16 input channels on the FP-AI-111 and for an external supply to
power field devices. The cFP-CB-x connector blocks provide the
same connections for the cFP-AI-111.

Table 1 lists the terminal assignments for the signals associated
with each channel. The terminal assignments are the same for the
FP-TB-x terminal bases and the cFP-CB-x connector blocks.

© National Instruments Corp. 3 FP-AI-111 and cFP-AI-111

Table 1. Terminal Assignments

Terminal Numbers

Channel

0 1 17 18

1 2 17 18

2 3 19 20

3 4 19 20

4 5 21 22

5 6 21 22

6 7 23 24

7 8 23 24

8 9 25 26

9 10 25 26

10 11 27 28

11 12 27 28

12 13 29 30

13 14 29 30

14 15 31 32

15 16 31 32

I

in

V

SUP

COM

Each channel has one input terminal (Iin) for current input. All
16 current inputs are referenced to the COM terminals. If you are
using an external supply to power field devices, connect the power
supply to the V and C terminals of the terminal base or connector
block. Field devices source power from the V

and COM

SUP

terminals. Refer to the Measuring Current with the [c]FP-AI-111
section for detailed wiring diagrams.

Caution Cascading power between two modules defeats

isolation between those modules. Cascading power from
the network module defeats all isolation between
modules in the FieldPoint bank.

FP-AI-111 and cFP-AI-111 4 ni.com

Measuring Current with the [c]FP-AI-111

The [c]FP-AI-111 has 16 single-ended input channels. All
16 channels share a common ground reference that is isolated
from other modules in the FieldPoint system. Figure 3 shows the
analog input circuitry on one channel.

V

V

SUP

COM

I

IN

Filter

16-Bit

Isolated ADC

C

Figure 3. FP-AI-111 Analog Input Circuitry

The current input ranges are ±20, 0–20, and 4–20 mA. The input
channels have overcurrent protection up to ±30 mA. The
[c]FP-AI-111 reads current flowing into the I

terminal as positive

in

and current flowing out of the terminal as negative. Current flows
into the I

terminal, goes through a 100 Ω resistor, and flows out

in

from the COM or C terminal.

Figure 4 shows how to connect a current source without an external
power supply to one channel of the [c]FP-AI-111.

VC

V

Current

Source

SUP

COM

I

IN

To Analog

Input Circuitry

100 Ω

To Next Channel

FP-AI-111

Figure 4. Current Source without External Power Supply

© National Instruments Corp. 5 FP-AI-111 and cFP-AI-111