National Instruments FieldPoint FP-AI-112 User manual

FieldPoint™Operating Instructions
FP-AI-112 and cFP-AI-112
16-Channel, 16-Bit Analog Input Modules
These operating instructions describe how to install and use the
FP-AI-112 and cFP-AI-112 analog input modules (referred
to inclusively as the [c]FP-AI-112). For information about
configuring and accessing the [c]FP-AI-112 over a network, refer
to the user manual for the FieldPoint network module you are
using.
Features
The [c]FP-AI-112 is a FieldPoint analog input module with the
following features:
• 16 analog voltage input channels
• Eight voltage input ranges: 0–1 V, 0–5 V, 0–10 V, ±60 mV,
±300 mV, ±1V,±5V,and±10 V
• 16-bit resolution
• 50 and 60 Hz filter settings
• 250 Vrms CAT II continuous channel-to-ground isolation,
verified by 2,300 Vrms,1 minute dielectric withstand test
• –40 to 70 °C operation
• Hot swappable
Installing the FP-AI-112
The FP-AI-112 mounts on a FieldPoint terminal base (FP-TB-x),
which provides operating power to the module. Installing the
FP-AI-112 onto a powered terminal base does not disrupt the
operation of the FieldPoint bank.

FP-AI-112 and cFP-AI-112 2 ni.com
To install the FP-AI-112, 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-112).
2. Align the FP-AI-112 alignment slots with the guide rails on the
terminal base.
3. Press firmly to seat the FP-AI-112 on the terminal base. When
the FP-AI-112 is firmly seated, the latch on the terminal base
locks it into place.
Figure 1. Installing the FP-AI-112
Installing the cFP-AI-112
The cFP-AI-112 mounts on a Compact FieldPoint backplane
(cFP-BP-x), which provides operating power to the module.
Installing the cFP-AI-112 onto a powered backplane does not
disrupt the operation of the FieldPoint bank.
To install the cFP-AI-112, refer to Figure 2 and complete the
following steps:
1. Align the captive screws on the cFP-AI-112 with the holes on
the backplane. The alignment keys on the cFP-AI-112 prevent
backward insertion.
2. Press firmly to seat the cFP-AI-112 on the backplane.
1 I/O Module
2 Terminal Base
3 Alignment Slot
4Key
5 Latch
6 Guide Rails
1
3
2
4
5
6

© National Instruments Corp. 3 FP-AI-112 and cFP-AI-112
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
(10 lb ⋅in.) of torque. The nylon coating on the screws prevents
them from loosening.
Figure 2. Installing the cFP-AI-112
Wiring the [c]FP-AI-112
The FP-TB-xterminal base has connections for each of the
16 input channels and for an optional external power supply to
power field devices. The cFP-CB-xconnector block provides the
same connections. Each channel has one input terminal (VIN) for
voltage input. All 16 inputs are referenced to the COM terminals,
which are internally connected to each other and to the C terminals.
The channels share eight VSUP terminals, all of which are internally
connected to each other and to the V terminals.
1cFP-AI-112
2 Captive Screws
3 cFP Controller Module
4 Screw Holes
5 cFP Backplane
2
2
1
3 5
4
4

FP-AI-112 and cFP-AI-112 4 ni.com
You can use an external power supply to power field devices.
Connect the positive lead of the external power supply to both
V terminals and the negative lead to both C terminals. Ensure that
the current through both V terminals can never exceed 2 A.
Install 2 A maximum, fast-acting fuses between the external power
supply and the V terminals. The wiring diagrams in this document
show fuses where appropriate.
Table 1 lists the terminal assignments for the signals associated
with each channel. The terminal assignments are the same for the
FP-TB-xterminal bases and the cFP-CB-xconnector blocks.
Table 1. Terminal Assignments
Channel
Terminal Numbers
VIN VSUP COM
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
910 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

© National Instruments Corp. 5 FP-AI-112 and cFP-AI-112
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.
Measuring Voltage with the [c]FP-AI-112
Figure 3 shows how to connect a voltage source without an
external power supply to one channel of the [c]FP-AI-112.
Figure 3. Voltage Source without External Power Supply
Figure 4 shows how to connect a voltage source with an external
power supply to one channel of the [c]FP-AI-112.
Figure 4. Voltage Source with External Power Supply
V
SUP
V
IN
VC
>100 MΩ
Input
Impedance
COM
[c]FP-AI-112
Voltage
Source
+
–
Input
Circuitry
VSUP
VIN
VC
>100 MΩ
Input
Impedance
COM
[c]FP-AI-112
Input
Circuitry
Powered
Voltage
Transducer
OUT
+
–
+
–
External
Power Supply
(Optional)
2 A
Max

FP-AI-112 and cFP-AI-112 6 ni.com
Input Ranges
The input ranges for voltage signals are 0–1 V, 0–5 V, 0–10 V,
±60 mV, ±300 mV, ±1V,±5 V, and ±10 V. To prevent inaccurate
readings, choose an input range such that the signal you are
measuring does not exceed either end of the range. Signals that
greatly exceed the configured range can adversely affect
measurements on other channels.
Measurements on a channel may be invalid for up to one update
period after you change the input range.
Overranging
The [c]FP-AI-112 has an overranging feature that measures a little
beyond the nominal values of each range. For example, the actual
measurement limit of the ±10 V range is ±10.4 V. The overranging
feature enables the [c]FP-AI-112 to compensate for field devices
with span errors of up to +4% of full scale. Also, the overranging
feature helps prevent errors caused by clipping.
Filter Settings
Three filter settings are available for each channel. The filters
on the [c]FP-AI-112 input channels are comb filters that provide
notches of rejection at multiples, or harmonics, of a fundamental
frequency. You can select a fundamental frequency of 50, 60,
or 500 Hz. At the 50 and 60 Hz settings, the [c]FP-AI-112 applies
95 dB of rejection at the fundamental frequency and at least 60 dB
of rejection at each of the harmonics. In many cases, most of the
noise components of input signals are related to the local AC power
line frequency, so a filter setting of either 50 or 60 Hz is best.
The 500 Hz filter setting provides faster update rates but much less
accurate measurements.
Update Rate
The update rate of the [c]FP-AI-112 is determined by the filter
settings and the number of input ranges in use. Higher filter
settings and fewer input ranges yield faster update rates. Use the
following formula to determine the approximate update period:1
(number of channels with 50 Hz filter) ×0.061 s +
(number of input ranges with 50 Hz filter) ×0.12 s +
(number of channels with 60 Hz filter) ×0.051 s +
1 The update rate is the reciprocal of the update period.

© National Instruments Corp. 7 FP-AI-112 and cFP-AI-112
(number of input ranges with 60 Hz filter) ×0.10 s +
(number of channels with 500 Hz filter) ×0.007 s +
(number of input ranges with 500 Hz filter) ×0.012 s + 0.16 s
= Update Period
For the fastest performance, configure all unused channels for the
500 Hz filter setting and for an input range in use on one or more
other channels with the 500 Hz filter setting. For example, if
10 channels are configured for 0–10 V input and 500 Hz, four
channels are configured for 0–5 V and 60 Hz, and two channels
are unconnected, use the FieldPoint software to configure the
unconnected channels for 0–10 V input and 500 Hz filter setting.
Some combinations of two input ranges count as only one range for
calculating update rates. Those combinations are ±60 mV and
±300 mV; 0–1 V and 0–5 V; and ±1 V and ±5V.
The update rate does not affect the rate at which the network
module reads the data. Set up your application so that the update
rate is faster than the rate at which the network module polls the
[c]FP-AI-112 for data.
Status Indicators
The [c]FP-AI-112 has two green status LEDs, POWER and
READY. After you insert the [c]FP-AI-112 into a terminal base or
backplane and apply power to the connected network module, the
green POWER indicator lights and the [c]FP-AI-112 informs the
network module of its presence. When the network module
recognizes the [c]FP-AI-112, it sends initial configuration
information to the [c]FP-AI-112. After the [c]FP-AI-112 receives
this initial information, the green READY indicator lights and the
module is in normal operating mode.
Upgrading the FieldPoint Firmware
You may need to upgrade the FieldPoint firmware when you add
new I/O modules to the FieldPoint system. For information on
determining which firmware you need and how to upgrade your
firmware, go to ni.com/info and enter fpmatrix.

FP-AI-112 and cFP-AI-112 8 ni.com
Isolation and Safety Guidelines
Caution Read the following information before
attempting to connect the [c]FP-AI-112 to any circuits
that may contain hazardous voltages.
This section describes the isolation of the [c]FP-AI-112 and its
compliance with international safety standards. The field wiring
connections are isolated from the backplane and the inter-module
communication bus. The isolation barriers in the module provide
250 Vrms Installation Category II continuous isolation, verified by
2,300 Vrms, 1 minute dielectric withstand test. The [c]FP-AI-112
provides double insulation (compliant with IEC 61010-1) for
working voltages of 250 Vrms1. Safety standards (such as those
published by UL and IEC) require the use of double insulation
between hazardous voltages and any human-accessible parts or
circuits.
Never try to use any isolation product between human-accessible
parts (such as DIN rails or monitoring stations) and circuits that
can be at hazardous potentials under normal conditions, unless the
product is specifically designed for such an application, as is the
[c]FP-AI-112.
Even though the [c]FP-AI-112 is designed to handle applications
with hazardous potentials, follow these guidelines to ensure a safe
total system:
• There is no isolation between channels on the [c]FP-AI-112.
If a hazardous voltage is present on any channel, all channels
are considered hazardous. Make sure that all other devices and
circuits connected to the module are properly insulated from
human contact.
•Donot share the external supply voltages (the V and C
terminals) with other devices (including other FieldPoint
devices), unless those devices are isolated from human contact.
• For Compact FieldPoint, you must connect the protective earth
(PE) ground terminal on the cFP-BP-xbackplane to the system
safety ground. The backplane PE ground terminal has the
following symbol stamped beside it: . Connect the
backplane PE ground terminal to the system safety ground
1 Working voltage is defined as the signal voltage plus the common-mode voltage.
Common-mode voltage is the voltage of the module with respect to ground.

© National Instruments Corp. 9 FP-AI-112 and cFP-AI-112
using 14 AWG (1.6 mm) wire with a ring lug. Use the 5/16 in.
panhead screw shipped with the backplane to secure the ring
lug to the backplane PE ground terminal.
• As with any hazardous voltage wiring, make sure that all
wiring and connections meet applicable electrical codes and
commonsense practices. Mount terminal bases and backplanes
in an area, position, or cabinet that prevents accidental or
unauthorized access to wiring that carries hazardous voltages.
•Donot use the [c]FP-AI-112 as the only isolating barrier
between human contact and working voltages higher than
250 Vrms .
• Operate the [c]FP-AI-112 only at or below Pollution Degree 2.
Pollution Degree 2 means that only nonconductive pollution
occurs in most cases. Occasionally, however, a temporary
conductivity caused by condensation must be expected.
•Donot operate FieldPoint products in an explosive atmosphere
or where there may be flammable gases or fumes. If you need
to operate FieldPoint products in such an environment, the
FieldPoint products must be in a suitably rated enclosure.
• Operate the [c]FP-AI-112 at or below Installation Category II.
Installation Category II is for measurements performed on
circuits directly connected to the low-voltage installation.
This category refers to local-level distribution, such as that
provided by a standard wall outlet.
Specifications
The following specifications are typical for the –40 to 70 °C
temperature range and for 50 and 60 Hz filter settings unless
otherwise noted. Specifications are subject to change without
notice.
Input Characteristics
Number of channels .......................... 16
ADC resolution................................. 16 bits at 50 or 60 Hz;
10 bits at 500 Hz
(refer to table)
Type of ADC..................................... Delta-sigma

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Effective resolution by input range and filter setting
Update period and input bandwidth by filter setting
Normal-mode rejection..................... 95 dB
Nonlinearity ...................................... 0.0015% (monotonicity1
warranted over the operating
temperature range)
Input impedance (with power on)..... >100 MΩ
Overvoltage protection ..................... ±40 V
Input current
25 °C........................................... 400 pA typ, 1 nA max
70 °C........................................... 3 nA typ, 15 nA max
Nominal
Input Range
With
Overranging
Effective
Resolution*
at 50 or 60 Hz
Effective
Resolution*
at 500 Hz
±60 mV ±65 mV 3 µV25 µV
±300 mV ±325 mV 16 µV100 µV
±1 V ±1.04 V 40 µV300 µV
±5 V ±5.2 V 190 µV1500 µV
±10 V ±10.4 V 380 µV3000 µV
0–1 V 0–1.04 V 20 µV300 µV
0–5 V 0–5.2 V 95 µV1500 µV
0–10 V 0–10.4 V 190 µV3000 µV
*Includes quantization errors and typical rms noise.
Characteristic
Filter Settings
50 Hz 60 Hz 500 Hz
Update period*1.25–1.75 s 1.05–1.45 s 0.27–0.32 s
Input bandwidth (–3 dB) 13 Hz 16 Hz 130 Hz
* Applies when all 16 channels are set to the same filter setting. Refer to
the Update Rate section for information about calculating the update rate.
1 A characteristic of an ADC in which the digital code output always increases as the
value of the analog input to it increases.