National Instruments sbRIO-9218 User manual

GETTING STARTED GUIDE
sbRIO-9218
Non-Enclosed, 24-Bit, 51.2 kS/s/channel, 2-Channel C Series
Universal Analog Input Module
This document explains how to connect to the sbRIO-9218.
Note Before you begin, read the sbRIO-9218 Safety, Environmental, and
Regulatory Information document on ni.com/manuals and complete the software
and hardware installation procedures in your chassis documentation.
Note The guidelines in this document are specific to the sbRIO-9218. The other
components in the system might not meet the same safety ratings. Refer to the
documentation for each component in the system to determine the safety and EMC
ratings for the entire system.

sbRIO-9218 Pinout
V+ V–
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
2| ni.com | sbRIO-9218 Getting Started Guide

Table 1. Signals by Measurement Type
Mode Pin
1 2 3 4 5 6 7 8 9
±16 V EX+ — AI-,
EX- — — AI+ — — —
±65 mV EX+ 1— EX- 1— — AI+ AI-2— —
Full-
Bridge EX+ 1— EX- 1RS+ RS- AI+ AI- SC SC
IEPE — AI+ AI- — — — — — —
TEDS — T+ 3T- — — — — — —
Table 2. Signal Descriptions
Signal Description
AI+ Positive analog input signal connection
AI- Negative analog input signal connection
EX+ Positive sensor excitation connection
EX- Negative sensor excitation connection
1Optional sensor excitation.
2Tie to pin 3.
3TEDS Class 1 data connection.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 3

Table 2. Signal Descriptions (Continued)
Signal Description
RS+ Positive remote sensing connection
RS- Negative remote sensing connection
SC Shunt calibration connection
T+ TEDS data connection
T- TEDS return connection
4| ni.com | sbRIO-9218 Getting Started Guide

sbRIO-9218 Block Diagram
CH0
Isolation
Isolation
Vsup
sbRIO-9218
Input
Connector
Power
Connector
External
Power Supply
Measurement Type
Signal Conditioning
12 V
Excitation
IsolatorADC
CH1
Input
Connector
Measurement Type
Signal Conditioning
12 V
Excitation
IsolatorADC
Hardware Components
Software-Selectable
Externally Supplied Voltage
Legend
Data
• Two 24-bit analog-to-digital converters (ADCs) simultaneously sample both AI
channels.
• The sbRIO-9218 provides channel-to-channel isolation.
• The sbRIO-9218 reconfigures the signal conditioning for each measurement type.
• The sbRIO-9218 provides excitation for IEPE and bridge completion measurement
types.
• The sbRIO-9218 can provide optional 12 V sensor excitation for ±16 V, ±65 mV, and
±20 mA measurement types.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 5

±16 V and ±65 mV Signal Conditioning
AI+
AI- ADC
Amplifier
Overvoltage
Protection
Prefilter sbRIO-9218
Input signals on each channel are buffered, conditioned, and then sampled by an ADC.
6| ni.com | sbRIO-9218 Getting Started Guide

Full-Bridge Signal Conditioning
+ –
Reference
Input
AI+
EX+
RS+
AI–
EX–
RS–
SC
SC
sbRIO-9218
ADC
• The analog input connections sense then amplify the incoming analog signal.
• The excitation connections provide differential bridge-excitation voltage.
• Remote sensing continuously and automatically corrects for lead-wire induced
excitation voltage loss when using the RS connections.
• Shunt calibration can be used to correct for lead-wire induced desensitization of the
bridge.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 7

IEPE Signal Conditioning
2 mA
IEPE
Amplifier
and
Prefilter
AC Coupling
sbRIO-9218
+
–
ADC
AI+
AI-
• The incoming analog signal is referenced to an isolated ground.
• Each channel is configured for AC coupling with an IEPE current.
• Each channel provides a TEDS Class 1 interface.
±20 mA Signal Conditioning
AI+
DSUB
AI- ADC
Amplifier
Overvoltage
Protection
Current
Shunt
Prefilter sbRIO-9218
The NI-9983 provides a current shunt for the incoming analog signal.
8| ni.com | sbRIO-9218 Getting Started Guide

±60 V Signal Conditioning
AI+
DSUB
AI- ADC
Amplifier
Overvoltage
Protection
Prefilter sbRIO-9218
The NI-9987 provides an attenuator for the incoming analog signal.
Half-Bridge Signal Conditioning
+ –
Reference
Input
sbRIO-9218
ADC
DSUB
AI+
EX+
RS+
EX–
RS–
SC
SC
• The NI-9886 provides half bridge completion resistors for the incoming analog signal.
• You must connect AI+, EX+, and EX-.
• RS+ and RS- connections are optional.
• You do not need to connect the AI- signal because it is connected internally.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 9

Quarter-Bridge Mode Conditioning
+ –
Reference
Input
sbRIO-9218NI-9984/9985
ADC
DSUB
AI+
EXC
RC
The NI-9984 and NI-9985 provide a quarter-bridge completion resistor and half-bridge
completion resistors.
Measurement Types
The sbRIO-9218 provides built-in support for the following measurement types.
• ±16 V
• ±65 mV
• Full-Bridge
• IEPE
Tip NI recommends using the NI-9982 screw-terminal adapter when using built-
in measurement types on the sbRIO-9218.
The sbRIO-9218 provides additional support for the following measurement types when
using a measurement-specific adapter.
• ±20 mA, requires the NI-9983
• ±60 V, requires the NI-9987
10 | ni.com | sbRIO-9218 Getting Started Guide

• Half-Bridge, requires the NI-9986
• Quarter-Bridge, requires the NI-9984 (120 Ω) or NI-9985 (350 Ω)
±16 V Connections
EX+
VEX+
VEX-
VSUP+ VSUP-
sbRIO-9218
+
-
AI+
AI-/EX-
The sbRIO-9218 provides optional 12 V sensor excitation. To use the 12 V excitation,
connect a 9 V DC to 30 V DC power supply to Vsup, connect the excitation terminals on
your sensor to EX+/EX-, and enable 12 V excitation in your software.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 11

±65 mV Connections
EX+
EX-
VEX+
VEX-
VSUP+ VSUP-
sbRIO-9218
+
-
AI+
AI-
• You must connect AI- to EX- on the sbRIO-9218.
• The sbRIO-9218 provides optional 12 V sensor excitation. To use the 12 V excitation,
connect a 9 V DC to 30 V DC power supply to Vsup, connect the excitation terminals
on your sensor to EX+/EX-, and enable 12 V excitation in your software.
12 | ni.com | sbRIO-9218 Getting Started Guide

Full-Bridge Connections
RS+
EX+
AI+
AI–
EX–
RS–
SC
SC
sbRIO-9218
• The sbRIO-9218 provides 2 V excitation to loads ≥120 Ω or 3.3 V excitation to loads
≥350 Ω.
• The sbRIO-9218 provides optional connections for remote sensing (RS) and shunt
calibration (SC). Remote sensing corrects for errors in excitation leads and shunt
calibration corrects for errors caused by resistance within one leg of the bridge.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 13

IEPE Connections
sbRIO-9218
+
-
AI+
AI-
• The sbRIO-9218 provides an excitation current for each channel that powers IEPE
sensors.
• AI+ provides DC excitation and AI- provides the excitation return path.
±20 mA Connections
EX+
VEX+
VEX-
VSUP+ VSUP-
sbRIO-9218NI-9983
AI+
AI-
EX-
DSUB
14 | ni.com | sbRIO-9218 Getting Started Guide

• Connecting ±20 mA signals requires the NI-9983.
• The sbRIO-9218 provides optional 12 V sensor excitation. To use the 12 V excitation,
connect a 9 V DC to 30 V DC power supply to Vsup, connect the excitation terminals
on your sensor to EX+/EX-, and enable 12 V excitation in your software.
±60 V Connections
sbRIO-9218NI-9987
AI+
+
-AI-
DSUB
Connecting ±60 V signals requires the NI-9987.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 15

Half-Bridge Connections
sbRIO-9218NI-9986
DSUB
RS+
EX+
AI+
EX-
RS-
SC
SC
• Connecting half bridges requires the NI-9986.
• The sbRIO-9218 provides 2 V excitation to half bridges of ≥240 Ω total or 3.3 V
excitation to half bridges of ≥700 Ω total.
• The sbRIO-9218 provides optional connections for remote sensing (RS) and shunt
calibration (SC). Remote sensing corrects for errors in excitation leads and shunt
calibration corrects for errors caused by resistance within one leg of the bridge.
16 | ni.com | sbRIO-9218 Getting Started Guide

Quarter-Bridge Connections
sbRIO-9218NI-9984/9985
DSUB
RC
EXC
AI
• Connecting 120 Ω quarter bridges requires the NI-9984.
• Connecting 350 Ω quarter bridges requires the NI-9985.
Tip NI recommends 2 V excitation when using a NI-9984 with 120 Ω quarter
bridges and 3.3 V excitation when using the NI-9985 with 350 Ω quarter bridges.
TEDS Connections
TEDS
Enabled Sensor sbRIO-9218
T+
T-
Data
COM
For more information about TEDS, visit ni.com/r/rdteds.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 17

TEDS Support
TEDS Class 1 sensors provide an interface for transferring information from sensors. The
sbRIO-9218 and NI-9982F support TEDS Class 1 sensors.
Custom Cabling Guidelines
Observe the following guidelines when using the NI-9988 solder cup connector adapter to
create custom cables.
• Use a shielded cable for all signals.
• Connect the cable shield to earth ground.
• Use twisted-pair wiring for the AI+/AI- and RS+/RS- signals to achieve specified
EMC performance.
NI-9988
Shield
Sensor sbRIO-9218
AI+
AI-
RS+
RS-
AI+
AI-
RS+
RS-
Additional
Signals Additional Signals
DSUB
18 | ni.com | sbRIO-9218 Getting Started Guide

Opening a Measurement Adapter
What to Do
1 2
1. Unlock the measurement adapter housing/cover.
2. Slide the measurement adapter housing/cover to access the screw terminals.
Measurement Adapter Grounding
The ground terminals on a measurement adapter are connected to chassis ground when the
measurement adapter is connected to the sbRIO-9218 and the sbRIO-9218 is installed in a
chassis.
sbRIO-9218 Getting Started Guide | © National Instruments Corporation | 19