National Instruments NI-9361 Manual

NI-9361

CALIBRATION PROCEDURE
NI 9361
8-Channel Counter Input Module
This document contains the verification procedure for the NI 9361. For more information
about calibration solutions, visit ni.com/calibration.
Contents
Software.................................................................................................................................... 1
Documentation.......................................................................................................................... 1
Test Equipment..........................................................................................................................2
Test Conditions..........................................................................................................................2
Initial Setup............................................................................................................................... 3
Verification................................................................................................................................3
Accuracy Under Calibration Conditions...................................................................................5
Worldwide Support and Services.............................................................................................. 5
Software
Calibrating the NI 9361 requires the installation of NI-DAQmx 14.5 or later on the calibration
system. You can download NI-DAQmx from ni.com/downloads. NI-DAQmx supports
LabVIEW, LabWindows™/CVI™, ANSI C, and Microsoft Visual Basic .NET. When you install
NI-DAQmx, you only need to install support for the application software that you intend to
use.
Documentation
Consult the following documents for information about the NI 9361, NI-DAQmx, and your
application software. All documents are available on ni.com and help files install with the
software.
NI cDAQ-9174/9178 Quick Start
NI-DAQmx installation and hardware setup
NI 9361 Getting Started Guide
NI 9361 specific information

NI 9361 Datasheet
NI 9361 specifications and calibration interval
NI-DAQmx Readme
Operating system and application software support in NI-DAQmx
NI DAQmx Help
Information about creating applications that use the NI-DAQmx driver
LabVIEW Help
LabVIEW programming concepts and reference information about NI-DAQmx VIs
and functions
NI-DAQmx C Reference Help
Reference information for NI-DAQmx C functions and NI-DAQmx C properties
NI-DAQmx .NET Help Support for Visual Studio
Reference information for NI-DAQmx .NET methods and NI-DAQmx .NET
properties, key concepts, and a C enum to .NET enum mapping table
Test Equipment
The following table lists the equipment recommended for the performance verification
procedure. If the recommended equipment is not available, select a substitute using the
requirements listed.
Table 1. Recommended Equipment
Equipment Recommended Model Requirements
Frequency Standard NI PXIe-6674T,
NI PXIe-6614, or
Keysight 33250A
A highly stable clock source that is
able to generate 1 MHz, 5 V TTL
output with ≤±5 ppm total accuracy
Chassis NI cDAQ-9178 —
Connection
Accessory
NI 9923 —
Test Conditions
The following setup and environmental conditions are required to ensure the NI 9361 meets
published specifications.
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• Keep connections to the NI 9361 as short as possible. Long cables and wires act as
antennas, picking up extra noise that can affect measurements.
• Verify that all connections to the NI 9361 are secure.
• Maintain an ambient temperature of 23 °C ± 5 °C. The NI 9361 temperature will be
greater than the ambient temperature.
• Keep relative humidity below 80%.
Initial Setup
Refer to the NI cDAQ-9174/9178 Quick Start for information about how to install the software
and hardware and how to configure the device in Measurement & Automation Explorer
(MAX).
Note When a device is configured in MAX, it is assigned a device name. Each
function call uses this device name to determine which device to calibrate. This
document uses Dev_name to refer to the device name. In the following procedures,
use the device name as it appears in MAX.
Complete the following steps to set up the NI 9361.
1. Install NI-DAQmx.
2. Make sure the NI cDAQ-9178 power source is not connected.
3. Connect the NI cDAQ-9178 to the system safety ground.
a) Attach a ring lug to a 14 AWG (1.6 mm) wire.
b) Connect the ring lug to the ground terminal on the side of the NI cDAQ-9178 using
the ground screw.
c) Attach the other end of the wire to the system safety ground.
4. Install the module in slot 8 of the NI cDAQ-9178 chassis. Leave slots 1 through 7 of the
NI cDAQ-9178 chassis empty.
5. Connect the NI cDAQ-9178 chassis to your host computer.
6. Connect the power source to the NI cDAQ-9178 chassis.
7. Launch MAX.
8. Right-click the device name and select Self-Test to ensure that the module is working
properly.
Verification
The following performance verification procedure describes the sequence of operation and
provides test points required to verify the NI 9361. The verification procedure assumes that
adequate traceable uncertainties are available for the calibration references.
Base Clock Accuracy Verification
Complete the following procedure to determine the As-Found status of the NI 9361.
1. Connect the Frequency Standard to the NI 9361 as shown in the following figure. Use the
NI 9923 to make the connections.
NI 9361 Calibration Procedure | © National Instruments | 3

Figure 1. Base Clock Accuracy Verification Connections
OUT
GND
NI 9361
DI-
Frequency
Standard DI+
COM
2. Acquire a Base Clock Accuracy sample.
a) Configure the NI 9361 in single-ended mode with the settings in Table 2.
b) Configure the Frequency Standard with the settings in Table 3.
c) Start task.
d) Wait at least 20 ms after starting the acquisition before reading the data in order to
provide time for the measurement to become valid.
e) Read the measurement value for the Base Clock Accuracy.
f) Compare the Base Clock Accuracy measurement to the test limits in Table 4.
Table 2. NI 9361 Configuration
Test
Points
NI 9361 Settings
Counter
Channel
Measurement
Type
Measurement
Method
Measurement
Time
Divisor Maximum
Measurable
Period
1 MHz ctr0 Frequency Dynamic
Averaging
0 10,000 0
Note To configure Measurement Time, Divisor, and Maximum Measurable
Period, you must explicitly set these properties with the DAQmx Channel
Property Node after calling DAQmx Create Channel.
Table 3. Frequency Standard Settings
Frequency Format Duty Cycle
1 MHz TTL 50%
Table 4. NI 9361 Base Clock Accuracy Verification Test Limits
Test Point Lower Limit Upper Limit
1,000,000 Hz 999,950 Hz 1,000,050 Hz
If the Base Clock Accuracy verification procedure determines that the NI 9361 is outside
of the limits, refer to Worldwide Support and Services for assistance in returning the
device to NI.
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Accuracy Under Calibration Conditions
The following accuracy table is valid for calibration under the following conditions:
• Ambient temperature of 23 °C ± 5 °C
• NI 9361 installed in slot 8 of an NI cDAQ-9178 chassis
• Slots 1 through 7 of the NI cDAQ-9178 chassis are empty
Table 5. NI 9361 Base Clock Accuracy
Test Point Specification Limit
1 MHz 50 ppm
Note For operational specifications, refer to the most recent NI 9361 Datasheet
online at ni.com/manuals.
Worldwide Support and Services
The National Instruments website is your complete resource for technical support. At ni.com/
support, you have access to everything from troubleshooting and application development
self-help resources to email and phone assistance from NI Application Engineers.
Visit ni.com/services for NI Factory Installation Services, repairs, extended warranty, and
other services.
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provide up-to-date contact information, support phone numbers, email addresses, and current
events.
NI 9361 Calibration Procedure | © National Instruments | 5

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