Table Of Contents

Designing Your System

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    Last Modified: July 30, 2021

    Complete the following steps to implement the Static Structural Test Reference Architecture design pattern for your specific test needs.

    1. Map your sensor list to NI instruments.
    2. Group modules into nodes.
    3. Group nodes into rings.
    4. Aggregate rings to a single port.
    5. (Optional) Adjust ring sizes.
    6. Select power supplies.
    7. Select network cables.
    8. Select power wiring.
    9. Select sensor wiring.
    10. Select the host PC.
    11. Select storage hardware.
    12. Select devices for analyst stations.

    Map Your Sensor List to NI Instruments

    Map your sensor list to the supported C series modules in the following table.

    Table 1. Supported C Series Modules
    Channel Type Model Description
    Quarter Bridge Strain NI-9235 8-Channel, 10 kS/s/channel, 120 Ω Quarter-Bridge Strain Gage, C Series Strain/Bridge Input Module
    NI-9236 8-Channel, 10 kS/s/channel, 350 Ω Quarter-Bridge Strain Gage, C Series Strain/Bridge Input Module
    Thermocouple NI-9213 16-Channel, 75 S/s Aggregate, ±78 mV C Series Temperature Input Module
    Voltage NI-9215 4-Channel, ±10 V, 100 kS/s/ch, 16-Bit, Simultaneous Input, C Series Voltage Input Module

    Group Modules Into Nodes

    Group your C Series modules into nodes.
    1. Arrange C Series modules into groups of up to eight and position them around the structure by optimizing total module count with the benefits of module proximity to the structure.
    2. Assign each group of C Series modules to one cDAQ-9189 TSN-enabled Ethernet CompactDAQ chassis to complete a single node.

    Group Nodes Into Rings

    Arrange your nodes into rings, as shown in the following figure.

    Figure 1. Ring Topology
    spd-note-note
    Note  

    The allowable distance between each node is equal to the maximum length of a CAT-5 cable (100 m).

    The maximum number of nodes per ring is dependent on the amount of cRIO-9805 Ethernet switches needed to aggregate the system. The maximum ring sizes are also based on the total number of nodes in the system. Design your rings within the limits in the following table.

    Total Nodes Maximum Nodes per Ring
    1-15 15
    16-18 9
    18-42 7
    spd-note-note
    Note  

    The maximum amount of nodes per ring reduces as total nodes in the system increase to account for the allowable amount of network hops in the TSN network. Refer to Figure 4 for more information.

    Aggregate Rings

    Aggregate the list of rings to a single port.

    The cRIO-9805 Ethernet switch can aggregate communication on up to three out of its four Ethernet ports. When arranging the cRIO-9805 devices, the two ports coming off of a ring must be connected to the same switch.

    Divide your ring list into pairs and aggregate each pair together according to the pattern in the following figure.

    Figure 2. Ring Pair Aggregation

    An additional cRIO-9805 can aggregate up to three ring pairs, as shown in the following figure. Use this recursive pattern to group rings until all ring communication aggregates to a single network port.

    Figure 3. Aggregation for Additional Ring Configurations

    (Optional) Adjust Ring Sizes

    You can adjust the ring sizes in your design so long as no two nodes are more than 15 hops apart.

    The TSN network can tolerate a maximum number of 15 hops between any two nodes in the network. When a cable or node fails within a ring, the remaining nodes in the ring reconfigure into two daisy chains. In a worst case scenario, a ring of N nodes could reconfigure into a daisy chain of N nodes.

    Figure 4. Network Hops Between Nodes After Network Cable Failure

    Select Power Supplies

    Select the power supplies for your nodes and the network aggregation subsystem. Each CompactDAQ chassis and Ethernet switch in your system needs its own DC power connection.

    Instead of using the dedicated power supply that ships with these components, you can consolidate AC power conversion into larger power supplies that distribute their DC outputs to multiple components in the system.

    Component Power Requirements

    The CompactDAQ chassis and Ethernet switch have the following power requirements per component:

    • cDAQ-9189 Chassis—16 W, 9 V to 30 V
    • cRIO-9805 Ethernet switch—5 W, 9 V to 30 V
    spd-note-note
    Note  

    The power requirement for the cDAQ-9189 includes maximum 1 W power load per slot across rated temperature. Quarter bridge strain gauge modules can draw close to 1 W depending on the use case. Refer to documentation for each component to create more sophisticated power budgets.

    Power Supply Options

    Refer to the following table to determine the best power supply option for your specific system design.

    Table 2. Supported Power Supplies
    Model Description
    PS-14 24 VDC, 3.3 A, 80 W DIN-Mountable Industrial Power Supply
    PS-15 24 VDC to 28 VDC, 5 A, 120 W, DIN-Mountable Industrial Power Supply
    PS-16 24 VDC to 28 VDC, 10 A, 240 W, DIN-Mountable Industrial Power Supply
    spd-note-note
    Note  

    For example, a single PS-15 can comfortably power six fully loaded CompactDAQ chassis and one Ethernet switch, and the PS-16 can comfortably power 13 fully loaded CompactDAQ chassis and three Ethernet switches.

    Select Network Cables

    Select the network cables needed for daisy chaining nodes and connecting rings to the Ethernet switches in the network aggregation subsystem.

    NI offers the following CAT-5E Ethernet cables in various lengths.

    Table 3. NI Ethernet Cables
    Model NI Part Number Length
    8-Pin Male Ethernet to 8-Pin Male Ethernet, CAT-5E Ethernet Cable 151733-0R3 0.3 M
    151733-01 1 M
    151733-02 2 M
    151733-05 5 M
    151733-10 10 M

    Select Power Wiring

    Select the power wiring for the cDAQ-9189 chassis and Ethernet switches.

    NI does not offer off-the-shelf cable assemblies for the CompactDAQ chassis or Ethernet switch. NI recommends using ferrules for stranded wires, and using the following wire gauge as defined in the specifications document for each model.

    Table 4. Power Wire Gauges
    Model Wire Gauge
    cDAQ-9189 24 AWG to 14 AWG
    cRIO-9805 24 AWG to 16 AWG

    Select Sensor Wires

    Select the sensor wiring for the C Series modules.

    NI does not offer off-the-shelf cable assemblies for sensors, and recommends the following wire gauges as defined in the specifications document for each model.

    Table 5. C Series Module Wire Gauges
    Model Wire Gauge
    NI-9213 28 AWG to 18 AWG copper conductor wire
    NI-9215 Screw-terminal: 16 AWG to 14 AWG copper conductor wire
    Spring-terminal: 30 AWG to 12 AWG copper conductor wire
    NI-9235 28 AWG to 18 AWG copper conductor wire
    NI-9236

    Select the Host PC

    Select a host PC for the server subsystem that meets the following minimum requirements:

    • 64 GB RAM
    • Intel Xeon E-2286G CPU 4.0 GHz, 6-Core
    • 2 Gigabit Ethernet adapters (one dedicated for instrumentation network)
    • Windows 10 64-bit
    • 30 GB minimum of free disk space
    • DHCP server support or an external DHCP-enabled router

    Select Storage Hardware

    Select the storage hardware to store data logs from your tests.

    Consider data throughput and test duration to choose storage hardware that is appropriately sized for your system needs.

    FlexLogger encodes all data into 8 byte data points, so 2,000 channels acquired at 100 S/s produces 1.6 MB/s of data.

    Refer to the following table for an example of how to determine the storage size needed for your system requirements.

    Table 6. Example of Data Throughput for 2,000 Channels Acquired at 100 S/s
    Data Throughput Redundant Logging
    1.6 MB/s 3.2 MB/s
    6 GB/hr 12 GB/hr
    140 GB/day 280 GB/day
    1 TB/week 2 TB/week

    Select Devices for Analyst Stations

    Select the devices to use for analyst stations.

    Consider the following recommendations to ensure the devices are compatible with the Static Data Viewer.

    • Multiple monitors—The Static Data Viewer can pop-out into multiple browser tabs for a single test; users can configure channels and alarms in one tab while displaying waveforms in another.
    • Browser—Google Chrome
    • Screen resolution—1440 x 900 pixels

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