1. Four Steps to Deterministic Distributed I/O
|Step 1. Select Your EtherCAT Master||Step 2. Select Your EtherCAT Slave|
|Step 3. Select Your C Series I/O Modules||Step 4. Select Your Development Software|
2. Step 1. Select Your EtherCAT Master
Use one of the following NI real-time programmable automation controllers (PACs) with two Ethernet ports as the EtherCAT master for your distributed system.
|Controller Platform||EtherCAT Master||Description||Additional Hardware|
|CompactRIO||NI cRIO-908x RT||High-performance, rugged, real-time PACs||-|
|NI cRIO-902x||Ultrarugged, real-time PACs|
|NI cRIO-9074||High-value, integrated real-time controller and chassis||-|
|PXI||All real-time embedded PXI controllers1||Gigahertz-range, dual-core processors with LabVIEW Real-Time and local I/O slots||NI PXI-8231, PXI-8232, or PXI-8234 Ethernet interface2|
|Industrial Controller||All real-time NI industrial controllers||Rugged, high-performance, fanless industrial controllers with LabVIEW Real-Time||-|
|Embedded Vision System||All real-time EVS||Multicore, fanless, rugged automated controller with multiple camera connectivity||-|
1Does not include the NI 8353 real-time rack-mount controller
2Only required if the PXI controller does not have two Ethernet ports
3. Step 2. Select Your EtherCAT Slave
The NI 9144 modular slave adds expansion EtherCAT I/O to your CompactRIO, PXI, or industrial controller system. With its two Ethernet ports, you can daisy chain multiple NI 9144 devices from a single master to expand their time-critical applications while maintaining hard determinism with minimal processor resources. With a temperature range of -40 to 70 °C and 50 g shock ratings, this rugged slave chassis is designed for industrial applications.
Figure 1. NI 9144 Slave Chassis
NI 9144 Slave Chassis for EtherCAT
4. Step 3. Select Your C Series I/O Modules
Because the NI 9144 chassis is an 8-slot modular slave, you have the flexibility to customize your measurement types and channels by plugging in additional I/O modules. Plus, attaching another modular chassis adds even more I/O slots to your system. Not only are all I/O modules automatically synchronized in each chassis, but all the NI 9144 slave chassis in the network are synchronized with each other as well.
The NI 9144 expansion chassis is compatible with all C Series modules that are programmable with the NI LabVIEW FPGA Module. Also, you can program more than 40 analog and digital C Series modules with the easy-to-use CompactRIO Scan Mode in the LabVIEW Real-Time Module. For a full list of modules, see the C Series Module Compatibility Chart.
Figure 2. C Series I/O Modules With Sensor-Specific Connectors, Built-In Signal Conditioning, and High-Performance A/D Converters
5. Step 4. Select Your Development Software
The LabVIEW graphical development environment is designed for engineers and scientists who need to create flexible and scalable test, measurement, and control applications rapidly and at minimal cost. The intuitive graphical development environment provides convenient software tools you need for easily adding EtherCAT I/O to your system. The LabVIEW Real-Time Module offers easy access to the physical channels using the click-and-drag I/O variable, live test panels, and I/O forcing for troubleshooting. The LabVIEW FPGA Module helps you program the field-programmable gate arrays (FPGAs) on the NI 9144 and its modules for high-speed and customizable I/O timing, triggering, and control. Plus, using LabVIEW FPGA paves the way for domain experts to quickly prototype and implement their ideas without having to be a VHDL programmer.
Adding programmable FPGA capabilities to EtherCAT I/O opens the doors to a whole new level of customization and flexibility for your application. For example, embedding decision-making capabilities at the node reduces response time, allowing the chassis to quickly react to the environment without host interaction. The intelligent slave device can also offload processing from the master controller by conducting inline analysis, custom triggering, and signal manipulation before sending the results back. For example, you can use the NI 9234 dynamic signal acquisition module to take audio frequency measurements on the NI 9144 EtherCAT slave. The FPGA on the NI 9144 can acquire this high-speed waveform data, perform fast Fourier transform (FFT) and other analysis, and then send back to the master the single-point results on whether particular frequencies were found.
Figure 3. LabVIEW Graphical Development Environment
|Software||Version for Programming in LabVIEW Real-Time Only||Version for Programming in LabVIEW Real-Time and LabVIEW FPGA|
|LabVIEW||8.6 or later||2009 or later|
|LabVIEW Real-Time Module||8.6 or later||2009 or later|
|LabVIEW FPGA Module||–||2009 or later|
|NI-RIO driver software||3.0.1 or later||3.2.1 or later|
|NI-Industrial Communications for EtherCAT driver software||1.0 or later||1.1 or later|
Table 1. Supported LabVIEW and Driver Versions