NI 9436 Datasheet


1378
  • Screw Terminal connectivity
  • 250 V RMS, CAT II, channel-to-channel isolation
  • 250 V RMS, CAT II, channel-to-earth isolation
  • Protective backshell

The NI 9436 is an 8-channel, 20 ms sinking/sourcing digital input C Series module for any CompactDAQ or CompactRIO chassis. Each channel accepts signals from ±100 VDC to ±250 VDC and 100 VAC to 250 VAC. The NI 9436 works with industrial logic levels and signals to directly connect to a wide array of high voltage industrial switches, transducers, and devices.


1378

NI C Series Overview


1378

NI provides more than 100 C Series modules for measurement, control, and communication applications. C Series modules can connect to any sensor or bus and allow for high-accuracy measurements that meet the demands of advanced data acquisition and control applications.

  • Measurement-specific signal conditioning that connects to an array of sensors and signals
  • Isolation options such as bank-to-bank, channel-to-channel, and channel-to-earth ground
  • -40 °C to 70 °C temperature range to meet a variety of application and environmental needs
  • Hot-swappable

The majority of C Series modules are supported in both CompactRIO and CompactDAQ platforms and you can move modules from one platform to the other with no modification.

CompactRIO

1378

CompactRIO combines an open-embedded architecture with small size, extreme ruggedness, and C Series modules in a platform powered by the NI LabVIEW reconfigurable I/O (RIO) architecture. Each system contains an FPGA for custom timing, triggering, and processing with a wide array of available modular I/O to meet any embedded application requirement.

CompactDAQ

CompactDAQ is a portable, rugged data acquisition platform that integrates connectivity, data acquisition, and signal conditioning into modular I/O for directly interfacing to any sensor or signal. Using CompactDAQ with LabVIEW, you can easily customize how you acquire, analyze, visualize, and manage your measurement data.

1378

Software

LabVIEW Professional Development System for Windows
1378
  • Use advanced software tools for large project development
  • Generate code automatically using DAQ Assistant and Instrument I/O Assistant
  • Use advanced measurement analysis and digital signal processing
  • Take advantage of open connectivity with DLLs, ActiveX, and .NET objects
  • Build DLLs, executables, and MSI installers
NI LabVIEW FPGA Module
1378
  • Design FPGA applications for NI RIO hardware
  • Program with the same graphical environment used for desktop and real-time applications
  • Execute control algorithms with loop rates up to 300 MHz
  • Implement custom timing and triggering logic, digital protocols, and DSP algorithms
  • Incorporate existing HDL code and third-party IP including Xilinx IP generator functions
  • Purchase as part of the LabVIEW Embedded Control and Monitoring Suite
NI LabVIEW Real-Time Module
1378
  • Design deterministic real-time applications with LabVIEW graphical programming
  • Download to dedicated NI or third-party hardware for reliable execution and a wide selection of I/O
  • Take advantage of built-in PID control, signal processing, and analysis functions
  • Automatically take advantage of multicore CPUs or set processor affinity manually
  • Take advantage of real-time OS, development and debugging support, and board support
  • Purchase individually or as part of a LabVIEW suite

NI 9436 Circuitry


1378

  • The input signal on each digital input channel is first fully rectified by a diode bridge before passing through the current limiter and optoisolator. The output of each optoisolator is then passed through a smoothing filter.
  • The current limiter has a foldback response, where current will decrease with increasing input voltage. This ensures a low power dissipation at high voltage while maintaining high current at low voltage.
  • The optoisolator on each digital input channel provides isolation between the high voltage input circuitry and the low voltage digital circuitry.
  • The AC smoothing filter ensures a constant ON state for AC input signals.
  • Each input channel on the NI 9436 is individually isolated from one another and from other non-isolated system components and earth ground.

Digital Logic Levels

The NI 9436 measures whether the difference between the DIa and DIb pins is greater than or less than the digital logic levels. If the difference between the pins is within the input high range, the channel registers a HIGH. If the difference between the pins is within the input low range, the channel registers a LOW.

Input Current Limit

Each input on the NI 9436 has a current limiter with foldback response that varies with the input voltage. At lower input voltages, the input current level is higher and decreases with increasing input voltages. This is to maintain low power at high input voltages. The following figure shows the maximum and minimum input current per channel over the full temperature range that the NI 9436 present to a connected load in mA.

Figure 1. Input Current Per Channel

1378

Turn-Off Time

The NI 9436 turn-off time is the amount of time it takes for the current of the digital input to discharge any capacitance on the input line to a voltage below the turn-off threshold level when no signal is present or the sourcing-output device is open. When opening the sourcing-output device, the turn-off time is the time it takes for the NI 9436 to read the incoming voltage as OFF.
Note The NI 9436 turn-off time is the amount of time it takes for the DC input voltage to cross the DC turn-off threshold plus the input delay time of the NI 9436. The turn-off time with DC input voltage represents the maximum NI 9436 turn-off time .

The NI 9436 provides sinking digital inputs that discharge capacitance that might be present on the input line. If there are transients that could charge this capacitance to the value of the supply voltage, the turn-off time is the amount of time it takes to remove this charge to a level below the threshold voltage. When you debounce your readings from the NI 9436 in your software application with a debounce time that is at least as long as this turn-off time, the NI 9436 is immune to these capacitively-coupled transients.

Use the following equation to determine the correct maximum turn-off time over the full temperature range based on the supply voltage and the amount of capacitance in your system.
T=0.02−C×(V−55)(290⁢×V)−540000
where
  • T is the maximum turn-off time (s)
  • V is the system supply DC/peak voltage (VDC/Vpeak)
  • C is the capacitance in your system (nF)
Use the following equation to determine the maximum capacitance that your system can tolerate based on the supply voltage and desired turn-off time.
C=((0.02−T)×[(290×V)−540000]V−55)
where
  • C is the maximum capacitance (nF)
  • T is the desired turn-off time (s)
  • V is the system supply DC/peak voltage (VDC/Vpeak)
Figure 2. Capacitance Discharge

1378

  1. Capacitance from parts such as cables and sensors.