CompactRIO Considerations
- Updated2024-10-22
- 4 minute(s) read
CompactRIO Considerations
This section contains information on using the following CompactRIO and CompactRIO single-board controllers with NI-DAQmx:
- cRIO-9040, 9041, 9042, 9043, 9045, 9046, 9047, 9048, 9049, 9053, 9054, 9055, 9056, 9057, and 9058 controllers.
- sbRIO-9603, 9608, 9609, 9628, 9629, and 9638 controllers.
Slot Program Mode
In MAX, when you add a C Series module to a CompactRIO controller there are three program modes to choose from.
- Real-Time (NI-DAQmx)
- Real-Time Scan
- LabVIEW FPGA
In order for DAQmx to communicate with the module, the module must be in Real-Time (NI-DAQmx) mode.
Hardware Timed Single Point Sample Mode
The CompactRIO controllers support hardware timed single point (HWTSP) sample mode with a few caveats.
- The NI 9260 does not support HWTSP.
- The NI 9361 does not support HWTSP.
- C Series Scanned Devices do not default to the lowest latency mode. They default to a slower convert rate to allow more time for settling. This behavior limits the maximum HWTSP acquisition rate of the module to allow more time for settling. If you prefer, you can configure the module for a faster acquisition rate with less time for settling. For additional information, see Sampling Rate Considerations.
Model Names
CompactRIO may use slightly different C Series model names and product IDs compared to CompactDAQ. For CompactRIO, see C Series Module IDs on ni.com.
Timing Considerations
CompactRIO controllers handle sampling rate and the default value for the hardware-timed mode differently than CompactDAQ chassis.
In a CompactRIO or Single-Board RIO controller with C Series Slow Sample devices, such as the NI 9211, if the sampling rate of a hardware-timed acquisition exceeds the maximum sampling rate of the module, DAQmx generates warning or errors. When a Slow Sample device is in the same task as a non-Slow Sample device, exceeding the maximum sampling rate of the Slow Sample device results in the most recently acquired sample being read multiple times. In this scenario, the first sample of a hardware-timed acquisition with C Series Slow Sample devices is sampled when the task is committed.
Default Settings for the AI.ADCTimingMode Attribute/Property
For all modules in the CompactRIO and Single-Board RIO controllers, the default value in hardware-timed mode is automatically determined based on Sample Clock Rate.
Shared Trigger Bus
On the CompactRIO and CompactRIO Single-Board controllers, NI-DAQmx provides a simple trigger bus between LabVIEW FPGA and NI-DAQmx with the following characteristics:
CompactRIO[1]1 cRIO-9040, 9041, 9042, 9043, 9045, 9046, 9047, 9048, 9049, 9053, 9054, 9055, 9056, 9057, and 9058 | CompactRIO Single-Board[2]2 sbRIO-9603, 9608, 9609, 9628, 9629, and 9638 |
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- Change detection event exported from a buffered change detection DI task
- Sample clock exported from a hardware-timed digital input or output task running faster than 3.5 MHz
Counter output event exported from a counter task that configures its output behavior to pulse
In This Section
Related Information
- CompactRIO Timing Engines
- CompactDAQ, CompactRIO, and TestScale Simultaneous Tasks
- Time-Based Features for Network-Synchronized Devices
Network-synchronized devices feature automatic network-based synchronization when connected together across a compatible network. When these devices are synchronized across a compatible network all device timebases, time triggers, and timestamps will automatically be synchronized.
- Software Support for CompactRIO and CompactDAQ
- Sampling Rate Considerations
- C Series Scanned Devices
- C Series Module IDs
- Configurable Timing for C Series Devices
- C Series Device Groupings
- Immediate Routing
- Task-Based Routing
- Lazy Line Transitions