Product Overview
The National Instruments cDAQ-9191 is a single slot CompactDAQ chassis with both Ethernet and wireless connectivity. It accepts one C Series I/O module and connects that module to a host computer over a wired or wireless network. The chassis is designed for distributed measurement where a small number of signals must be acquired in a location that is difficult to reach with cabling.
The cDAQ-9191 is part of the NI CompactDAQ platform, which is known for modular signal conditioning and quick system assembly. Engineers select a C Series module for the signal type they need, install it in the chassis, and configure the system in software. The chassis handles communication with the host and provides power and timing resources for the installed module.
Single Slot Modular I/O
The chassis accepts one C Series module. This single slot design is useful when a measurement point requires only one signal type, such as a few analog inputs, a set of thermocouples, or a group of digital lines. By placing the chassis near the sensor, cable runs can be shortened and noise pickup reduced compared with routing every signal back to a central cabinet.
Module selection determines the channel count, resolution, isolation, and sampling capability of the system. Engineers should confirm that the chosen module is supported by the chassis and by the installed software version. Because the module is recognized by the driver, configuration and scaling can be handled in the same application that manages other NI hardware.
Ethernet and Wireless Communication
The cDAQ-9191 supports Ethernet and wireless communication. Ethernet provides a stable wired connection when cabling is practical, while wireless connectivity allows measurement in locations where running network cable is difficult or costly. Engineers can choose the connection method that best fits the installation.
Wireless communication requires attention to network security, signal strength, and interference. Engineers should configure encryption and access control, verify coverage at the installation point, and test data throughput under realistic conditions. Local buffering in the chassis and driver helps smooth short interruptions, but sustained data rates should be validated for the application.
Timing and Synchronization
The chassis provides timing resources for the installed C Series module and supports synchronization with other NI hardware where the system architecture allows. Hardware timed acquisition and triggering can be used to align measurements with external events. Engineers should document the sample clock source and trigger configuration so that the test sequence can be reproduced.
In wireless systems, timing and data transfer can be affected by network conditions. Engineers should review the supported synchronization methods for the specific modules and software version, and should plan test sequences that tolerate normal network variability without compromising measurement validity.
Installation and Environmental Considerations
The cDAQ-9191 is designed for bench top and industrial use. It should be mounted where airflow is adequate and where the operating temperature range is respected. The chassis should be protected from moisture, dust, and excessive vibration beyond its ratings. Cable routing should avoid strain on connectors and should keep signal cables away from high current power conductors.
Proper grounding and shielding help maintain measurement quality. Engineers should follow the module and chassis documentation for shield termination and grounding. In industrial cabinets, DIN rail mounting and organized cable management improve serviceability and reduce the chance of accidental damage during maintenance.
Typical Applications
Distributed measurement in difficult to cable locations
Remote sensor monitoring over Ethernet or wireless
Bench top data acquisition with modular I/O
Machine mounted measurement points
Laboratory test setups with changing signal types
Small channel count systems in industrial cabinets
The cDAQ-9191 provides a single slot CompactDAQ chassis with Ethernet and wireless connectivity. Its compact size and modular I/O make it suitable for distributed measurement applications where a small number of signals must be acquired in flexible locations.
