National Instruments SCXI-1126 Frequency Input Module

The SCXI-1126 (Part Number: 776572-26) is an isolated Frequency Input Module from the SCXI Series by NI. All eight channels on this module have a frequency-to-voltage conversion circuit with programmable input range, threshold, hysteresis, and filtering. The channels have ten selectable input frequency ranges from 250 kHz-128 kHz. Every channel additionally has four selectable, 4-pole lowpass filters with cut-off frequencies from 1Hz-1 kHz. The output voltages are multiplexed onto one channel of a DAQ instrument. Thus, the user can scan and obtain numerous frequency and analog input signals within one high-speed scan operation. The NI SCXI-1126 is suitable for isolating frequency generating sensors, and other types of analog and digital periodic signal sources. The device is equipped with a 50-pin male ribbon cable rear connector and 32-pin male DIN C front I/O connector.

This Frequency Input Module operates with digital and analog input signals to 250 V maximum. The SCXI 1126 is fully software programmable, which allows the user to configure the frequency input range, threshold level, hysteresis level, and output filtering for every channel. The input stage of every channel is separate from the other channels and from the chassis, to 250 Vrms maximum. Every channel is additionally safe from input overvoltages, to 250 Vrms maximum while powered on or off. The isolated analog input stage is comprised of a trigger circuit that compares the input waveform to a user-programmed threshold and hysteresis. The NI device is run using the NI-DAQmx driver software which is compatible with software packages/application development environments (ADEs) such as LabVIEW, LabWindows/CVI, or Measurement Studio. The device hardware can be configured using the Measurement & Automation Explorer tool.

Since there are low bandwidths on the output filters, the user must wait about three seconds after modifying the settings to enable the channels to stay still prior to the user making a precise measurement. Also, NI-DAQ automatically queries the module to decide when the module outputs are settled. The NI device measures 1.2 x 6.8 x 8.0 in. in physical dimensions.

SCXI-1126 Obsolete Status has been announced by National Instruments, but the module will still be available for purchase and repairs by Apex Waves.