DAQ Controllers

A Data Acquisition (DAQ) Controller allows cameras to be synchronized & triggered with external measurement devices, input signals, and output real-time DIC data. As such, a DAQ Controller performs multiple functions that enhance & expand the capability of a DIC system and measurement application scope. A DIC system can always be retrofitted with a DAQ Controller if and when testing requirements change.  

DAQ Controller
Figure 1 – DSM 25022: DAQ Controller 

For one, a DAQ Controller allows data from up to 8x (+/-10V) external analog devices, such as load cells, LVDTs, crosshead transducers, strain gauges, extensonometers, thermocouples, to be (input) read into Istra4D. The DAQ Controller has an internal 16-bit A/D converter with a max sampling rate of 250 kS/s, which is synchronized to the recording of the camera acquisition frame rate. Analogue data is recorded and saved together with the measurement image within one HDF5 data file.  

Front side of the DAQ Controller
Figure 2 – Front Side of the DAQ Controller 

2x (+/-10V) analogue outputs are also included in the DAQ Controller that allow real-time (in-situ), online DIC measurements to be exported from Istra4D into i.e. a materials testing machine or external DAQ controller.  

The “Trigger In” port allows a TLL signal to start (trigger) a ringbuffer recording. A ringbuffer recording saves acquired measurement images directly to RAM of either a Laptop PC or Tower PC, or on onboard camera memory (i.e. for high-speed SpeedSense cameras).  

Rear side of the DAQ Controller
Figure 3 – Rear Side of the DAQ Controller 
 

The “Sync IN” port allows an external analogue triggering source (typically, a sinusoidal or pulsed wave) to be read-into the DAQ Controller. This allows cameras to be synchronized and triggered based on an externally generated signals, which is required for vibration and fatigue testing applications. Camera triggering can then be performed at peaks, troughs (valleys), or at specific phase change increments.