+++ ==ERROR: No output for this page==
A Unified User-Friendly Instrument Control and Data Acquisition System for the ORNL SANS Instrument Suite  
[PERSON]  
ey
[PERSON]  
ey
[PERSON]  
ey  
++  
the high flux isotope vector (HFIR) at ORNL. While there is much overlap among the instrument specifications, each of these instruments has unique advantages for different types of experiments. Thus, there is considerable overlap in their user bases, who use multiple instruments for different experimental needs, such as specific performance or sample environment equipment needs. The SANS instrument suite has had very different instrument control and data acquisition systems (IC-DASs) over the past decade for historical reasons. EQ-SANS, located at the SNS, relied on PyDAS, a Python extension of the original home-developed SNS DAS [2]. Bio-SANS and GP-SANS, both located at HFIR, were served by a customized graphic user interface (GUI) extension based on the Spectrometer Instrument Control Environment (SPICE) software built on LabView [3].  
At the SNS, the original SNS DAS played a critical role in the commissioning and operation of early instruments. It also laid the foundation of the data format for timestamped event mode data coming from the pulsed neutron source, which is required to record the time-of-flight of each neutron for further data process and reduction [4; 5]. Later instruments with higher data throughput were commissioned at the SNS and exposed the data acquisition bandwidth limitations of the original SNS DAS. Years of operational experience also highlighted the need to improve the reliability and usability of the original SNS DAS. As a result, a series of significant software and hardware upgrade projects have taken place at the SNS [6; 7; 8; 9], using the Experimental Physics and Industrial Control System (EPICS) toolkit and Control System Studio (CS-Studio) [10; 11; 12] that are used by the SNS accelerator control system. EQ-SANS at the SNS was the first among the SANS suite to be upgraded to the EPICS-based IC-DAS.  
Over time, significant upgrades at Bio-SANS and GP-SANS, including upgrades allowing them to use the same type of \({}^{3}\)He linear position-sensitive detectors used at EQ-SANS [13], neutron collimation systems, and additional sample environment equipment [1], have challenged the existing capabilities of SPICE and DAS. For example, the timestamped event mode data from the detector system have been converted to histograms to be handled by SPICE, losing valuable temporal information for neutron detection at Bio-SANS and GP-SANS. Moreover, given the growing suite of sample environment equipment shared among the SANS instruments and the need for a unified user experience, it is imperative that Bio-SANS and GP-SANS follow suit to upgrade to the EPICS-based system. This unification of the IC-DAS also will make system management and operation easier without splitting resources on what otherwise might be two separate development efforts.  
This article shares our user needs and requirements analysis results, key methods we relied on, and new features of the EPICS-based SANS IC-DAS. Besides basic instrument control and data acquisition features, our new system is ready to be deployed for other similar SANS instruments, offering accurate and intuitive metadata handling, sophisticated experiment planning tools, and different user operation interfaces catering to different user communities.