Revert "Merge pull request #83 from ncharles/ust_3444/dev/3446_read_data_from_external_file"

This reverts commit 8b166a669efe8a95d58a3d63ed460fad93032f8b, reversing
changes made to 56d4a6e5f1197b56f3302829bd08f15fc06c8e31.