[en] Data acquisition for the Sodium Loop Safety Facility (SLSF) experiment P4 used three computers for the continuous collection of data and two computers for the routing and displaying of data. Four of these computer systems were located at the Engineering Test Reactor (ETR) site, in Idaho, to access sensor signals from the analog to digital interfaces. The fifth system was located at Argonne National Laboratory (ANL), in Illinois, and was used mainly for display and storage of data. All display computers were connected together using the DECNET software package. The transmission of data was managed over a dedicated phone line using 9600 baud long distance modems. A stand-alone high speed data acquisition system was also used to record data during planned reactor transients