programmation par tambour

CONT: AC256 is an old product line from Andover Controls Corp. ... Some general info about the AC256: Programming is accomplished with drum programming [where] each drum has control lines, a comment line and an emergency line. In the programming there are things like flags, counters, conversion variables, expressions and external variables.
OBS: [The patent] disclosed a novel programmable sequence controller employing a revolutionary programming method, herein called asynchronous drum programming, wherein a digital computer simulates a plurality of drums, each comprising a plurality of drum lines. Each drum is assigned to a particular output to be controlled and each drum line contains one or more logical statements providing exit conditions to further drum lines. This programming method allows ordinary maintenance people to program such programmable controllers for use in energy management systems.