ACM

Abstract Control Model. Using real world values to talk to an automated light, rather than meaningless and arbitrary DMX values. For instance, a strobe function would be called out in flashes per second, or Hz, instead of speeds: strobe1, strobe2, strobe3.

See the white paper http://www.etdimming.com/clientuploads/docs/MarqueeACM.pdf by Robert Bell for excellent discussion and further explanation.