Concurrent 3 : Acting in conjunction; used to describe a situation wherein two or more control devices exist in an actuated condition at the same time (but not necessarily simultaneously)
NFPA 79 Electrical Standard for Industrial Machinery, 2002 ed. http://www.nfpa.org/assets/files/AboutTheCodes/79/ 79-A2002-rop.pdf, (Electr Std for Ind Machinery - Amer) {225 NFC}