In communications, a subchannel that is derived from the main channel. It is used for diagnostic or supervisory purposes, but does not carry data messages.
"secondary channel." YourDictionary, n.d. Web. 20 May 2018. <http://www.yourdictionary.com/secondary-channel>.
secondary channel. (n.d.). Retrieved May 20th, 2018, from http://www.yourdictionary.com/secondary-channel