Knowledgebase: Terminology
Posted by Squarell Support on 09 December 2013 10:30 AM

ACK (Acknowledgment) is used to provide a handshake mechanism between transmitting and receiving devices. The sending device can only proceed after the receiver acknowledged the previous message. If a transmitter detects a recessive level in the ACK slot it knows that no receiver found a valid frame. A receiving node may transmit a recessive to indicate that it did not receive a valid frame, but another node that did receive a valid frame may override this with a dominant. The transmitting node cannot know that the message has been received by all of the nodes on the CAN network.