Abstract: A sideband communication system has been developed for a conveyor system. A controller card controls the operation of a conveyor zone and communicates information about each conveyor in the conveyor zone. The controller card is assigned to control and monitor the operation of one or more of these zones of conveyors. The cards of adjacent zones are daisy-chained together to facilitate communication with one another and with other systems like a programmable logic controller (PLC). In addition to the standard controller area network (CAN) communication protocol, the controller cards further communicate amongst themselves using a sideband communication protocol that is outside the realm of the standard CAN communication protocol. The sideband communication protocol allows the cards to communicate with each other without interfering with normal network communications which provides additional capabilities such as automatic card self-identification.