Patent ID: 7053862

Claim:
A display unit configured for use in a sign display panel, the display unit comprising: a memory; a display output device; an interface configured to communicate with a controller of the sign display; and a central processing unit configured to: receive, through the interface, one or more messages of a first type, the one or more messages of the first type communicating multiple frames of display data; store a plurality of the received frames in the memory upon receipt; receive, through the interface, a message of a second type containing a display instruction, the display instruction instructing the display unit to display one frame of the stored frames; and process the one frame to update the display output device upon receipt of the display instruction; wherein the first message type is a local message containing an address for a particular display unit; and wherein the interface is configured to connect the display unit between a controller and an other display unit in series, and wherein the display unit is configured to, upon receipt of a local message: check the address; and if the display unit is not the particular unit: decrement the address; and send the local message, with the decremented address, to the other display unit.