A communication device and method for electronic price label (EPL) systems which use EPL components. The device includes a microcontroller, a first EPL circuit enabled by the microcontroller which sends a first signal to an EPL computer in response to a first polling signal from the EPL computer indicating...http://www.google.com.hk/patents/US6035437?utm_source=gb-gplus-share專利 US6035437 - Communication device and method for electronic price label systems
