Patent attributes
A slave module, connected in series with a master module on a communication line, configured to control switches to sequentially assign identification numbers of the slave module and lower slave modules, the slave module comprising: a first communication line connecting a processor to one of an adjacent upper slave module and the master module; a second communication line connecting an adjacent lower slave module to the first communication line; a switch on the second communication line and configured to control a communication connection between the first communication line and the adjacent lower slave module; and the processor configured to control an operation of the switch based on a signal received from the first communication line, wherein the processor is configured to close the switch when setting of an identification number thereof is completed based on an identification number received from the master module through the first communication line.