專利摘要：
Disclosed is a method for operating a system of first and second readers. In the method, a processor is provided to produce a command. The command is used to get the first reader in an active mode and the second reader in a standby mode. The second reader is wakened up so that the first and second readers are in the active mode at the same time. The first reader is switched to the standby mode while the second reader is retained in the active mode.