Omron has built-in safety measures that protect communications from device synchronization errors. When users connect to an Omron PLC that gets a bad or incorrect Unit ID from the communications connection, it will go into a wait mode. This can sometimes last for several minutes while the PLC waits for the communications connection to clean up. Even when the Unit ID is changed on purpose, the Omron PLC assumes a communications error. The only solution is to correct the error and wait for the Omron PLC to start responding again.